How to Prepare for Climate Change: Intro

It’s Thanksgiving weekend, and for many podcasts, a week off. But we didn’t want to sock you with some re-run—or, worse, leave you with no episode at all. So David Pogue is here to offer a free chapter from his audio book, “How to Prepare for Climate Change.” You’ll hear the complete Introduction, which is designed to teach you the difference between mitigation and adaptation—and convince you to keep doing the former, but start doing the latter.

Who Makes the Fake Languages for Hollywood?

Season 1 • Episode 6

The first time you heard “Star Trek” characters speak Klingon, or the “Game of Thrones” characters speaking Dothraki and High Valyrian, you might have assumed that the actors were just speaking a few words of gibberish, created by some screenwriter to sound authentic. But these are complete languages, with vocabulary, syntax, grammar, and even made-up histories. There’s only one person on the planet whose full-time job is creating them—and these days, he’s swamped with requests. No doubt about it: Conlangs (constructed languages) are the new special effect. Me nem nesa! 

Guests: David Peterson, author/linguist/full-time language maker. Mark Okrand, author/linguist/creator of Klingon. Angela Carpenter, linguistics professor at Wellesley College.

Episode transcript

Theme begins.

What would “Star Trek” be if the Klingons didn’t speak Klingon? 

[Klingon sample]

What would “Game of Thrones” be if Danaerys didn’t speak High Valyrian? 

[Valyrian sample]

Those are invented languages, complete with syntax, grammar, and vocabulary, commissioned by Hollywood executives. But where did they come from? Who makes them up? And what happens when people tear these languages out of movieland—and into the real world? I’m David Pogue, and this is “Unsung Science”: the stories behind amazing accomplishments in science and tech.

[Theme ends.]


Season 1, Episode 6: How Fake Movie Languages Become Real.

[Music begins]

I don’t know what you did with your pandemic. But checked off a bucket-list item I’d been putting off forever: I finally watched “Game of Thrones” on HBO Max. All 73 hours of it. Including the final season, which was …everything people said it was. An absolute dumpster fire. Nonsensical, rushed, and just so dumb.

Otherwise, “Game of Thrones” is pretty great. It’s a sprawling fantasy epic, set in a pseudo-Medieval, sorta-kinda Europe. There are hundreds of characters. Most of them speak English—with, for some reason, British accents. 

Jamie: You don’t have to do this. You don’t have to do anything.

Tommen: I have to answer to the gods.

Jamie: Not when you’re sitting in that chair!

But because these are made-up tribes from made-up lands, some of them speak made-up languages. For long stretches. With subtitles.

[Dothraki sample]

That’s Dothraki, spoken by the nomadic horseback warriors of Essos. 

[Valyrian sample]

And that’s High Valyrian, which is the “Game of Thrones” version of Latin—a dead language from a long-dead empire, kept alive mostly by scholars. 

Dothraki and Valyrian are only the latest in a grand tradition of phony languages—better known as constructed languages, or conlangs—from movies and TV shows. The only Hollywood conlang more famous than Dothraki and Valyrian is, of course, this one:

[Klingon sample]

That’s Klingon, spoken by the Klingon aliens in the “Star Trek” TV shows and movies. 

Marc: I’m Mark Okrand, and I guess I’m best known as the person who devised the Klingon dialog for Star Trek. 

David: I mean, in your real life, you’re a linguist, right? Has Klingon taken over your life? 

Marc: Now it has, because now I’m retired. So—so yeah.

Yes, Marc Okrand is the man who created the Klingon language. But his first movie conlang wasn’t Klingon. It was Vulcan, and the movie was “Star Trek 2.”

And how he got that gig has got to be one of the goofiest, most reverse-engineered stories in all of screenwriting. 

Marc: There’s a scene where Mr. Spock and the new Vulcan character named Savik have a little discussion with Captain Kirk, and then Kirk goes off to look around. And Savik says to Spock, “he’s so human.”

And Spock says, “nobody’s perfect.”  

That scene was filmed with the characters, the actors speaking English. When they went into post-production, they said, “why are they speaking English?” 

Why aren’t they speaking Vulcan?” 

The producers decided that the simplest fix was to hire a linguist to watch the scene as it was shot in English, study the actors’ lips as they spoke, and make up some fake Vulcan syllables that matched their English-language lip movements. The actors would then dub those Vulcan words over the existing scene, and English subtitles would tell the audience what the Vulcan words meant. 

Marc: So I made up gobbledygook. I watched the scene, made up some gibberish that matched, I hope matched the lips. 

Worked one day with Savic, who is Kirstie Alley—

[Savic line]

—worked a couple of days later with Spock, you know, with Leonard Nimoy. 

[Spock line]

Then I drove away, realizing that I had just taught Mr. Spock how to speak Vulcan, which was very cool, and I thought this is the end of my “Star Trek” career, probably the end of my movie career. 

It was not. A year and a half later, producer Harvey Bennett called Marc up and told him about a new movie with Klingons as the villains.

Marc: ”OK, now we’re making this other movie. You did the Vulcan. You want to do Klingon?”

He did.

Now, the first “Star Trek” movie had included a little Klingon—a handful of very short utterances, written by producer John Povo and James Doohan, the actor who played Scotty. 

Marc: The longest one is three syllables. 

[Klingon lines here] 

John and Jimmy who made it up, I think, were not all that concerned about grammar and vocabulary, and that sort of thing. They wanted to make a weird-sounding language. That was the goal. 

But for “Star Trek 3: The Search for Spock,” released in 1984, the producers commissioned Marc to compose a full-blown, working language.

Marc: I made up a grammatical system, made up, you know, a phonological structure, you know.

David: Did Harve give you any kind of a brief, or a goal? I mean, did he say “I want it guttural and harsh,” or—

Marc: Guttural is exactly the right word. It’s actually in the script.   it says in the script, “Krug says, in his guttural Klingon, blah, blah, blah.” so I assume what they meant by that is cccchhhhh kinds of sounds. 

Most words are one syllable. It’s very abrupt, because it’s full of glottal stops. So it’s kind of chunky. And a lot of velar and uvular fricatives, the stuff in the back of the throat that’s noisy.

[Klingon sample]

Marc: In terms of the grammar, it’s pretty straightforward. It’s got no tense, it’s got no gender in the sense of sex— sexually based gender. Yeah. No agreement and so forth.


In general, the Klingon language matches the Klingon personality: hostile and spitty. It doesn’t even have words for courtesies like “Good morning” and “Nice to see you.” People come up to Marc all the time and say, 

Marc: “You’re the language guy, say something in Klingon. Say ‘hello, how are you?’” I say, “a Klingon would never say that!” (laughter)

Once Marc had created his conlang, he recorded himself speaking the Klingon parts on cassette tapes, which he mailed to Paramount. The actors learned their lines by listening to those tapes.

Marc: And then I went out to Hollywood.   most of the time I’m just outside the frame when they’re speaking Klingon. 

David: So you’re on set.   cameras rolling and union sound technicians and key grips….What do you do when the actor says it wrong? 

Marc: Well, I learned really quickly what you do!

You know, when you make a movie,   the director yells, “cut,” and then the director checks with the camera person. “Is that OK?” “Yeah, it was OK,” or “no,  there was a shadow from the microphone.” And if there was Klingon, check with me. “Was that OK?”  

Well I learned very, very quickly not to give “no” as an answer very often, because they were annoyed.   time is money.   So if the actor said it and set it wrong, but it still sounded like it could be Klingon to me, I’d say it was fine. 

I would just keep notes.   The individual words sometimes would change from one thing to another, and sometimes even the grammar would change, as a result. 

Klingon’s evolution is filled with accidents like that—where actor screwups wound up shaping the Klingon language for all future generations. Like the scene in Star Trek 3 where the Klingons have taken three human prisoners.

Marc: And Krug really wants something from Captain Kirk.  And he says:

Krug: And now to show you that my intentions are sincere, I shall kill one of the prisoners.

Marc: And then he says, in Klingon,   “kill one of them. I don’t care which one.” 

And the way to say that in Klingon,   is “WAAT! Yehoch?”—which means “kill one”— “whyte yeschoch,” which means “I don’t —I don’t care about who.”  

So it’s time for Krug to say the line. And he says, you know,  “YaHOCH! JeHASpach.” 

Krug: YaHOCH! JeHASpach pei!

Marc: And then Nimoy yells “cut. That was great!” And Christopher Lloyd says, “I blew it.   I said the line wrong,” which is true. He left off the waat and he left off the vyte. 

Krug: YaHOCH! JeHASpach pei!

Marc: And Nimoy says, “Marc. How did the Klingon sound to you?”

David: Oh, boy. 

Marc: So there’s only one possible answer I could give, and I said “the Klingon sounded fine,” and then I thought to myself, Now what? Because what he said in the first line was kill. And the whole point is “kill one.”

David: Right.

Marc: And I thought about it,   and I said, “ah—here’s what we’ll do. This little prefix ye, that means it’s an imperative, it’s a command, is still a prefix that means it’s a command, but you only use it with a singular object.”

David: Oh, man. And this is how languages evolve!

Marc: Exactly. So things changed as a result of moviemaking. 

David: And that doesn’t violate your— your purist sense of integrity?

Marc: Uh, not with Klingon at that stage of the game, because nobody knew anything about this language except for me. So  I could make up new rules and bend things.  

Eventually, Marc Okrand wrote some books that documented the Klingon language. They became the bibles for wannabe speakers all over the world. 

David: So how much then, is Klingon a usable language? Is there enough vocab? 

Marc: Oh, totally. Well, there’s not— not yet enough, but it’s growing.   

Today, there’s a Klingon Language Institute, which holds an annual five-day Klingon conference and oversees the translation of various works into Klingon, including the Bible and several Shakespeare plays. 


Here’s the famous “to be or not to be” soliloquy from Hamlet:

[Klingon soliloquy]

Or, more precisely: “To continue, or not to continue. Now I must ask this.”

[Soliloquy repeat]

The language-learning app Duo Lingo offers a free Klingon course, right alongside French, Italian, and Spanish. It sounds like this:

[DuoLingo sample]

And during ​​ period that Netflix had “Star Trek: Discovery,” you could turn on Klingon subtitles for the first episode. That might have been useful for the 30 or so people who speak fluent Klingon. One of them is a guy named d’Armond Speers, who raised his son with Klingon as his first language. 

Meanwhile, Marc also helps to keep the flame alive.

Marc: The Klingon Language Institute meets annually. And they send me ahead of the meeting, they send me a list of requests for new words. 

David: So you are still the keeper of the leather-bound book. You don’t—you don’t let people make up their own words. 

Marc: It’s not a matter of let. It’s not my choice. It’s their choice. The Klingon speaking community at some point decided that I would be the sole source of new vocabulary and the sole source of solving grammatical or resolving grammatical disputes. They didn’t even ask me to vote on that.  

David: Did I read that you have a fake informant?

Marc: He’s not fake! No, there’s a guy named Maltz. Yeah, in Star Trek 3,   There’s Krug,   And he’s got two helpers named Torg and Maltz. And at the end of the movie, all the Klingon are killed except for one. This is Maltz, right? And he’s taken prisoner. So I’ve decided, well, he’s taken    prisoner, I’m going to grab hold of him and learn the language from him.

David: So when someone comes to you with a question, you say, I’ll ask Maltz? 

Marc: I’ll ask Maltz. And everyone plays along with this. “What does Maltz have to say about… da da da?”

After the break: We’ll meet a linguistics professor who can teach you how to make your own constructed language…and the man who created all of the “Game of Thrones” languages.


In the Wellesley College course catalog, this is the description of Linguistics 315, “Invented Languages:”

“Over the centuries, invented, or artificial, languages have been devised for many reasons.  The vast majority have failed, but why? Is there a place for invented language? Students will design their own miniature artificial language.”

The professor is linguist Angela Carpenter. She says that invented languages are by no means a new thing.

Angela: Not really, no. One of the earliest attested artificial languages was done in the 12th century by a nun, a woman called Hildegard von Bingen, and she created a language called Lingua Agnota and documented it. 

Now, aside from fake movie languages, the only constructed language I’d ever heard of was Esperanto, which a Polish eye doctor named Ludwig Zamenhof created in 1887. 

Angela: So his idea was to bring the world together in peace.   

Supposedly, about 100,000 people worldwide can speak Esperanto today. Mostly to each other.

David: Would you say there are any other constructed languages that have come anywhere close to actually being spoken in the world? 

Angela:  One could say modern Hebrew is an example. 

David:  Whaaat?

Angela:         Yes, yes, because Hebrew as a spoken language died out.  It was written— it was used for religious reasons, for prayers, et cetera. But as an everyday language, nobody was speaking Hebrew for—since, like I think maybe 200 A.D.  

Enter Russian newspaper editor Eliezer Ben-Yehuda, in the 1880s.

Angela:  He deliberately set about reviving Hebrew. But here’s a problem. Hebrew, as a written language, was missing a lot of vocabulary. I mean, in the Bible, there’s no word for button, or telegraph, or train. Right? 

So Ben-Yehuda invented new words for modern concepts, and promoted Hebrew as an everyday, spoken language.

Angela:  Today, whatever the population of Israel is, that many are people speaking Hebrew. So one could say,  spoken Hebrew is basically a newly constructed language. 

Now—you, dear listener, are unlikely ever to take Linguistics 315 at Wellesley; Professor Carpenter accepts only 15 students at a time. So I invited her to give us a crash course in how her students develop new languages from scratch—right now.

David: I mean, do you say, “Decide what the letters of your alphabet will be, decide what the sound is going to be, whether it’ll sound angry and Germanic, or lulling and soothing?”  

Angela: Well, you hit the nail on the head. We start with the sounds. they get to choose the consonants and the vowels. And in my class,   I encourage them to —actually I require —that they choose some sounds that are not English. 

We also want them to choose the syllable structure. Syllables can be very simple, like what we call a consonant vowel syllable like la, ta, day, right? 

Or you have English which can have a syllable like Sprite—S, P, R—right? So you can start with a very complex consonant cluster.  Then they have to do a stress pattern. 

So English is a language that has—every multisyllabic word has stress on one side, right, telegraph, right, acrimonious, right, so they have to decide on that. 

When you put those things together, your syllables and your stress pattern, you get a particular rhythm of your language. They kind of get, “this is what my language is going to sound like,” even if they don’t have the words yet. 

David: Huh!

Angela: One student wanted a language, a peace loving language. Very interestingly, she had two versions of her language, the regular version, which used as what we call voiced sounds, so buht guh vuh zuh. That’s a voiced sound, right? 

That student’s name is Sam Burke, and here’s what her regular, extroverted dialect sounds like. You’ll hear some V’s and Z’s in there.

[Extroverted sample]

Angela: But when her speakers wanted to go into an introverted state, they changed all their sounds to voiceless sounds. So now it’s like fff sss ttt —words like that. 

David: Cool!

[Introverted sample]

David: I see. So voiced versus unvoiced so— like, they’re the same lips, right, fffff, is the same as vvvv. But in one, your voice box is activated, and the other isn’t?

Angela: Exactly. Fuh and vuh are the exact same sound, just different in terms of voicing. 

David: And then at some point, they’ve got the rules now—they just start making up words that fit the rules they’ve got?

Angela: Yes. The first thing I have them work on are their verbs, their tenses. What tenses are they going to have? Not all languages have the same tenses as English. Some languages have several future tense, or several past tense. Right? 

I give them assignments such as, “Come up with 25 verbs.” And depending on the culture, there’s some basics: you need walk, run, locomotion of some sort, you know, eat, that sort of thing.  

Then after, we move from verbs, we go to nouns. Nouns also carry a lot of information, right?  Is it one person? Two people? Three people? Gender. Some languages have gender.  

David: I think about le and la in French, or the three of them in German. 

Angela: Yeah!   

David: So presumably at the end of this class, this —each student has some semblance of the beginnings of a language system, right? 

Angela: Yeah, they have a pretty good language system. Many of them have up to a thousand words, by the time they are done. 


Constructed languages have always been sort of a nerdy niche, occupied by leagues of language-loving linguists. But in the worlds of scifi and fantasy shows and movies, they’re catching on like wildfire. They’re featured in movies, like the new remake of Dune, Doctor Strange, Thor: The Dark World, Raya and the Last Dragon, and Bright, and in TV series like Defiance, Emerald City, Dominion, Another Life, Lovecraft Country, and Shadow and Bone.

All of those invented languages have something special in common: David J. Peterson. He wrote them all. And the languages in “Game of Thrones”: In the world of Hollywood conlangs, David J. Peterson is the Man.

Pogue: So at this point, are you able to make a complete living from generating languages for people? 

Peterson: Yeah, that’s been the case since, I think, 2015. 

Pogue: I mean, there can’t be more than five people in the world who do that full-time. 

Peterson: I think there’s just one. 

Pogue: It’s you?

Peterson: Yeah. Yeah. 

David is also an author, a linguistics professor, and probably the most famous conlanger working today. To say that languages have always interested him is the understatement of the century.

Peterson: When I was 17, I woke up one day and from a dream quite suddenly, and felt very ashamed that there were millions of people that spoke French and I wasn’t one of them.  

And so I made it my goal to learn French that day, and then to learn every language on the planet, which I thought couldn’t have numbered more than like 60 or 70.  

At UC Berkeley, he took Arabic the first semester and Russian the second. And then one day…

Peterson: There was advertised on my dorm, just a little slip of paper, a student-taught class on Esperanto. 

I had heard of it. I had heard that Esperanto was this language that somebody created, which sounded goofy to me. How do you even do that?   So I have to take this course.  

It was just fun. It was just absolute— an absolute joy.  And somewhere in the middle of that first semester, I thought, “what if I created a language that — what if I just created it for my own personal use?”   And so basically I started right then in class and I kept up with it. I kept up with, you know, creating languages for fun as long as it’s been fun. So it’s been 21 years now. 

While getting his master’s degree in linguistics at UC San Diego, David Peterson helped to start the Language Creation Society, an extracurricular group that’s exactly what it sounds like. And not long thereafter, HBO came a-calling. 

Benioff: Dothraki are a bit of a cross between the Mongols and some of the native American tribes. They’re a horse people, they live in these great vast grass plains. And they make their living conquering other people.

This is the voice of David Benioff, one of the two writer producers of “Game of Thrones.” He’s talking to the camera in an HBO bonus video on YouTube.

Benioff: For the series, we actually thought it would be much more believable if we heard them speaking their own language, rather than have them speaking in heavily accented English.

And here’s his collaborator, Dan Weiss:

Weiss: We went to the Language Creation Society, who turned us on to David Peterson, and he created the language, taking into account what we told him and what was in the books.

Yes, there was a little bit of Dothraki in the “Game of Thrones” books. Author George R.R. Martin didn’t invent a whole language, but the snippets he did include were at least linguistically consistent. 

So for David Peterson to create a full matching language, 

Peterson: It wasn’t like “sit down and create the best language you can.”   It was “try to create something that looks like it was there before the books were written.” That was my goal. 

Dothraki was his very first paid language-invention job. Then, for season 3 of “Game of Thrones,” they hired him to create High Valyrian, too.

Pogue: OK, so what are some of those characteristics of, let’s say, High Valyrian? 

Peterson: I’m trying to think of some words that really sound Valyrian. Let’s see. Word for bronze is rrrydazma. And that type of thing. Has the same suffix as, honestly, as actually as genmazzma, which is Daenerys’s last name.

Pogue: Stormborn, yeah.

Peterson When you hear Valyrian, it’s like these,   na na na na, na na na na na. And then you hit these long vowels. So like daldreee, ez buz dahdree, el da’or. You know? That was the line from the show. “A Dragon is not a slave.” 

Pogue: Huh!

It was really cool to interview these famous conlangers, but I couldn’t keep one nagging thought down: Is all the effort really necessary? The audience doesn’t know what the characters are saying. Is it so important to invent an entire language, with all these rules of syntax, and all this baked-in history and culture, if we’re only going to hear a few seconds of it? 

Couldn’t you get away with a little plausible gibberish?

And the answer: These days, not really. These days, everything’s on demand, everything’s on YouTube, everything’s replayable, and the fans are rabid. They care. They’ll scrutinize every syllable. And if you’re not legit, they’ll catch you. 

Peterson: Fans do get it. They do get it. And it doesn’t take them very long. 

I remember I was watching the last season of Game of Thrones. There’s this line of Dothraki where Daenaerys asks, “how many today?,” referring to how much have the dragons eaten. 

[Dothraki: How many today]

Peterson: (cont’d) And the —he says the Dothraki for “three sheep, ten goats.” 

[Dothraki: Sheep and goats]

But the subtitles say, like, “nine sheep, 12 goats,” something like that. 

And the episode wasn’t done airing before somebody noticed the error and tweeted at me and asked what was up, and I didn’t even know what they were talking about. So I went back in and I looked. I was like, oh, my God, they’re right. 

I was like, did I just make a mistake, that I read the wrong number? But I went back to the script. It’s like, no, I did the right numbers. 

They just decided, “nah, that’s not enough sheep and goats. It’s gotta be more than that.” But then they didn’t have me retranslate it or reshoot it. They just changed the subtitles!

Pogue: Oh my gosh! That’s not showing much respect to your craft. 

Peterson: Well, I mean—  The thing that bothers me and boggles my mind is like, who made that decision? Who was like, “No! No, that’s not enough sheep and goats. Nobody’s going to believe it. We have to change it.”   Like which —which people in the audience— would they be like, “Not enough sheep and goats.” (laughter)

Lately, a flood of new commission requests is coming David Peterson’s way. First, because “Game of Thrones” was so successful—and second, because movie production is ramping back up as the pandemic lockdown throttles back down. 

Pogue: Can you remember any of the requests, the descriptive requests, that you’ve gotten for projects? do they say “I want an angry sounding language,” “a loving sounding language?”

Peterson: Yep. Like honestly, all the all the ones you’ve thrown out, yes. Some of the descriptors are —  harsh, soft, beautiful, whatever.  

And sometimes they mimic descriptions like, ah, just kind of like do a little gibberish line of what they’re hoping it would sound like. And it’s—it’s really cringeworthy. But, you know. If they— if they talk for long enough, I know what they mean. 

Pogue: Let’s say I come to you with a project, and it’s— it’s an alien race that are just schmoopy lullabye speaking, conflict-free. 

Peterson: With something like that, the first question is like, “OK, they’re aliens—are they human aliens? Are they alien aliens?” You know?

Pogue: Oh, I see. 

Peterson: In other words, like, are — are these forehead-ridge aliens, or are these aliens where it’s like, they don’t have ears, they don’t have mouths. Instead they have these two little pincers that they go ts-ts-ts, and that’s it. 

Pogue: Uh, OK. They’re human—humanoid.  

Peterson: Yeah. So like probably what I — I love me some weak fricatives when it comes to that. Weak fricatives are things other than S and Z. So sss and zzz are very—are sibilant, and like things fff, hhhh…sssh can sometimes be a sibilant but it’s like something along in that range. Long vowels, vowel sequences. So it’s like just something like,   Guy you aswannnn annnay. You know? Something like that. 

Pogue: Wow! that’s amazing!

Yeah…Sorry about that falsetto thing. But I mean, he just invented the first sentence of a new conlang in five seconds. 

Peterson: Guy you aswannnn annnay.


Pogue: Can you say something in Dothraki off the cuff? 

Peterson: Probably.  

Pogue: Can you say, “bring me 10 goats?”

Peterson: Oh, my goodness. No, because I don’t remember the word for ten. 

Pogue: OK, so  bring me four goats.

Peterson: Wait —is it inanimate? Crap. If it’s inanimate it doesn’t have a plural and that’s fine. So it would be —it would be like, you know, “they jussun han, desundai.” “Bring to me four goats.”

Pogue: That was really good. Wait a minute. So, so inanimate or animate objects have different plural situations?

Peterson: Yeah. Basically if —if a noun is treated as grammatically inanimate, it doesn’t get any plural. 

Pogue: What do the actors get then in the script? Do they have a quadrant of what the English would have been, what the written Dothraki looks like, and what the phonetic pronunciation is? 

Peterson: Yeah, actually. They also have another line, which is a word for word translation.   Because, you know, it’s important words like, you know, some actor’s putting like a huge emphasis on one word because they think that it lines up with this English word. And actually they just put all this emphasis on a preposition and it sounds a little silly, you know. 

Pogue: And how do they take to having to learn a completely new language? 

Peterson: Oh, they don’t learn it. I don’t think any of the actors who ever do that ever learn the language. Right? You just have to learn how to pronounce it.  I, you know, just record every single line on MP3 exactly the way that it’s supposed to be performed.  

Very different from the old days. You know, when Marc Okrand was working on the Star Trek movies, he would record his lines onto a cassette tape.  

Pogue: He has said, by the way, that, you know, when actors would make a mistake, it was really awkward for him, like —does he raise his hand and stop a million-dollar-a-day production process to correct some word in Klingon that no one will ever catch?

Peterson: Yeah, I would never feel bad about that.

Pogue: You would correct them?

Peterson: Absolutely! 100 percent. I’m not going to change my language just because they had a slip of the tongue. Pfft. No way.

Pogue: Are there examples in the— in the finished shows where they —they spoke something wrong and you just have to live with it? 

Peterson: Oh tons! Tons. 

Pogue: That’s awful!

Peterson: Well, what can you do? I mean, 90 percent of it is good enough. I’d say like eight to nine percent of it is stellar. And then there’s like, you know, one or two percent of it that’s irredeemable. 

Pogue: Wow. Well, thank you, man.  You are David Peterson, creator of languages, as they would say in “Game of Thrones,” probably. 

Peterson: Gereeeen vassay. Thank you. 

Pogue: In Valyrian? 

Peterson: Yup.


As with Klingon, Dothraki and Valyrian have leapt off the screen and entered the real world. David Peterson published a book called Living Language Dothraki; he’s made a DuoLingo courses for learning Dothraki and Valyrian, and academics now study his languages. And of course YouTube is full of people speaking Dothraki—

[YouTube lesson]

It’s a weird and rarefied field, this conlanging. I mean, if you look at it in a certain way, maybe the world doesn’t technically need more languages than it’s already got. But Wellesley professor Angela Carpenter doesn’t mourn the fact that there isn’t one universal language. 

Angela: I love language. I love the fact that there are different languages. I really do. I admit it would be much more convenient if we could all communicate with one language.  But language has such a richness, such texture.  So I just see different languages as marvelous ways of seeing how humans differ, yet how they’re the same. 

As for “Star Trek” conlanger Marc Okrand? He claims still to be amazed that Klingon, his 1982 baby, has taken on a life of its own. 

Marc: I’m still in awe that that that— that that stuff is happening. It’s sort of like, you know, if you pick up something that you wrote a long time ago and look at it and say, “I did this? how did I do this?” And that’s what I feel like with Klingon. How did this come about? You know. 

I didn’t set out to make a language that people are going to use. I set out to make some lines of dialog for a film. 

How NASA’s $2 Billion Rover Landed Itself on Mars: “Seven Minutes of Terror”

Season 1 • Episode 5

Perseverance, NASA’s latest Mars rover, is a one-ton, $2 billion marvel. The plan was for it to enter the Mars atmosphere going 12,000 miles an hour. The problem: How do you slow it down enough to set it down gently on the surface? You can’t use retro rockets, because they’d stir up so much dust, the rover’s cameras and instruments would be ruined. You can’t deliver Perseverance inside a larger spaceship, because the rover wouldn’t be able to drive out of the landing crater. You can’t even control the descent from Earth, because it takes so long for our signals to reach Mars; by the time the rover received a course-correction instruction, there’d be nothing left of it but a smoking wreck. Yet NASA pulled it off—with a nutty, Rube Goldberg-y, multi-stage, seven-minute-long, completely automated system involving a parachute, an airborne launch platform, and a cable. 

Guest: Alan Chen, NASA Entry, Descent, and Landing Lead for the Mars 2020 mission.

Episode transcript


Seven months after liftoff, the Perseverance rover approached Mars going 12,000 miles an hour. 

The problem for NASA: How to slow it down to a gentle touchdown? You can’t use rockets, because their thrust would make a crater that would trap the rover. 

And you can’t control any of it from earth. It takes too long for a signal to reach Mars.

Allen Everybody’s dying a little bit on the inside, right? That you can’t do anything. 

But NASA pulled it off—with a seven-minute-long chain of tricks involving a parachute, a jetpack, and a rope. 

I’m David Pogue—and this is “Unsung Science.”



Season 1, Episode 5: 7 minutes of terror. How to land a 2 billion dollar Mars Rover when all you can do is watch


Late one night when I was six years old, my parents rushed into my bedroom and shook me awake. “Dave! Dave! Wake up! Come downstairs. Hurry up!” my mom said.

I remember distinctly climbing onto the couch with my older brother and sister. And the whole family watched, on the TV, the first human being step onto the moon.

NEIL: I’m at the foot of the ladder.   I’m gonna step off the LEM now.   That’s one small step for man, one giant leap for mankind.   

By the way—for decades, I never understood what Neil Armstrong was getting at. “One small step for man?” Doesn’t “man” mean “mankind?” That’s like saying, “one small step for mankind, one giant leap for mankind.” Doesn’t make any sense! 

Years later, we learned that Armstrong meant to say “one small step for man, one giant leap for mankind.” Let’s play it slower:

NEIL: That’s one small step for man, one giant leap for mankind.  

Well, I don’t know. Maybe he intended to say “a man,” but he swallowed it or something. But anyway, “one small step for a man” makes it a much better quote. Now it’s contrasting one individual with all of humanity.

Anyway. That moment, in 1969, is when I became …a space nerd. I mean, if my parents rustled me out of bed so I could experience that moment—space must be really important. That’s probably the instant when I got bit by the science bug, too. I distinctly remember saying, “Mommy? Daddy? This will make a great introduction for a podcast someday.”

Anyway. Fast-forward 50 years. 


I’m standing at NASA’s Jet Propulsion Laboratory—JPL—in Pasadena, California, looking through a glass partition at a huge, dust-proof clean room. Inside, workers in white clean-room suits were assembling the latest Mars rover. I was doing a story for “CBS Sunday Morning,” and my guide was Adam Steltzner, chief engineer for the Mars 2020 mission. 

ADAM: at the far left here, you’re seeing the rover.  

POGUE: That’s– that’s the actual thing? That’s going to Mars–

ADAM: Yeah,   those guys working on that thing, the thing they’re working on will go to the planet Mars.


ADAM: Hopefully. (LAUGH) 

Yeah I don’t know if you caught that last word – hopefully. Because landing on Mars is really hard. Over the decades, various countries have tried to land on Mars 18 times—and half of them ended in disaster—usually crashy-and-burny disaster. The Soviet Union is oh for 6; the European Union is oh for 2. China tried and succeeded once. But the U.S. has landed successfully on Mars 8 out of 9 times.

Five of our landings have been rovers—wheeled robots that can move around. In 1997, NASA’s Sojourner, about the size of a microwave oven, proved that we could build a remote-controlled Mars rover. In 2004, Spirit and Opportunity discovered evidence that there used to be water on Mars. In 2012, the Curiosity rover discovered that the warm, wet environment of ancient Mars could have supported life. Not, you know, movie Martians with, like, three eye stalks. We’re talking microbes here—but still.

And now, here I was, admiring Curiosity’s successor, the cornerstone of the Mars 2020 mission. 

POGUE: And what are we calling this rover?

ADAM: Well, you know, we don’t have a name for this rover yet. NASA goes to the students of the nation– the young students of the nation, and sets out a competition and says, “Name our rover.”
  And historically, a young girl somewhere in the middle school era has won that competition.  

POGUE: And why do middle school girls usually get the nod?

ADAM: Well, the boys come up with things like Laser Dreadnought   and Laser Death. And– (LAUGH) and those are great for a Transformer, but maybe not for a rover. The rovers– the– the young ladies come up with   names like Curiosity, and Opportunity and Spirit. (continued)   And so we don’t know what this rover’s name is, but my bet is on a middle– it will be named by a middle school girl. (LAUGH)

Adam actually wound up losing that bet. The 2020 rover was, in fact, named by a boy. 14-year-old Alex Mather from Virginia submitted the winning essay.

MATHER: I named the Mars Rover Perseverance. And I hope that people in the future will look at this rover as a shining example of human perseverance for years to come.


The Perseverance rover looks a lot like the 2012 Curiosity rover—ten feet long, seven feet high, six aluminum wheels—but it’s bristling with a decade’s worth of new technology. It’s got Moxie, a prototype oxygen-making machine. It’s got a UV laser that searches the soil for chemicals that indicate past life. There’s radar that can see 30 feet underground, maybe even spot water. Plus a weather station, an X-ray spectrometer, a laser micro-imager, 19 cameras, and two microphones.

Oh—and a helicopter. A tiny solar-powered helicopter called Ingenuity that can fly for 90 seconds at a time, looking ahead to scope out a good route for the rover’s next move.

On earth, the Perseverance rover weighs more than a ton and cost 2.7 billion dollars. On Mars, its sensors, drills, and on-board lab will look for ancient signs of life and collect samples of the air and the soil. 

ADAM: What we are going to do with Mars 2020,  is we’re going to take samples for eventual return to Earth.   

POGUE: But– but 2020 is not going to bring the sample back.

ADAM: It’s very hard to bring a sample back from the surface of Mars and it takes more than a single mission. 

That’s right: The Perseverance rover will collect 43 samples. One robo-arm will insert each sample into a sterile, sealed little tube; another arm will tuck the tubes into slots in its belly. The rover will drive them to a designated collection spot…and sort of poop them out. 

And then, in maybe 2026, we’ll send a European fetch rover to Mars. It will pick them up, put ‘em in a little space capsule, and blast it into Mars orbit. Eventually, maybe in 2028, a third rocket will swoop by, catch the capsule, and bring it back to earth, where scientists will use all their big, heavy, sophisticated analysis machines to study those samples—and lose. Their. Minds. 

OK—now you know the master plan for Mars 2020. On July 30, 2020, Perseverance lifted off aboard an Atlas V rocket from Cape Canaveral in Florida. 

NASA: Status check! Go Atlas! Go Centaur! Go Mars 2020.  5, 4, engine ignition, 1, zero. And Liftoff! As the countdown to Mars continues! 

For seven months, the capsule containing the Perseverance rover shot toward Mars at about 48,000 miles an hour—15 times the speed of a bullet.

Finally, on February 18, 2021, it entered the thin atmosphere of Mars. The capsule containing the rover detached from the cruise module that brought it there—


—and here’s where our story really begins. 

The rover is the size and weight of a small SUV. It’s inside a capsule going 12,000 miles an hour. The problem NASA had to solve is this: How do you land it gently on the surface of Mars? So gently you don’t smash it? So gently you don’t stir up any dust that might get on the cameras and sensors? It’s the physics problem from hell.

Oh, and before you guess how they did it, get this: The whole thing has to be hands-off. People can’t be involved in this landing. You can’t pilot anything or make any course corrections. You’re 245 million miles away, too far away to send navigation signals. All you can do is sit there in front of a screen, wait for the news from Mars, and have an ulcer.

Allen   for Perseverance, it took about eleven and a half minutes for signals to reach Earth from Mars.   And if we wanted to send the command back, it would take another 11 1 2 minutes. 

This is Allen Chen. He’s worked for NASA at the JPL his entire career. For the Mars 2020 Perseverance mission, he was the EDL lead. That’s Entry, Descent, and Landing. 

Allen (cont’d) You know, everyone’s driven remote control cars before, right? Imagine if you, you know, you saw what the car was doing, you had to wait eleven and a half minutes until you actually could see it. And then you had to wait another eleven and a half minutes to send the command back to that car. That’d be a really difficult way to drive your remote control car, right? 

So, you know, that’s kind of one of the central challenges behind, behind these landings, is that the vehicle has to do it all herself. This is not one of those situations where we have the ability to, to steer things based on what we’re seeing.  

The whole process of slowing down from the outer atmosphere to touchdown was supposed to take seven minutes. 

And during those seven minutes, all NASA’s team can do is sit there, in a stew of helplessness, waiting for a signal to find out if the rover is still alive.

Internally, NASA calls this  period the “seven minutes of terror.”

Montage of announcers and spokespeople:

“Seven minutes of terror”

“That’s the riskiest part of the mission”

“The most elaborate and challenging feat”

“Seven minutes of terror”

“So treacherous it’s known as…”

“The seven minutes of terror”

David So you’re at JPL. By the time it’s all over, by the time you get word of what’s happened on Mars, it could be a smoking heap of wreckage. 

Allen That’s correct. 

David Is that actually a possibility, or has it been so tested and so dekinked that no one really thinks that’s going to happen? 

Allen No, it’s always a possibility.   Every time that you think you have everything figured out when you’re going to Mars, Mars will get you.   there are going to be things that you miss, right? Because things are so complicated.   There’s a reason why we’re all sweating in there. 

OK, so let’s think about how NASA could solve this problem. Your 3-billion-dollar robot enters the Martian atmosphere at 12,000 miles an hour. You need to set it down at under 3 miles an hour. For comparison, 3 mph how fast you hit the ground when you jump …from the height of a physics textbook.

So how do you do that? You can’t splash down in the ocean; they don’t have those on Mars.

You’re probably thinking: Well, duh! Just use a rocket engine. But no, you can’t use rockets down to the surface.

Allen:   There’s a lot of force coming out, those engines pushing into the ground.   you’re worried about the engines basically creating your own tomb, right? You’re digging your own grave. If you are disturbing the ground too much and creating a crater for you to not be able to get out of,   as you’re trying to put the rover down. 

The first time NASA solved this problem, it was 2004, when it sent the twin rovers Spirit and Opportunity to Mars. It used a parachute for initial braking. But then it got nutty: each rover was entombed in what looks like a pyramid-shaped bouncy house, with big bubble balloons bulging out of all sides—the effect looks like a huge freaky clump of white grapes. When the bubble thing hits the ground, 


— it does a bunch of big, high, slow-motion, low-gravity bounces. 

(we hear 2-3 bounces)

When it finally comes to a stop, the balloons deflate, the pyramid opens up like flower petals, and the rover drives out. You can watch a computer-animated rendition of this process on YouTube; I put the link up at It’s quite a sight.

Allen Yeah, yeah. We call those airbags, right?  but Spirit and Opportunity were kind of the biggest things that we thought we could touch down with airbags. If you go back to Spirit and Opportunity, you’ll see that development was fraught with problems of us tearing airbags. And now those rovers were about 170 kilos each. 

In case you’re American and not a scientist, I’ll be translating the metric units for you in this episode. The 2004 rovers weighed 375 pounds. The new one, Perseverance, weighs 2270 pounds. Six times as heavy.

Allen So we kind of had reached the end of the line with what we thought we could do with modern airbag technology in terms of landing heavy things. You know, this was just too big a jump. 

So for the heavier rovers like Curiosity and Perseverance, clearly, the airbags weren’t gonna cut it . On the other hand, one reason they were heavier was that they were built to withstand bigger shocks driving along the rocky Mars surface. Maybe, NASA thought, that ruggedness could be the key to a new landing system.

Allen (cont’d)   we’re beginning to build such a big rover that has   the ability to conform to the ground, and deal with rocks, and has the strength to fall off rocks when it’s driving around on Mars— why don’t we just slow the whole thing down to the point that the loads, that kind of impact forces that we see a touchdown, are the same as what the rover might see when just driving around on Mars?   We don’t need those airbags anymore, because we have a landing gear—it’s already on the rover.

That realization was the beginning of the design for the Sky crane maneuver, which NASA ultimately used for Curiosity in 2012 and Perseverance this year. To the untrained eye, this system looks improbable and convoluted, absurdly over-engineered; it seems crazy that there’s not a simpler solution. It’s a four-step series of braking technologies that slow the falling rover to a gentle bump down on the surface.

During the break, see if you can guess how it’s all supposed to work. 

[theme music]


OK. Before the break, we were talking with NASA’s Allen Chen, who was in charge of the Perseverance rover’s Entry, Descent, and Landing, aka EDL, aka the “Seven minutes of terror.” 

Allen We pretty much have one job, which is to make sure that the rover lands safely in the place that we want to land it. In this case,   We went to Jezero Crater, a place that was so challenging that we weren’t willing to ever go there before, with past missions. 

David So what is dangerous about Jezero Crater?

Allen you can see this giant cliff running through the middle of it. You see lots of big craters out there that are places that even if we were to land there successfully, the rover might not be able to get out of. 

you see all sorts of rocks all over the place that are really dangerous—things that you wouldn’t want to land on.  So that’s kind of that internal conflict there in the mission. We want to go somewhere that we really don’t want to land in. 

David so basically—the Jezero Crater used to be water. Is that what we think? 

Allen Yeah. The scientists believe that Jezero Crater used to be an ancient lake.   if you go to any river delta, you know,   anywhere here on Earth, you’d be hard pressed to not find the signs of life here on Earth. So that’s kind of the idea on Mars, that if we if we find signs of life well-preserved here on Earth in deltas, maybe that’s true, too, at Mars. 

So now, at last, Allen Chen and I shall reveal the answer to the mother of all physics problems: How NASA intended to slow down this plummeting projectile, so gently that it wouldn’t even stir up dust.

Allen We hit the top of the atmosphere going about 12,000 miles an hour or so. At that point, we’re about 125 kilometers off the, off the surface of Mars. 

That’s 77 miles up. And now, meet the first braking mechanism: The Mars atmosphere. Unfortunately, there’s not much of it.

Allen The atmosphere is about one percent, the— the density of Earth.  the lower density is painful. Here on Earth, we have a nice thick atmosphere to use for slowing down. That’s why, you see when the Apollo capsule splashed down, right, there’s only parachutes. They don’t have retrorockets or anything like that because we have a nice, thick, soupy atmosphere to use. 

At this point, the rover is nestled inside what looks like a typical space capsule, with a gently curved heat shield on the bottom. After about a minute and a half of plowing through the Mars air, that shield is insanely hot—like 2300 degrees Fahrenheit, glowing like fire. But inside the capsule, the rover itself rests comfortably at room temperature.

Allen: We hit peak deceleration, about eleven earth Gs of deceleration. So about the amount of deceleration that would certainly cause even fighter pilots to black out. 

Little thrusters start going off, adjusting the capsule’s angle and direction to keep it on track when it hits pockets of denser air.

Allen: The first three-ish minutes of flight through the atmosphere, is really about survival and about steering toward the landing target. 

Allen: At that time,   we deploy this big supersonic parachute. At this point, we’ve slowed down enough to get to the supersonic period where we could safely deploy our 21-and-a-half-meter parachute still going about Mach 1.75 or so. So, nearly two times the speed of sound. 

That parachute is over 70 feet across. Its design has big orange-and-white sections and stripes—which those sly dogs at NASA arranged in such a way that they spell out a binary code. It took internet nerds about six hours to figure out that was an Easter egg, a secret message that said, “Dare mighty things.” It comes from a Teddy Roosevelt quote, and it’s sort of a JPL motto. Google it.

Anyway—it’s a really big parachute. 

David So, so even at 1 100th the density of Earth, the atmosphere is still enough to make the parachute worth it. 

Allen That’s right. It’s still useful. Somebody once told me that Mars has just enough atmosphere to be annoying. That’s not quite right.   we use the atmosphere to slow down.   

Next, a set of explosives is supposed to blast away the heat shield.

Allen: So popping off that heat shield off is like popping off a lens cap. We finally get to be able to see where we’re going. 

Back with Curiosity, we had just a radar, so we can kind of see how fast we were going and how high we were. With Perseverance, we had that plus a camera. This time we could actually take a look at the ground. 

So we’re taking pictures of the ground rushing up at us, comparing those pictures with an onboard map. This is our new terrain-relative navigation system. So we’ve got a picture of the place we’re going. We’ve got pictures we’re taking on the way down. We’re trying to match those up to figure out exactly where we are. 

This new nav system is what NASA thought would let Perseverance land in such a dangerous place. The Mars 2020 team, in advance, had picked out flat spots around the Jezero Crater where it’d be safe to land—and programmed Perseverance to choose one of those spots on its own.

 With one minute until landing, the third braking device is supposed to kick in.

Allen: The parachute’s kind of done its job. You know, the parachute is just not enough to slow us down because the atmosphere is so thin. 

So at about two kilometers above the ground, that’s about six minutes into our seven minutes of terror. That’s when we do the this backshell separation. We drop off from the, from the parachute backshell and let that go, light up those engines and begin that descent toward the ground on engines. 

OK, whoa, whoa, whoa. This is gonna take some description.


Remember, the rover is inside a capsule, which is hanging from the parachute. The bottom of the capsule, the heat shield, is gone now.

So now, the rest of the capsule, the backshell, is going to detach and just float away somewhere, parachute and all, never to be seen again. Or at least not until Elon Musk’s arrives in a couple of years and stumbles across it. 

But what falls out of that backshell is not recognizable as the rover. That’s because the rover is enclosed inside this crablike superstructure called the Descent Stage. It’s a jetpack for the rover. 

Imagine a deck of cards in a box on the table, and you clutch it with your hand. Well, the card box is the rover; your hand is the jetpack grabbing it. Oh, and I forgot to mention—your fingertips all have rocket thrusters, pointing down. Also, you have eight fingers.

Allen: So light up those engines, turn the vehicle to fly there, and slow down even more till we’re coming down directly over that site. 

At 70 feet off the ground, the jetpack is supposed to activate the fourth braking maneuver.

Allen: That’s when we begin that Skycrane period, separate that rover from the descent stage, that rocket-powered jet pack that’s been slowing us down. 

This is the part where it gets really absurd-looking. So your fingers are shooting retro rockets, right? And now—your hand lets go of the card box. It drops straight down,  falling.

What your hand just did? That’s what the descent stage does on Mars at this point. It lets go of the rover—but the rover is hanging from a set of three 21-foot nylon ropes, known as the bridle. That’s what keeps it from smashing onto the ground. Ropes!

Allen It’s a, it’s like a rope. It’s braided. And then there’s an umbilical with a bunch of cables running in there that passes data and power between—mostly data at this point—between the two vehicles. 

And here, finally, we find the ultimate secret of the gentle landing. Yes, retro rockets are involved—but they never get near the ground. The descent stage is going to carry the rover down on ropes. This is the Skycrane maneuver.

Somewhere, Rube Goldberg is smiling.

Allen: Send the rover down below that descent stage and deploy   our landing gear at this point, to put that rover down safely at about 0.75 meters per second. 

That’s 3 miles an hour—and in theory, the rover is now on Mars, fully intact.

Oh, but wait a second—we’re not out of the woods yet. The jetpack thing is still attached to the rover! By those ropes. It’s hovering overhead.

David At this point the— the tethers somehow get cut or disconnected and the descent stage flies away. 

Allen That’s right. 

David What, what makes the decision that it’s time to do that? 

Allen Oh, good question. Let me first backtrack and kind of give you  how we used to do this and how we still do it with landers.

When he says landers, he means three-legged tripod things, like the Viking landers in 1976.  

Allen: And now I’m going to geek out on you. So watch out here a little bit. 

With legged landers, right,   If you touch down on a slope, one leg is going to hit first. And if it hits first, you start pivoting about that point.  you’re going to start flying away from that slope if you accidentally left your engines on. So the, all of these legged landers  have hair triggers—like, you know, really fast detection of, has any leg hit. As soon as the leg hits, we want to shut those engines off and hit the ground. 

Remember how I said NASA has landed eight out of nine spacecraft successfully on Mars? The one that got away was the Mars Polar Lander, in 1999.

Allen: One of the leading theories behind why we lost the Mars Polar Lander is that that hair trigger was set off prematurely. That didn’t detect the impact of touchdown, but instead detected the impact of the legs deploying themselves prior to hitting the ground. 

So one nice thing about the Skycrane is, we don’t actually have to detect the instant of touchdown. We don’t have a hair trigger. Once the rover really settles down on the ground, the, the descent stage jetpack is no longer carrying that weight. And that’s a really strong signal. Really strong, slow signal, right? The weight is gone for about a second to make that decision, which is an eternity in in computer speak. 

that’s when we order the rover to cut the bridle that’s connecting the descent stage and the rover. It uses these little explosive cutters that fire these knives through the, through the nylon bridles and through the electrical connection between the two vehicles. 

David Oh, man, I am geeking out so hard right now. OK, so the descent stage presumably now knows that the cables have been cut and the NASA videos always just say, ‘And the descent stage flies safely away.’ 

Allen Not safely for the descent stage, as it turns out, but it executes about a five or six seconds of, of a turnaround. It first goes up, and then turns, and then flies away about six hundred meters. 

That’s about two blocks away. 2000 feet.

Allen: And going that far ensures that when the descent stage hits the ground,   won’t have any detrimental effect on the rover, right? That’s far enough that when those things explode or rupture, there won’t be a problem. 

David OK,   —so the first slowing down is friction of the atmosphere. 

The second slowing down is the parachute. 

The third slowing down are the jet pack’s rockets. 

Allen That’s right. 

David The fourth slowing down is the crane cables. 

Allen That’s right. 

David And are all of those necessary? For example, as I sit here in my Connecticut living room and try to improve on NASA’s system, why then do you need the parachute? Could the rockets not do the same job as that?

Allen Yeah. You certainly could use rockets to go all the way. However, that requires a lot more fuel.  You need that much bigger a launch vehicle to get it off the ground from from Earth and toward Mars. Everything balloons as you try to try to put more fuel on there.

So there’s a couple of reasons why the, why the parachute still a really good deal for us, although, you know, it certainly provides a lot of heart-stopping moments for us, too, right? 

The parachute? The parachute is the scary part? Of all that sophisticated, autonomous robotics, the jetpack and the heat shield and the pyrotechnic rope cutters—the last thing I’d think would give NASA heartburn is the parachute! I mean, it’s a parachute! There’s nothin’ to it!

But no. The parachutes were the Mars 2020 migraine. 

Allen We wanted to make sure that these parachutes would really work, so we went and tested them supersonically, out over the Pacific Missile Test Range, PMRF, down in Kauai. So a lot of people had a good time hanging out in Kauai for months on end. 


So, you know, when it came time to test these parachutes, we went, went ahead and shot them up high in the atmosphere. So to get to the right density, the low density you see on Mars, we have to go up really high in the atmosphere, and I mean 130,000 feet high. 

But when the when that day came and we tested those parachutes, they turned into confetti cannons. As we deployed those parachutes, they shredded themselves in a matter of, you know, less than a second. The parachute just disappeared. It deploys cleanly, you see it open, and then it’s gone. The whole thing is shredded and torn to pieces. 

So that’s really a heart-stopping moment. I mean, you know, not very proud of having watched that. You know, I was kicking chairs around the room because, you know, suddenly you realize, you know, you make it makes you question everything you’ve been doing.   And then just because we didn’t believe it the first time, we actually kind of made some tweaks to the parachute design   and tested it again. And the same thing happened again, right? That we blew up, blew up this giant parachute again. 

So suddenly, you know, everything was in question, right?   one of the things that we thought we got for free was the parachute . 

So we strengthened our parachute, redesigned it, and then took it up to– to those supersonic conditions high in the atmosphere and proved that it worked. So that took a couple of years of our life that we didn’t expect to have to use there. 

David Well, so that’s the other thing. To what extent are you able to run tests on Earth? 

Allen Yeah,  people always ask us, right, Why can’t you run a full end-to-end test, right?  Why is the first time you do this going to be on Mars? 

And it’s because  things are just too wrong here on Earth. The atmosphere is wrong, right?  You know, Earth does not have the three-eighths gravity that that Mars has. 

Everything is different between gravity, atmosphere, winds, terrain, everything is different. 

So we’ll test engines on their own and characterize how they work and build a software model of that. We’ll test the radar and  try to put together these little building blocks of things we can test, in this end-to-end simulation. And that’s the best we can do, which is pretty disconcerting when it comes down to it.

David I think of computer hardware and software and robotics as– on Earth as a as a process of iteration and beta testing and iteration and selling hundreds of thousands of iPhone 4’s before you make the iPhone 5. You guys are making one-offs. 

Allen Yeah, I mean,  even after developing our new supersonic chute and strengthening it, we only tested it twice. If you take a look at how violent that parachute deployment is, right—you think of parachutes here on Earth as being as being soft, you know, slow, slow inflations here on Earth. On Mars, the parachute inflates in about .7 seconds. So, you know, we have a parachute that’s roughly the size of a Little League infield or so, inflating, you know, in a, in an instant there. If you blink, you’ll miss it. So –and we only tested it twice. So, you know,   there’s a reason my hair is graying much faster than my age. I think it takes it out of you, right. To to think about all those things that can go wrong. 

In any case, you now know, step by step, what was supposed to happen on February 18. Want to know what actually went down? Let’s set the scene for you:

David You are sitting there at—where are you, mission control? 

Allen Yep, that’s right, what we call the crew’s mission support area. 

David Are you, as a person,  able to not completely crunch into a psychological puddle , or are you human like anyone else? 

Allen You know, try not to show it as much as possible. But, you know, everybody’s dying a little bit on the inside, right? That you can’t do anything. And, you know  you’re taking this test in front of the world, right, in terms of whether what you’ve done is going to pass muster or not. What did we get wrong? All those things are racing through your head as it’s going down. So it’s, it’s definitely a coronary event. My blood pressure is probably spiking.

Now, in mission control, someone passes out the peanuts. Oh yeah! You didn’t know about the peanuts thing?

[Music fades out]

 Yeah—so, in the mid-60s, NASA had tried six times to launch its Ranger probe to  the moon—Ranger 1 through Ranger 6—and every single time, they malfunctioned, and we lost the spacecraft.

On launch day for the seventh attempt, engineer Dick Wallace handed out peanuts to the team before the launch—and this time, Ranger 7 lifted off without a hitch. He brought peanuts for Ranger 8 and Ranger 9—flawless missions. So, a tongue-in-cheek superstition was born, and it carries on to this day.

OK, back to Perseverance mission control: 

[music resumes] 

Ten years of work have led to this moment. Al Chen gives a little speech.

Chen: We’re ready to roll.   Thanks for literally and figuratively putting us into the right position to succeed. And let’s land on Mars together. (applause)

And now…there’s absolutely nothing left to do. It takes 11 and a half minutes for the news from the rover to reach the team. Maybe it’s safely on Mars, maybe it’s a twisted pile of smoking metal. Either way, it’s out of the NASA’s hands. They can do nothing but wait out the seven minutes of terror.

B thrusters


Seven minutes to touchdown. Altitude, 80 miles. The capsule enters the Mars atmosphere. Speed, 12,000 miles an hour. Little thruster puffs keep the capsule on target as it falls. 


3 minutes to touchdown. Altitude, 7 miles. Speed, 940 miles an hour. Parachute opens.

C chute


NASA: Navigator has confirmed that the parachute has deployed, and we’re seeing significant deceleration…


2 minutes, 40 seconds to touchdown. Altitude: 6.5 miles. Speed, 350. Explosives blast the heat shield off.

D shell

2 heat shield

NASA: Heat shield sep.

NASA: And the heat shield has been separated. Both the radar and the cameras get their first look at the surface.

1 minute to touchdown. Altitude: 1.3 miles. Speed: 200 miles an hour. The backshell and parachute detach and float away…

E backshell sound

3 backshell

NASA: Backshell sep. 

NASA: We have confirmation that the backshell has separated.


…and the jetpack’s eight engines light up—for about 40 seconds.

F jetpack

18 seconds to touchdown. Altitude: 70 feet. Speed: 3.7 miles an hour. The rover drops out of the jetpack on its nylon ropes. The rover’s wheels unfold to serve as landing gear.

G crane


NASA: Skycrane maneuver has started, about 20 meters off the surface.

And then…and then…after ten years, and after seven months, and after 11 and a half minutes…

NASA: Touchdown confirmed! Perseverance safely on the surface of Mars! Ready to begin seeking the signs of past life. (cheers)

The explosive guillotine cutters cut the bridle. 

H explosive.aiff

The jetpack flies off at a 45 degree angle and eventually crashes.

F jetpack.

Music concludes.

Altitude: zero. Speed: 0. Allen Chen’s heart rate: 140. Probably.

Allen: We touched down actually on Perseverance in six minutes and 59 seconds. So just one second shy of our seven minutes of terror. So little less terror than—than advertised. 

David And then you go on vacation. 

Allen That’s right. 

David the complexity of this thing just absolutely fries my brain. I just don’t know how you pulled it off. 

Allen Yeah, it gives me heartburn every time I think about it, so sometimes you’ve got to think about it a piece of time, right? Break it down and into manageable chunks. Otherwise, you get that paralysis from not knowing where to start. 

David I guess everything’s working. Helicopters work and everything. 

Allen Yeah. So far, it’s gone smoother than any surface mission that I can remember. So—knock on something.

At, you can see some of the incredible pictures and videos the Perseverance has taken—it, and its little helicopter companion. And remember how Perseverance has microphones on it? For the first time in history, you can actually listen to sounds recorded on another freaking planet!

Mars wind

You can hear the Martian wind…

Laser zaps

There’s the rover’s laser, zapping rocks to see how hard they are.

Rover noise

And that’s Perseverance rolling along the surface on its aluminum tires. I don’t know…something there sounds like it needs oiling.

These days, Allen Chen and the gang at JPL are already working on the next project: Getting those sample tubes of soil and air back from Mars in the coming decade.

But for the Skycrane maneuver, Mars 2020 was the end of the line. The spacecraft that NASA is building to retrieve the sample tubes will rocket its way all the way down to the Martian surface—no detachable jetpack necessary. Because it’s going to be a lander, not a rover.

Allen So that’s something that we may not do again. I’d be surprised if we land the rocket with the Skycrane again. 

And you know what? By the time we get those samples back to earth, two missions from now, today’s middle schoolers will be in their mid-20s. Including Alex Mather, the seventh-grade kid who came up with the name Perseverance.

So it’s only fitting that I give him the last word. This is what he said during NASA’s broadcast of the Perseverance landing on Mars:


MATHER: Hello, space nerds! Space is the future, and kids are the future. Learning about space and watching the story of humanity spread to the stars happen is watching the future happen and seeing future unfold. I am currently applying to a science and tech school for high school, with my ultimate goal to join the incredible team of scientists and engineers who are about to make this happen.

Something tells me…he’s got a pretty good shot.

Full landing animation, with all sound effects: https: watch?v=rzmd7RouGrM

Mission control voices for the final sequence:

https: watch?v=4czjS9h4Fpg&t=16s 

Timeline of EDL: apps mars2020 # home?rate=0&id=cruise_stage_separation&time=2021-02-18T15:26:48.003-05:00

Tornado Alley is Shifting Eastward—and We’re Not Ready

Season 1 • Episode 4

Tornadoes are nasty and dangerous. They appear and disappear so fast, there’s usually no time for evacuation—and the United States gets 75% of all the world’s tornadoes, about 1,300 of them a year. They occur all year ‘round, in all 50 states, but the biggest swarm forms in Tornado Alley, in the southern Plains states like Texas, Oklahoma, Kansas, and Nebraska. In 2018, storm chaser and meteorologist Victor Gensini made a startling discovery: Tornado Alley has been shifting eastward. Their growing frequency in Mississippi, Alabama, and Tennessee is a deadly development, because more people live in these areas, often in flimsy housing. And because there are more trees and buildings, it’s much harder to see the devastation coming. 

Guest: Victor Gensini, storm chaser and meteorology professor at Northern Illinois University.

Episode transcript


Theme begins.

In the climate-change era, the disasters you hear about most often are wildfires and hurricanes. And droughts. OK, and flooding. Tornadoes don’t get as much love. But maybe they should.

Victor I think they’re the sexiest of all hazards. 

Victor Gensini is a meteorologist and professor, but above all, a storm chaser. And in 2018, he published a paper that freaked out a lot of people.

Victor Everyone was up in arms, and I had like 500 media requests overnight. 

I’m David Pogue, and this is “Unsung Science.”


Season 1 Episode 4: Tornado Alley is shifting eastward, and we’re not ready

The United States gets 75% of all the world’s tornadoes—about 1300 of them a year. But I’ve never seen one live, and the odds are pretty good that you haven’t either. So when you ask most people to picture a tornado, they picture scenes from tornado movies.

Victor If you’ve never seen a tornado before, your perception of tornadoes was created by Hollywood. And if you look at all the movie covers, “Twister” included, they all have this elephant trunk, high-visible tornado doing damage, people running away from it. Right? A very slender elephant trunk style tornado, high contrast, very visible.

Meet Victor Gensini. He’s a professor of meteorology at Northern Illinois University.

Victor In reality, you can see tornadoes that are miles wide. They’re hard to distinguish what’s cloud based, what’s the surface. They’re very low-contrast. Sometimes they’re happening at night. Sometimes they’re happening downtown Atlanta, Georgia. There are nothing like this beautiful, majestic, just-moving-through-a-wheat-field, “Wizard of Oz” tornado. 

[FILM CLIP Wizard of Oz: “It’s a twister, it’s a twister!”

Gensini may identify as a college professor. But he only got into teaching because the job would accommodate his first love…

Victor The major event that got me into meteorology was when a tornado hit my high school. And I was on a path for engineering and then, like, put the brakes on real quick the next day and said, “Nope, nope, nope, I need to find out more about this atmospheric science stuff.” 

And then, you start to poke around what careers are out there, right? Forecaster, broadcast television meteorologists, so on and so forth. And the professor gig is great, because I get to share my love of meteorology with students. But most importantly, I get to perform whatever kind of research that I think is important to help move our field forward. 

And by “research,” what he means is—

Victor I storm chase. I drive 10 to 20,000 miles every year across the Great Plains looking for these storms. I don’t like to see destruction. I like to watch storms.

I love the landscape. I love the people. Lots of those areas, you know, are—they’ve been untouched since the Homestead Act in the 1930s. I mean, you drive through towns like Boise City, Oklahoma, that still look like, you know, they are a relic of the Dust Bowl in the 1930s. 

David Are you able to describe verbally what these storms sound like when you’re chasing? 

Victor A lot of people say a freight train like, you know, this huge truck driving through my living room. To me, the best analogy that I can give you is standing in front of a massive waterfall like Niagara Falls in that whooshing sound that you hear, almost a—[blowing noises]. 

David Is it a lot of sitting around? I mean, you can’t schedule this. 

Victor Oh. Oh, my gosh. People don’t understand what storm chasing is. Storm chasing is 99.9% driving in a vehicle. So you got to be around people that can make conversation, make you laugh. You get along, you tell stories, you listen to music, right? 

And then that—you know, that tiny point one percent is what you go for, you know. And sometimes they’re great storms, but they don’t produce tornadoes. We’re just looking for the majestic supercells, the beautiful pictures that you see sort of behind me on the wall, right? 

I mean, obviously, this is a podcast, so you can’t see what he’s talking about; I was talking to him on a Zoom call. But they were blowups of stunning supercells: these massive, MASSIVE cylindrical cloud formations, towering up to the heavens. 

Victor Those, those are what we care about. When you get to see things like tornadoes, it’s just kind of icing on the cake. 

And, you know, there’s always something to photograph. Even if it’s not a beautiful tornado in a wheat field, there are still things—skyscapes, sunsets, lightning storms, you know. Old ‘56 Chevies laying in the middle of a field, right, that are rusted out—and there’s always kind of cool landscapes to take in, and that’s I think what all of us are in it for the most, is just to be out there with nature. 

David Oh, so you’re not tornado chasing—you are just storm chasing. 

Victor That’s the key. I think people don’t know the difference, right?  I’m really out there just to see thunderstorms. I love photographing. And, you know, it makes me a better scientist because I get to visually see these storms up close versus trying to model them inside of a computer. It makes me certainly a better forecaster, a better researcher. 

Now, it was news to me that storm chasers aren’t really tornado chasers. I mean, that’s definitely not the impression you get from watching “Twister,” the 1996 movie about storm chasers. 

[Twister movie clip]

ACTOR: I got it! Let’s go, move!…Debris! We have debris!

Yep, that was the tornado movie with the flying livestock.

HUNT: Cow!

COW: Moo.

HUNT: Another cow!

BILL: Actually, I think that was the same one.

Victor I think scientifically, you know, those movies are generally very inaccurate. I think they’re good in that they spark interest in STEM fields in general. I know a lot of people at atmospheric science that got interested in meteorology from the movie “Twister,” despite all of its fallacies and so on. But, you know, they’re not peer-reviewed.They’re not science, they’re just entertainment. They’re just Hollywood. 

David Yeah, well, I wanted to run a line from Twister by you that is made to sound like pseudoscientific jargon. 

Victor Sure. 

David So Helen Hunt says: 

Hunt [from the movie“Twister”]: “Looks like the dry line has stalled. Give me a sector scan west, northwest, look at mid-levels for rotation and increase the PRF.”

Victor I love that line. There’s some credibility to that. If the dry line has stalled, there’s probably strong convergence along the dry line, which means that storms are likely initiating. So when she says ‘west, northwest,’ that would be a preferred area if you were a storm chaser. 

David And how about ‘increase the PRF’?

Victor Oh, yeah, ‘increase the PRF’ would be the pulse range. You’re increasing the amount of the pulses that are being sent out by the radar. 

I think Jan de Bont went to, right, those, those scientific writers and said, “if I were a storm chaser, you know, what would I say if I was all excited about storms developing?”  

David Wow. What do you do when you go storm chasing? 

Victor I do some scientific measurements, right? I will launch weather balloons. We’ll take measurements of the near surface and upper level pressure, temperature, dew point, wind speed, right, all these all these variables that meteorologists care about. But we’re at a very, very safe distance from the storm. And even when I’m actually chasing, trying to get, quote unquote, close, I don’t get into what’s called the bear—bear’s cage of the storm, or in fact, I think Dusty—Seymour Hoffman, in that movie, right, talks about it. “They’re in the Bear’s cage! You could really feel it with a telephoto lens,” right? 

[Bear’s cage “Twister” clip]

Hoffman They’re in the Bear’s cage! Take a peek! You Can really feel it with a telephoto lens!

Melissa No!

Just a side note here: I can’t tell you how much I love that Victor Gensini has the dialogue from “Twister” memorized. Anyway, going on… 

Victor We’re never that close. It’s really scientifically uninteresting when you’re up in there in the tornado, because you can’t see anything! There’s so much rain and dust swirling. The real—the real beauty, honestly, is, you know, several miles away from the storm, kind of taking in the entire, you know, majestic skyscape that these supercells can produce. 

David It seems like in the climate change era, all we hear about is hurricanes, hurricanes, hurricanes. Do you consider tornadoes underappreciated? 

Victor I think they’re the sexiest of all hazards. I think the appeal of the tornado is its short lifespan. It comes and goes very quickly, versus a hurricane. In addition, the damage right after tornadoes is often a little bit more impressive than hurricane damage.

I mean, I’ve seen tornadoes remove homes from foundation and put them in the neighbor’s yard. I’ve seen a smart car thrown three hundred and fifty yards, smashed up like a soda can, vehicles flipped over, roofs torn off, right, houses, well-built homes completely removed from the foundation. And the only thing that is remaining are bolts that are being pulled out of the concrete. 

I mean, so these are—you talk about forces that are required to do that. Remarkable, remarkable forces that must be required to do that. 

David I mean, hurricanes and tornadoes are both huge rotating masses of air. Right? 

Victor Yeah, hurricanes are different in that they’re much, much larger than tornadoes. I mean, tornadoes, many of them are a couple hundred yards wide, okay? They last for maybe on the order of minutes, if you’re lucky. 

Hurricanes are things that last days, sometimes weeks, and they have tropical origin to them.

But at the end of the day, they’re both doing the same thing. The thunderstorm and tornado itself is an energy transfer mechanism. It’s trying to take stored, pent-up energy, heat and humidity near the surface, and transport aloft. The hurricane is trying to do the same thing. 

At the end of the day, extreme weather is just an energy transfer mechanism. And that’s—that’s the idea of climate change, right, is that these storms are getting more intense because there’s more of an energy imbalance where the temperatures are warmer, right? 

David Why is it that the United States leads the world in tornadoes? 

Victor It’s our geography. We have a north-south oriented mountain chain to our west, the Rocky Mountains—that’s generally where you’ll see a hotspot of tornado activity just downwind. They do happen other places. But U.S. is very, very unique because we have that north-south oriented mountain chain. But we also have easy access to humidity, moisture, and that’s the Gulf of Mexico. 


You know…I’ve interviewed a loooooooot of scientists over the years. And one thing I’ve noticed is that the ones who teach…are often really good explainers. Because they’ve had so much practice. 

Check out how Victor Gensini describes how tornadoes form—with analogies to common household appliances.

Victor If it’s a really, really cold summer day and you open the freezer, what happens to that air as it comes out? It comes out immediately, sinks to the ground. It’s very cold and dense.

On the other hand, hot air always wants to go up. As Victor points out,

Victor You never talk about a cold air balloon. You only talk about a hot air balloon. You get that air hot. It’s less dense, it’s buoyant. It wants to rise. 

OK, so cold air wants to sink down. Hot air wants to rise. But in the middle of the U.S., those layers start out reversed. The cold, dry air is up high, coming off of the Rocky mountains. The warm wet air is down low, coming off the Gulf of Mexico.

Victor So when you have cold air aloft and warm air at the surface, they essentially just want to trade places, right? 

If you take your index fingers and put them right in front of your nose, create some rotation that looks like it’s going forward in front of your nose. 

If you’re doing this right, your fingers are pointing toward each other, doing a sort of “Keep rolling!” motion. Oh, but P.S.— if you’re listening to this while you’re driving, keep your damn hands on the wheel.

Victor Keep that rotation going, and then point your fingers towards the ceiling. Okay, so what happens is you take that horizontal spin in front of your nose and as your fingers point towards the ceiling, it becomes spin, but now it’s along a vertical axis. And it’s that spin along the vertical axis that can create these mesocyclone, the rotation inside of these parent storms. 

David Okay, how does that log lying down, that column of air that’s lying down, rotate 90 degrees so it’s pointing up?

Victor You’ve got to have a strong updraft to push it up. So imagine again, your fingers push up that updraft, that updraft is pushing up that rotation into the vertical. 

OK. So now you know how tornadoes form, why the U.S. is the global leader in tornadoes, and how they’re different from hurricanes—tornadoes are much smaller, and they come and go in a matter of minutes. And they can do much worse damage.

Now we come to Victor Gensini’s paper, the one that generated 500 requests for interviews.

Victor The idea for the study actually just became—I was, we were, again, I mentioned I storm chase. We had a couple years in a row, I think it was like ‘12, ‘13 and ‘14, just really abysmal tornado years. I mean, very good for the people of the Great Plains, very bad for me. Very bad. 

And I was like, over the last good record that we have—have there been any spatial trends? 

And so I started just, you know, throwing numbers into spreadsheets, looking at various regions, how the trends happened in the regions. And I remember—I distinctly remember sitting at my computer and I hit Enter. I was like, “wow, that’s fascinating.” And I knew right away I was like, this has to be published immediately. I think that the next morning I started writing the paper immediately.

After the break—I’ll tell you what he discovered. Yeah, I know, that’s super manipulative, making you wait through the ad break. But hey—how much did you pay for this podcast?


Before the break, I left you tantalized and tormented by the promise that I would reveal the contents of Victor Gensini’s discovery about American tornadoes. 

Victor I think I wrote the paper and maybe three or four days with Harold Brooks. We got it submitted. And actually, funny story—the first place we went to it was the Bulletin of the American Meterological Society. We were actually rejected there. But it eventually got to the peer review literature in Nature—probably a higher-impact journal anyway. 

And what the paper said was that Tornado Alley is moving. It’s shifting to the east, from the wide open, unpopulated Plains states into the more densely populated states where a lot more people can die.

Although to be fair, Victor hates the wording I just used.

David All right. So we Americans may have heard of Tornado Alley. What is that? 

Victor It’s a term I don’t like. 

David Really! 

Victor I don’t like it, I don’t like it, it’s a media misconception, right? 

If I tell you Tornado Alley, first of all, most people are going to imagine themselves in Kansas or Oklahoma or Texas. 

The answer is, Tornado Alley is everywhere. Tornadoes happen in all 50 states, including in Alaska and Hawaii. Yes, they happen with higher frequency in Texas, and Oklahoma, and Kansas, Nebraska. 

It just, it leads people to believe that if I’m in Ohio or I’m in North Carolina, I don’t have to worry about that. Tornadoes, again, can happen any time of the year, as long as those conditions are favorable. And so, you know, I’m kind of getting away from the use of ‘Alley,’ even though there is certainly an area of the country in the central Great Plains. 

David Well, what should we call it? The ‘greater frequency zone’? 

Victor Yeah, that’s a good question. ‘The tornado high frequency zone.’ I don’t know. I don’t have a good name for it. You know, I think I’m okay with the use as long as everything that I just said is also said alongside of the use of “Tornado Alley,” so that we educate people that the alley is not just an alley that has hard bounds. 

He’s got an issue with “alley” part of “tornado alley.”

Victor First of all, what do you think of when you think of alley? You think of bowling alley, which means there’s a lane.

David When I was researching this, most of the scientifically-based maps that I saw showed, yes, a higher concentration in Texas, Oklahoma, Kansas. But it was it was not, as you say, a strip. It was like this giant amoeba. 

Victor It almost looks like—a C. The top of the C starts in like Illinois, Indiana. It arcs out towards Iowa and Nebraska. It comes down through the central plains of Texas, Oklahoma. And then it actually curves back towards Alabama and Mississippi and even portions of Georgia. So there’s it’s like a C-shape, where Missouri is kind of cut out a little bit. 

What’s interesting, though, David, is if you plot the number of tornadoes, but then plot the number of tornadoes that kill people, there is a huge dichotomy there. Tornadoes happen in the plains, but where are they killing people? Totally different. I mean, we’re talking hundreds of miles east from the greatest frequency zone where people are dying. 

David And this is where your paper comes in. Right? 

Victor Yeah, absolutely. What we’ve been seeing over the last 40 years is Kansas, Oklahoma, Texas, et cetera.—these Great Plains, the Tornado Alley, if you will, even though I hate that term—decreasing there, right, with frequency. So over the last 40 years, the number of tornadoes that we’ve seen there have actually gone down. 

And where they’ve been increasing in places like Mississippi, Alabama, Tennessee, portions of the mid-South. And in those areas, there’s lots of trees. If you have lots of trees, it’s very hard to see the incoming storm and incoming tornado. Storms there are more likely to happen at night because of their basically distance away from that north-south oriented mountain chain, right? So when they’re happening, right, it’s more likely they’re moving east into the overnight hours. 


And the reason we care about nighttime arrivals is the same reason we care about trees: If you can’t see the tornadoes coming, you’re not as prepared—and you’re more likely to die.

But wait—it gets better. Meaning worse.

Victor But probably most importantly is we have a more vulnerable population. You have a lot of people in the south, mid-south, living in a weak frame housing stock and mobile homes. I mean, some counties in the mid-south, upwards of 80, 90 percent of their infrastructure that people are living in, residential, is mobile homes. And we know if there’s one place you don’t want to be in a mobile home—or during a tornado, it’s in a mobile home or in a vehicle, okay? 

Just because of this issue, they’re more likely to produce casualties. 

David So what you confirmed is that—let me see if I phrase this right. The amorphous, roughly C-shaped amoeba of higher probability traditionally associated with the Plains states is shifting eastward into more populous, more vulnerable states. 

Victor Almost correct. I love the description, except I would not use the word shift. 

David But, but, but, but even the word ‘shift,’ though, could just mean a shift in preponderance, or a shift in likelihood. 

Victor Exactly. If you’re talking about a shift in the probability space, that’s exactly what it is. If you’re talking about a geographic location shift, that’s where the issue comes in. 

We don’t want to tell people in Oklahoma and Texas they don’t worry about it, it’s shifting. What we really want to highlight is this increasing threat from tornadoes, greater frequency, greater number—happening in the mid-south, where we know people are already extremely vulnerable due to socioeconomic issues. 

David Okay, so—in Tornado Alley, still the most tornadoes, still a lot of tornadoes. 

Victor Yes. 

David And farther east, an increasing number of tornadoes. 

Victor Exactly. Exactly. 

David And why?

Victor It’s very likely to me that it’s a component of the actual input into the atmosphere from humans. So anthropogenic climate change, in addition to some degree of natural variability. 

Victor It’s very consistent with what our climate models show as we get into later this century, where the Great Plains, specifically Texas, Oklahoma, begin to dry out and become basically these big heat domes, hot heat domes, that don’t produce a lot of severe weather. 


And so, in October 2018, Victor’s paper appeared in the journal Nature. It raised a lot of eyebrows, and dropped a lot of jaws.

Victor The, the trends study obviously garnered a lot of public attention. A lot of the Associated Press, a lot of the news articles were like, ‘Tornado Alley is shifting, ahhh!’ Right, and everyone was up in arms, and I had like 500 media requests overnight. 

I mean, there’s lots and lots of issues and caveats, as there are with almost any scientific study. So it’s, it’s my—I felt it as the lead author, I sort of took it upon myself that, you know, I’m going to do as many of these interviews as I can. I want to sort of set the record straight in terms of what we know and what we don’t know about things like tornadoes, tornadoes and climate change. 

David Okay, so—is real life bearing out what you said? Are Tennessee and Mississippi, are they seeing more damage, more loss of life? 

Victor Absolutely. I mean, if you look at the data from ‘19-’20, and then the preliminary data so far from ‘21, very active in the southeastern United States. 

After we published that study, for example the Nashville tornado occurred. I don’t know if you remember that event as well. 

I do remember it. It was March 2020.

[News clip montage]

BRANDIS We heard the wind and got the alarms on our phones. And we just sprinted out of the building. So running down the hallway, the ceiling was just caving in, debris everywhere, and water is pouring from the ceiling, like waterfalls in the hallway. 

GUY The whole back of the roof was caved in, the front of it caved in, we have no front porch, and all the houses down our street are completely gone.

NEWS If you look in the distance, that is the cone, or the V of the tornado as it was actually touched down in Nashville. This is a massive, massive funnel on the ground right there. You can see just how big that is, which is why we’re seeing this type of damage over a wide area.

In the end, the Nashville tornado killed 25 people and cost $1.6 billion in damage—the sixth costliest tornado in U.S. history. And it was hundreds of miles east of the traditional Tornado Alley.

Victor So there are a lot—I hate to cherry pick just Nashville, but there are events that have continued to occur and will continue to occur in the southeastern United States. 

Victor says that the climate crisis isn’t the only reason the death and destruction are getting worse. We also keep building in Nature’s way.

Victor So I think part of the, really the, the, the drive-home point is that there is a huge expanding human footprint that these hazards are hitting. We’re looking around going, holy shit, the world’s on fire. We’re having all these disasters. We have wildfires in the news. Tornadoes, hail, hurricanes. We just saw a massive heat wave in the west. That was well beyond anything we’ve ever recorded. We’re very certain that climate change had some component, some piece to that. 

But—what does this other piece of us just having so many more assets, so many more things to hit, these extreme weather disaster—by these extreme weather events, and how much is that contributing to the overall picture of economic loss not only in the U.S., but in the world? 

David Well, are there any positive trends in the way people are building and living in these increasingly vulnerable areas? 

Victor I haven’t seen anything. In fact, it seems after these disasters occur, we simply go back and build half-assed construction with very, very little oversight. You know, like, what? 

Building codes and structures, unfortunately, right, those are set at the local level. And so there’s no federal mandate, right, of “Oh, you live in Oklahoma City, you have to have a tornado or a house that can withstand an F3 tornado.” None of that exists in the United States, right? 

And yet that costs money. I get it. But it’s a long term investment, okay? Would you rather be paying for the disaster in 25 years, or put up the money up front, and invest in a more resilient infrastructure that’s going to be less prone to these types of events in the future? 

David I mean, we as a species have never been great at anticipating—like, we still smoke, we still don’t exercise. I mean, we know, right? We still don’t really take climate change seriously. I mean, we should have started 40 years ago. 

Victor Yes, I have—I would not argue with that. I think it’s—where, when do you get to the point? What is the level of disaster that has to occur in order for us to go—Yep, okay, we need to do something now, versus, you know, Oh, we just had another six standard deviation anomaly heat wave in the Pacific Northwest. And British Columbia is on fire, literally on fire right now. What do you do, you know? 

And, as usual in the world of climate chaos, people without a lot of money get hit first and worst.

Victor The people that are going to be most impacted by places—like, by most of the impacts of climate change—drought, flooding, sea level rise are going to be areas that are very, very socioeconomically disadvantaged. When, as a species, do we make that critical call of like, “Okay, we’re serious now. We weren’t before, but we’re serious now.” And is when that happens, is it too late? 

OK. So now you know that what’s traditionally known as Tornado Alley is shifting—or maybe I should say growing—into the more vulnerable, more populous states to the East. And that tornadoes form super fast; they’re not like hurricanes, where we see it coming a week before it hits. OK. So what are you supposed to do?

Well, about an hour before the tornado, your phone, or the radio or TV, might announce a tornado watch. That’s when the conditions are perfect for tornadoes to form, but nobody’s seen one yet.

A tornado warning means that somebody’s actually spotted one. 

Victor For most people, it’s as simple as get to the lowest floor in your home. If you don’t have a basement, that’s okay. Just get to the lowest floor and put as many walls between you in the tornado as possible. That’s it. So if that’s an interior closet, great, that’s a bathroom, great, if it’s underneath stairs, great, just get to the lowest floor. That will give you a very, very high likelihood of surviving even a strong tornado if you take that. 

The other thing that we tell people is that it’s not a bad idea to have a bicycle helmet in there. Most of the casualties we see are blunt force trauma to the head. So what a better move than just putting a bike helmet on, you know, and crouching down into your—

David Wow! 

Victor Yeah, yeah. In your severe weather safety kit, whether it’s water, batteries, flashlight—bike helmets are cheap, pick up a bike helmet and put a bike helmet on. That way, you have some sort of cushion between you and the flying debris. 

And Victor has special advice if you live in a mobile home. 

Victor Well, if you’re in a mobile home, don’t wait for the warning to be issued. You should be taking action at the watch stage, when the conditions are favorable, right? 

Many times, you’re lucky to get 10 or 15 minutes lead time when these events occur. 

You know, and I understand not everybody has the access or the means to just pick up and go somewhere. But there are community shelters in many places. You could perhaps go to a neighbor’s house or somebody that has, you know, a sturdier structure. But you don’t want to be in a mobile home during a tornado and you don’t want to be in a vehicle. Those are two areas you got to sort of figure it out. 

David So you—you have completed your storm chasing season for 2021, right? 

Victor Yes. We’re kind of all getting back. We’re getting unpacked, finally starting to sort through our pictures. And then by about Christmas, we, something sets in called SDS, or Supercell Deprivation Syndrome, where we start planning our trip, right, for next year. 

And so our pilgrimage again, you know, begins. 

You know what? I’m starting to get the impression that Victor Gensini really loves tornadoes.

Victor It’s like this giant orchestra, right, that’s playing. And every instrument has a role. And you’ve got to figure out what’s the moisture doing, what’s this doing? What’s the shear? I mean, there’s so many moving parts that, you know, just understanding the percussion is not enough. You got to understand the ensemble. And that’s what makes this problem so challenging. 

David Well, if it were up to me, I would suggest that you look at mid-levels for rotation and increase the PRF. 

Victor I love it.