Cosmic Queries: Tour of the Solar System

In this Cosmic Queries episode, Neil deGrasse Tyson answers fan questions about exploring the solar system, the possibility of life on Europa and black holes.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:01Neil deGrasse Tyson?

  Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.

• 0:21Neil deGrasse Tyson?

  I'm your host, Neil deGrasse Tyson, your personal astrophysicist, and this is StarTalk.

• 0:31Neil deGrasse Tyson?

  Chuck, nice. Chuck, welcome back to the show.

• 0:33Speaker 01

  Hey, man. Thanks for having me back, Neil.

• 0:35Neil deGrasse Tyson?

  I will not soon forget the Super Bowl show, the football show. You were on fire.

• 0:40Speaker 01

  Dude, that was great fun.

• 0:41Neil deGrasse Tyson?

  You were out of control.

• 0:42Speaker 01

  That was great fun, man. Ready to get back into it today and get high on science.

• 0:49Neil deGrasse Tyson?

  We're gonna get really high on science. Today's show is a tour of the solar system.

• 0:54Speaker 01

  Sweet.

• 0:54Neil deGrasse Tyson?

  A tour of the solar system. I think every now and then you gotta take a tour of your backyard.

• 0:58Speaker 01

  Fantastic.

• 0:59Neil deGrasse Tyson?

  That's what you gotta do.

• 1:00Speaker 01

  Will you be our tour guide?

• 1:01Neil deGrasse Tyson?

  I will be your tour guide, but I have some help from two very competent colleagues of mine. One of them, Steve Squires. He's the scientist behind the Mars rovers.

• 1:09Speaker 01

  Wow.

• 1:10Neil deGrasse Tyson?

  You know, we all read about the rovers and he saw pictures of the terrain. He's in charge.

• 1:15Speaker 01

  And?

• 1:16Neil deGrasse Tyson?

  These are his babies.

• 1:17Speaker 01

  Did they blame him when they broke down?

• 1:20Neil deGrasse Tyson?

  No, they blame him when they save. You know, these things should have broken down long ago.

• 1:24Speaker 01

  Oh, really?

• 1:25Neil deGrasse Tyson?

  Way long ago. So he's been saving them. He's their savior, as it were.

• 1:29Speaker 01

  Fantastic.

• 1:30Neil deGrasse Tyson?

  We're also will be hearing from Heidi Hammel. She's your research scientist at the Space Sciences Institute in Boulder, Colorado.

• 1:35Speaker 01

  Oh, cool.

• 1:36Neil deGrasse Tyson?

  Colorado, yeah. Yeah, so that should be fun. But you know, you know who's a friend of StarTalk Radio?

• 1:41Speaker 01

  Ah, I do know.

• 1:43Neil deGrasse Tyson?

  Bill Nye.

• 1:43Speaker 01

  Bill Nye, the science guy.

• 1:45Neil deGrasse Tyson?

  So were you influenced by him when you were a kid?

• 1:48Speaker 01

  Absolutely, absolutely. And by kid, if you mean 20, yes.

• 1:55Neil deGrasse Tyson?

  So I got ahold of Bill Nye. By the way, lately, he's the executive director of the Planetary Society. He finally has like a real job, you know?

• 2:03Speaker 01

  Oh, really?

• 2:03Neil deGrasse Tyson?

  It's like he gets a paycheck and everything.

• 2:05Speaker 01

  You know, honestly, I always wonder, what else does he do?

• 2:08Neil deGrasse Tyson?

  What does he do?

• 2:09Speaker 01

  Except show up on TV and talk to kids?

• 2:11Neil deGrasse Tyson?

  Exactly. No, no, he's actually talking to grownups now, including Congress.

• 2:14Speaker 01

  Okay.

• 2:15Neil deGrasse Tyson?

  So he's gonna start us off and give us, put us in a good way, getting us to think about where we are in the solar system and where we might one day go.

• 2:26Speaker 02

  The most recognizable image to anyone on Earth is the Earth as seen from space. When you look above you at night these days, I hope you notice occasional very bright objects among the stars, other planets. Humans have spent centuries trying to know all about them. By exploring the solar system, first with our eyes, then telescopes, and these days with extraordinary spacecraft, we have come to know that Mars is cold, Venus is hellishly hot, Saturn would float if it could, and our Earth is but one world among thousands of objects whirling about a common star. Between and beyond the planets are all manner of objects: comets, moons, asteroids, distant icy plutoids, and dust. Often as a young scientist, I'd be given a textbook with a place to write my name inside

• 3:11Speaker 02

  the cover, below that, my street, my city and state. But I'd go on: United States, North American continent, Earth and Sun. Because we've explored our solar system, I could have added the third rocky ball from the medium-sized star. Have a look around. Your life is changed every day by explorers who've pondered our place in space. For StarTalk Radio, I'm Bill Nye the Science Guy.

• 3:36Neil deGrasse Tyson?

  That's my boy, Bill Nye.

• 3:37Speaker 01

  Nice. Okay, I just gotta ask you that.

• 3:40Neil deGrasse Tyson?

  What's that?

• 3:41Speaker 01

  Plutoids?

• 3:42Neil deGrasse Tyson?

  Plutoids.

• 3:43Speaker 01

  Is that like a cosmic mint?

• 3:44Neil deGrasse Tyson?

  Plutoids.

• 3:45Speaker 01

  A plutoid?

• 3:46Neil deGrasse Tyson?

  What a, that's a great, a great product name there, right there. We should start that up. But what would your breath smell like? That's the question.

• 3:53Speaker 01

  Hopefully not cosmic dust.

• 3:55Neil deGrasse Tyson?

  It's cosmic, yeah, you know, gotta watch out what stuff smells like out there.

• 3:58Speaker 01

  Plutoids.

• 3:59Neil deGrasse Tyson?

  So the solar system, its formation was four and a half billion years ago from a huge giant gas cloud, and right in the middle of that gas cloud, where it's densest and hottest, that's where you get the Sun. And that's what forms first, and then you get planets and other stuff forming around it. It was a day when if you learned about the solar system, it would be like an enumeration of the planets one after another. But, excuse me, the solar system is so much more than that. From the moons around planets, to the dust in the plane of the solar system, to asteroids, some of which hit the Earth, comets. It's a very rich, dynamic place. And in case you really wanna geek out on the Sun, the Sun has an actual official classification code.

• 4:40Speaker 01

  Okay.

• 4:41Neil deGrasse Tyson?

  It's a G, capital letter G.

• 4:43Speaker 01

  Right.

• 4:44Neil deGrasse Tyson?

  Arabic numeral two.

• 4:46Speaker 01

  Okay.

• 4:46Neil deGrasse Tyson?

  Roman numeral five.

• 4:49Speaker 01

  So G two five.

• 4:50Neil deGrasse Tyson?

  Yes.

• 4:51Speaker 01

  In three different, uh, languages and letters and alphabets and number systems.

• 4:56Neil deGrasse Tyson?

  Each one means something different.

• 4:57Speaker 01

  Means something different.

• 4:58Neil deGrasse Tyson?

  Yeah, she wanna geek out on the sun. That's what it would, that's what it is.

• 5:00Speaker 01

  Now, why G two five? Cause that really, I don't get it.

• 5:03Neil deGrasse Tyson?

  Okay, so G.

• 5:03Speaker 01

  G two five.

• 5:04Neil deGrasse Tyson?

  G tells you what the temperature is, okay?

• 5:06Speaker 01

  Which is a gazillion degrees.

• 5:08Neil deGrasse Tyson?

  That's what G stands for.

• 5:09Speaker 01

  Really, that's it?

• 5:12Speaker 01

  For a moment, I almost felt smart. I was like, I got it right.

• 5:16Neil deGrasse Tyson?

  So, the stars in order of decreasing, uh, temperatures, O B A F G K M. So, the sun is one of the cooler of the stars.

• 5:23Speaker 01

  Oh, yeah. You know it is, baby, cause it's here in our solar system.

• 5:26Neil deGrasse Tyson?

  It's cool, but it's actually white hot. And the sun is often portrayed as yellow, but it's actually white. Just go outside and look. It's white. In broad daylight, it's white.

• 5:35Speaker 01

  Right.

• 5:35Neil deGrasse Tyson?

  What happens when it gets low on the horizon, then you can look at it without burning out your eyes. Hey, look, the sun is yellow orange, cause the atmosphere has changed its color.

• 5:43Speaker 01

  So, those are particles in our atmosphere that actually change the color.

• 5:46Neil deGrasse Tyson?

  That actually, what the particles do is scatter the blue light out of the rainbow, leaving behind the red and the orange.

• 5:51Speaker 01

  So, basically, if you were in space, you would look at the sun.

• 5:55Neil deGrasse Tyson?

  And be white no matter what angle.

• 5:56Speaker 01

  Be white no matter what.

• 5:57Neil deGrasse Tyson?

  No matter how you put your head.

• 5:58Speaker 01

  Burn your eyes out and that'd be the end of it.

• 5:59Neil deGrasse Tyson?

  That'd be the end. The last experiment you did. So, what I've got is, let's go to my, let's go to my colleagues. Uh, they've visited me in New York, in my office, Steve Squires, Principal Investigator of the Mars Rovers, Professor of Astronomy at Cornell University, and Heidi Hammel, who is, who is total planet babe. This is, she's all about planets.

• 6:19Speaker 01

  Sweet.

• 6:19Neil deGrasse Tyson?

  And so, let's find out what we all have to talk about.

• 6:24Neil deGrasse Tyson?

  So, Steve, I keep thinking of you as like Mr. Mars. Anytime I look up in the sky and Mars is there, I'm thinking of your two rovers there. When you look up at Mars in the night sky, is that what, do you think that too?

• 6:33Speaker 03

  You know, Mars.

• 6:34Neil deGrasse Tyson?

  Would you just wish you were there?

• 6:35Speaker 03

  Mars looks different to me than it used to. It used to be, I I can remember before we launched them, looking at Mars in the night sky and it just looked impossibly far away.

• 6:46Neil deGrasse Tyson?

  So now it's your backyard.

• 6:47Speaker 03

  And I look at it now and I think I know this place.

• 6:49Neil deGrasse Tyson?

  You're a kid playing in your backyard.

• 6:51Speaker 04

  It's a sandbox.

• 6:52Speaker 03

  Yeah. It it just to- it feels totally different to to to look at Mars now than it did a long time ago, yeah.

• 6:57Speaker 04

  Do you see it, though, do you, when you see it in the sky, do the pictures from the rovers, is that what you see?

• 7:03Speaker 03

  Ah, kind of, except I don't think in terms of pictures. I I sort of feel like I know what would it, what it would be like to be there. You know, not just the pictures of the surface, but I know what the clouds in the sky look like. I know the seasons.

• 7:15Neil deGrasse Tyson?

  The rovers are his avatar.

• 7:17Speaker 03

  It's kind of feels like that, yeah, it does. And I I, we've experienced Mars through those rovers for so long. I I kind of feel like I know what the place is like now.

• 7:26Neil deGrasse Tyson?

  Yeah, but are you now sort of, do you have Mars on the brain so that you, it's hard to think about the rest of the solar system?

• 7:31Speaker 03

  No.

• 7:32Neil deGrasse Tyson?

  Heidi, Heidi, you get around the solar system, right?

• 7:34Speaker 04

  I should do, yeah, I look at a lot of other planets besides just Mars.

• 7:37Neil deGrasse Tyson?

  So you're not just-

• 7:37Speaker 04

  We don't have that, we don't have those images, we don't have those rovers on the surface, so I still think a lot in pictures.

• 7:43Neil deGrasse Tyson?

  Plus, half your planets don't have surfaces.

• 7:44Speaker 04

  Well, that's true, yeah, they've got, but they've got-

• 7:47Neil deGrasse Tyson?

  I have to ask, what's your favorite?

• 7:48Speaker 04

  You know, it changes with time.

• 7:50Neil deGrasse Tyson?

  Ah, it's just like picking your children, right?

• 7:52Speaker 04

  Yeah, exactly, I don't, you don't play favorites.

• 7:55Neil deGrasse Tyson?

  Uh huh.

• 7:56Speaker 04

  You know, at different times, different planets do different things.

• 7:59Neil deGrasse Tyson?

  Mm-hmm.

• 7:59Speaker 04

  And so if you were looking at, you know, Uranus at equinox and it's busted out with clouds-

• 8:04Neil deGrasse Tyson?

  And that's the official, it's not Uranus, right, it's Uranus.

• 8:07Speaker 04

  Yeah, you know, I kind of gave up on that whole thing.

• 8:10Speaker 04

  I gave up on that, you know, for a while I was on a mission to educate people about Uranus. And then my own hometown paper wrote a story about those yellow lights, you know, that they were trying for, to cost efficiency. And the headline in my-

• 8:24Neil deGrasse Tyson?

  Oh, for the nighttime, for the streetlights?

• 8:25Speaker 04

  Yeah, yeah, yeah, for the streetlights, right, streetlights at the night, so that it would be darker, um, less light pollution. And and some people didn't like it, and they ran a headline about the Uranus-colored light. And that's when I gave up. Yeah, I would call it Uranus, um, that's more traditional. But, you know, when Voyager flew by Uranus in nineteen eighty-six, it was dead. There was like maybe ten clouds, if you really stretched the contrast to the atmosphere.

• 8:51Neil deGrasse Tyson?

  So Uranus is a big ball of gas with no surface features.

• 8:52Speaker 04

  Basically, yeah, I mean, that's right. If you and I were on a spaceship outside it- When Voyager flew by, when Voyager flew by, didn't see anything. And so everyone thought it's a dull and boring. Well, that's not what it's like right now. It's in a completely different season. And the atmosphere is turning on, and there's bright clouds, and there's dark spots, and there's all kinds of activity on this planet. And this is my favorite right now, because flies in the face of what we were taught in school about Uranus, you know, we were taught that-

• 9:18Neil deGrasse Tyson?

  I remember the books. It's, it, Uranus was an example of a boring-

• 9:22Speaker 03

  It's the boring one, yeah.

• 9:23Speaker 04

  That's right, which is just absolutely not true right now. And the books are starting to finally catch up with reality.

• 9:29Neil deGrasse Tyson?

  Now, Mars, of course, is a dynamic place.

• 9:31Speaker 03

  Yeah, it's changing all the time. I mean, it's got seasons, very much like the Earth does, uh, very different at different times of year, it's-

• 9:37Neil deGrasse Tyson?

  It's not only very much like, it's like, almost exactly like the Earth does, right? I mean, it's tipped how many-

• 9:41Speaker 03

  Twenty-five to-

• 9:42Neil deGrasse Tyson?

  Twenty-five, and we're twenty-three.

• 9:43Speaker 03

  Twenty-three and a half, yeah. So it's, it's almost the same, the year is longer, of course.

• 9:47Neil deGrasse Tyson?

  Rotates once, rotates once in how many-

• 9:48Speaker 03

  Twenty-four hours and thirty-nine minutes. And let me tell you, if you're operating rovers on Mars, that just plays havoc with your life.

• 9:55Neil deGrasse Tyson?

  Okay, next time that happens to me, I'll keep that in mind.

• 9:57Speaker 03

  Uh, you know, you would think it'd be-

• 9:59Neil deGrasse Tyson?

  Listeners, when you're operating rovers, just, just get, get ready for this-

• 10:02Speaker 03

  You know, you would think it'd be nice to be able to sleep in an extra thirty-nine minutes each day, but it, it, it kind of adds up in weird ways.

• 10:08Speaker 04

  Gets out of sync, doesn't it?

• 10:09Speaker 03

  It gets out of sync.

• 10:09Neil deGrasse Tyson?

  Oh, you think it's like, uh, in, a slow jet lag that heats away at you?

• 10:13Speaker 03

  We lived on Mars time for months. We had Mars alarm clocks, Mars stopwatches, uh, we had food service on Mars time, maid service in our apartment on Mars time, we had blackout curtains on the windows, so you couldn't tell if it was daytime or nighttime, or it was like being in a casino.

• 10:29Speaker 04

  But did you adjust, or did you adjust to it, or did you really feel human and terrestrial? Because your bodies couldn't adjust to it.

• 10:34Speaker 03

  Our bodies could adjust to it just fine, as long as Earth did not interfere in our lives.

• 10:39Speaker 04

  In other words, the blinds on the windows were absolutely-

• 10:42Speaker 03

  That was fine, and if you have to live a day that's twenty-four, thirty-nine, it's perfectly easy to lead, unless you have to interact with real human beings in the real world on Earth.

• 10:52Neil deGrasse Tyson?

  So, you were basic-

• 10:53Speaker 04

  Like a spouse.

• 10:53Neil deGrasse Tyson?

  Like a spouse, or you walk your dog or something, that sort of thing. So, what you're saying is you were basically in a Mars habitat here on Earth?

• 11:00Speaker 03

  Yeah, we kind, we kind of were, but then there would be events, you know, somebody would decide there had to be a meeting at eight o'clock in the morning, Pacific time. And if it's in the middle of my night, I was still expected to show up. And that was when it got difficult.

• 11:11Neil deGrasse Tyson?

  Wait, I thought you were in charge.

• 11:13Speaker 03

  Not when it came to interacting with the press. When we had press conferences, they were at 8 a.m. Pacific and that was it. And, uh, yeah, that telling CNN that we want to have our press conference at 3 a.m. just didn't work real well.

• 11:25Neil deGrasse Tyson?

  So the press likes, likes, likes your rovers?

• 11:28Speaker 03

  I think they do.

• 11:30Speaker 01

  Wow.

• 11:31Neil deGrasse Tyson?

  Geekin' out on the planets.

• 11:32Speaker 01

  Dude, that was like Geek-a-palooza.

• 11:34Neil deGrasse Tyson?

  Geek-a-palooza. Isn't it great? Everybody has a favorite planet. You know, how many people in the street, you know, just, well, this is my favorite planet for these 11 reasons.

• 11:41Speaker 01

  Yeah, well, most people you ask, what's your favorite planet? They're gonna be like, the one I'm standing on.

• 11:46Neil deGrasse Tyson?

  Not the one, well, this one used to have no surface features and then cloud layer. There's a whole analysis of what they follow and why and, and it keeps them pumped every single day.

• 11:55Speaker 01

  Yeah, I'm just, I'm just glad to know that Mars has seasons.

• 11:58Neil deGrasse Tyson?

  Yes, yes, and polar ice caps. This, this accounts for its allure in the history of science fiction writing. Why people have chosen Mars as a target for life, more so than other planets.

• 12:08Speaker 01

  Oh darling, I can't wait until we take spring in Mars.

• 12:13Neil deGrasse Tyson?

  Not only that, what, what we have on Mars is not only the rovers, they're orbiters as well. So that we can know where we might send the rovers next. Otherwise, you're kind of driving blind. And what's good about rovers is it's a mobile geologist and you don't have to go there. Plus, the rover doesn't have to come back. So if you send a human being, they probably, they usually want to come back.

• 12:31Speaker 01

  Normally.

• 12:32Neil deGrasse Tyson?

  You gotta feed them, you know?

• 12:34Speaker 01

  You gotta send a misanthrope. I hate you guys.

• 12:37Neil deGrasse Tyson?

  Yeah, yeah, get, get a holler, go to Mars. So one of the things we found recently in Mars is methane emanating from the sides of ravines in Mars.

• 12:46Speaker 01

  Really?

• 12:47Neil deGrasse Tyson?

  Yeah, and methane is the kind of gas that is produced within the anaerobic digestion of food.

• 12:52Speaker 01

  Okay, so actually Mars is a big giant fart, is what you're saying.

• 12:58Neil deGrasse Tyson?

  Did I say, did I?

• 12:59Speaker 01

  I did.

• 13:01Speaker 01

  You know, that's.

• 13:01Neil deGrasse Tyson?

  Chuck, that's why we have you on the show.

• 13:02Speaker 01

  That actually sounds more like Uranus. Or, or should I say Uranus?

• 13:07Neil deGrasse Tyson?

  No, Uranus, yes, we just got schooled on that one.

• 13:11Speaker 01

  Uranus, that's what it, Uranus.

• 13:12Neil deGrasse Tyson?

  So, uh, after the break, we'll talk about the search for life and how the search for water is driving the search for life. Cause everywhere on Earth where you find liquid water, you find life, every. place, including places like the Dead Sea. The reason why they called the Dead Sea? They didn't have a microscope to tell what would do the backstroke in the

• 13:30Speaker 01

  But there are, there are things alive in the Dead Sea.

• 13:32Neil deGrasse Tyson?

  Not fishes, but there's other stuff that's alive for sure.

• 13:35Speaker 01

  Right.

• 13:36Neil deGrasse Tyson?

  And you are listening to StarTalk Radio. Follow us at StarTalkRadio.net. We are on Facebook, StarTalk Radio, and we tweet at, guess what Chuck? StarTalk Radio.

• 13:46Speaker 01

  At StarTalk Radio.

• 13:48Neil deGrasse Tyson?

  And I tweet the universe at Neil Tyson and Chuck Nice, you are

• 13:52Speaker 01

  At Nice Chuck Nice.

• 13:54Neil deGrasse Tyson?

  Who said you were nice?

• 13:54Speaker 01

  It certainly was me. Cause nobody else is saying that.

• 13:58Neil deGrasse Tyson?

  Nobody else is saying that, for sure.

• 14:00Speaker 01

  I keep trying to convince people.

• 14:03Neil deGrasse Tyson?

  You're listening to StarTalk. Stay tuned for another segment.

• 14:20Neil deGrasse Tyson?

  Welcome back to StarTalk. Here's more of this week's episode.

• 14:27Neil deGrasse Tyson?

  And we're talking about the solar system today, a tour of the solar system, basically. We have two of the world's experts to serve that up. One is Steve Squires, who runs the Mars Rovers, which we've all heard about. Everyone's heard about the Rovers, even if you didn't know he was the man in charge. And there's a whole team, of course, but he's the, he's, he's the main

• 14:43Speaker 01

  He's the top banana.

• 14:43Neil deGrasse Tyson?

  Top banana.

• 14:44Speaker 01

  There you go.

• 14:44Neil deGrasse Tyson?

  And Heidi Hammel, who's an all-around planet geekess. I mean, is that the word geek?

• 14:50Speaker 01

  Geekess. I like, you just made it up. I like it.

• 14:52Neil deGrasse Tyson?

  We make it right on the spot. And, and so the solar system is full of a lot of sort of alien worlds. There are moons and planets and comets and asteroids and, and one planet is different from the next, one moon is different from the next.

• 15:06Speaker 01

  Right.

• 15:06Neil deGrasse Tyson?

  These are, these are exotic places.

• 15:08Speaker 01

  Yes.

• 15:09Neil deGrasse Tyson?

  Is any place you, one of these you might want to visit one day?

• 15:11Speaker 01

  Pandora. I just love those blue people. They're so adorable with their little tails and I love them.

• 15:20Neil deGrasse Tyson?

  And they're so, they're so nimble on tree limbs.

• 15:22Speaker 01

  Exactly.

• 15:24Neil deGrasse Tyson?

  You worry about me sometimes. You know, because there's so much going on in the solar system, not everything has a perfectly circular orbit around the sun. A circular orbit is the only orbit you can have and not hit something else, okay?

• 15:37Speaker 01

  Okay.

• 15:37Neil deGrasse Tyson?

  If you do not have a circular orbit, there's a chance you're gonna get hit, you're gonna hit something, something's gonna hit you.

• 15:42Speaker 01

  Now, from what I understand, aren't there planets here in our solar system that have an elliptical orbit?

• 15:48Neil deGrasse Tyson?

  Yes, uh, uh, no, not anymore.

• 15:50Speaker 01

  No.

• 15:52Neil deGrasse Tyson?

  Pluto, don't get me started on Pluto, take it outside.

• 15:57Neil deGrasse Tyson?

  Let's go, let's go back to Steve Squiers and Heidi Hammel, they're gonna tell us how, what kind of a shooting gallery the solar system actually is. Now Heidi, you go way back with the press, my first encounters with you, as I think with many, were with the comet impact on Jupiter. You were like the face of the comet.

• 16:12Speaker 04

  The first, the first impact on Jupiter.

• 16:14Neil deGrasse Tyson?

  Yeah, there's more than one?

• 16:15Speaker 04

  We just had another one in July.

• 16:16Neil deGrasse Tyson?

  Oh, I know about that, I forgot all about that. I've just, I've been busy, I'm sorry, I'm sorry, okay?

• 16:21Speaker 04

  It's an impact, it's, you know, it's the size of the earth kind of thing, it's an explosion.

• 16:25Neil deGrasse Tyson?

  So Jupiter's kinda asking for it, right?

• 16:27Speaker 04

  Yeah, well, yeah.

• 16:28Speaker 03

  Well, it's a big target.

• 16:29Speaker 04

  Well, it's there to take one on the chin for us, you know?

• 16:31Speaker 01

  It's a big target.

• 16:32Neil deGrasse Tyson?

  That's really true, really true, it's protecting us, it's our big brother protecting us.

• 16:36Speaker 04

  Yeah, but yeah, my first interactions with the press on any large scale were back in 94 when we were doing weather broadcasting from Jupiter.

• 16:44Neil deGrasse Tyson?

  What, so what, what was going on every day on Jupiter?

• 16:47Speaker 04

  Absolutely, it was pretty exciting stuff.

• 16:49Neil deGrasse Tyson?

  Yeah, so if that happens just in the last couple of decades, this must be going on all the time, right?

• 16:54Speaker 04

  I would think so.

• 16:55Neil deGrasse Tyson?

  Living in some special time when Jupiter's getting hit.

• 16:57Speaker 04

  We thought we might have been lucky the first time, and when it happened just exactly 15 years later, we realized, hmm, maybe we aren't so lucky.

• 17:04Speaker 03

  All right, now, here's a question, now that you know what to look for, now that you know what an impact on Jupiter looks like, is there data mining you can do? Can you go back to old pictures?

• 17:12Neil deGrasse Tyson?

  Data mining, so it's like looking back in an old...

• 17:14Speaker 04

  Even after the 94 impact, some folks went and did do that, they went back and looked, we had the planetary patrol telescopes, I don't know if you're aware of that? Network of 24-inch telescopes that were just studying Jupiter, you know?

• 17:26Neil deGrasse Tyson?

  Creating an archive of data.

• 17:27Speaker 04

  Exactly, and there's nothing like Shoemaker-Levy 9, you know, the big one that 94 was there.

• 17:32Speaker 03

  So you would have seen it, the pictures are good enough that you'd know.

• 17:34Speaker 04

  Absolutely, that's right, and people, you know, do talk about the historical record, there's reports of Cassini himself, not Cassini the spacecraft, but Mr. Cassini. Cassini the guy. Cassini the guy, who did these drawings.

• 17:45Neil deGrasse Tyson?

  It's weird to think there are people with names after spacecraft. What a coincidence.

• 17:49Speaker 04

  When you say Galileo, you know, we're talking about Galilei, the guy, or Galileo, the spacecraft. Cassini drew pictures of.

• 17:54Neil deGrasse Tyson?

  Or the European Navigation System, Galileo.

• 17:56Speaker 04

  That's right.

• 17:57Neil deGrasse Tyson?

  Their counterpart to our GPS.

• 17:58Speaker 04

  You gotta get some more astronomers' names in play, like, you know, Neil deGrasse Tyson.

• 18:05Speaker 04

  Yeah, name, mission, name, and after you.

• 18:06Speaker 03

  You have to die.

• 18:07Neil deGrasse Tyson?

  Yeah, yeah. That's right, these are named after dead people, yes, okay.

• 18:11Speaker 04

  But people did go back and look, and they haven't seen conclusive evidence in the past of any big events like this. But I'll tell you, nowadays, these amateurs have terrific telescopes, they have amazing CCD systems.

• 18:24Neil deGrasse Tyson?

  Allow me to clarify, in most professions, if you accuse them of being an amateur, it would be an insult. Whereas in astronomy, amateur is a badge of pride and courage.

• 18:32Speaker 04

  Well, and also, they do terrific science now. There's synergy between the professional astronomy community that basically has the really huge telescopes. And the amateurs who have smaller telescopes, but they're terrific, and they have tons of time. Because the amateur just goes out at night and spends all night looking, whereas.

• 18:50Neil deGrasse Tyson?

  And they're in every time zone.

• 18:51Speaker 04

  Every time zone, all around the world. With these big telescopes like Hubble or the Keck ten meter, you might get half an hour a year. And that's all the time you have to look at your objects. So they rely on the amateur community to feed us information about things like impacts on Jupiter. It was an amateur who spotted that and alerted the professional community.

• 19:12Neil deGrasse Tyson?

  This later, the second impact, yeah.

• 19:13Speaker 04

  The second one, that's right.

• 19:15Neil deGrasse Tyson?

  So I'm sitting between two very different kinds of scientists now. One who, you, Heidi, who are still using telescopes.

• 19:22Speaker 03

  She's kind of behind the times.

• 19:25Speaker 04

  No, I'm looking at things that are far away.

• 19:27Neil deGrasse Tyson?

  You're still looking at them, and Steve, you're just there, you know? You don't worry about the optics, you don't worry about bad weather, you're just there.

• 19:35Speaker 03

  Oh, we worry about both of those, my friend. First of all, we got optics all over these rovers. Second, we are very, very sensitive to the weather on Mars.

• 19:43Neil deGrasse Tyson?

  Okay.

• 19:43Speaker 04

  But it is true that he can send spacecraft to his object and get them there within, you know, a reasonable funding cycle.

• 19:51Neil deGrasse Tyson?

  Before he dies.

• 19:52Speaker 04

  Before he dies.

• 19:52Neil deGrasse Tyson?

  Yeah.

• 19:53Speaker 04

  If we want to start talking about planets around other stars.

• 19:57Neil deGrasse Tyson?

  Yeah.

• 19:57Speaker 04

  We aren't gonna be sending spacecraft.

• 19:59Speaker 03

  Or even, even some of the, uh, you know, some of the, the planets in the outer solar system, if you're talking about a Neptune, uh, a mission to Neptune, the time scales for pulling that off are very long.

• 20:08Neil deGrasse Tyson?

  Well, so that's why the Pluto mission, the New Horizons, that's on, there was like a light payload with some really huge engines.

• 20:14Speaker 04

  Right.

• 20:15Neil deGrasse Tyson?

  To get it there.

• 20:15Speaker 04

  That's right, yeah.

• 20:16Neil deGrasse Tyson?

  Yeah, yeah, that one was, that, that was booking.

• 20:18Speaker 04

  And it's still on its way and we got years to go.

• 20:20Neil deGrasse Tyson?

  Yeah. Another five years. So it's, it's humans attack the solar system. That's what this is about, Chuck.

• 20:26Speaker 01

  That's, I've learned some things, man.

• 20:27Neil deGrasse Tyson?

  Well, this is what, we're, this is at the point of the show.

• 20:29Speaker 01

  The, the thing I learned, uh, that most stuck out was that in astronomy, size matters.

• 20:34Neil deGrasse Tyson?

  Yes, it does.

• 20:36Speaker 01

  Everybody has telescope envy.

• 20:38Neil deGrasse Tyson?

  Yeah, so, whatever size is your, in fact, you go to astronomy conventions, how big is yours?

• 20:42Speaker 01

  Right.

• 20:43Neil deGrasse Tyson?

  You know? It's true, but here's the problem, at some point, you gotta carry the thing to the observing site and above a certain size, you just can't carry it.

• 20:51Speaker 01

  You can't do it.

• 20:52Neil deGrasse Tyson?

  Yeah, you can't even do it, so it's.

• 20:53Speaker 01

  Yeah, I know what you mean.

• 20:54Neil deGrasse Tyson?

  There's more, it's not. Chuck. Chuck out of control.

• 20:59Speaker 01

  Okay, let me shut up.

• 21:00Neil deGrasse Tyson?

  So what we have, so what we have going on in the solar system is that planets are no longer just dots of light with pretty atmospheric conditions that photographed through a telescope, we can actually go there and look at surface features. And so there's a whole frontier of planetary science called comparative planetology. And if there's a mountain on one planet, look for a mountain on the other, there's craters, valleys, uh, riverbeds, you compare one object to another. And, and especially for the terrestrial planets, Mercury, Venus, Earth and Mars, they're small, they're rocky.

• 21:30Speaker 01

  Right.

• 21:31Neil deGrasse Tyson?

  And so we can learn about one by studying another. For example, so we can ask, well, while we've been going to Mars for the past thirty years, guess where the Soviet Union back in the old days, well, guess where they went the most?

• 21:42Speaker 01

  Venus. Really?

• 21:43Neil deGrasse Tyson?

  Yes, and they had a whole series of Venera, Venera spacecraft.

• 21:47Speaker 01

  Venera spacecraft.

• 21:49Neil deGrasse Tyson?

  That's what they're called, that's right, Venera, so that's the genitive.

• 21:52Speaker 01

  Kinda sounds like a medical condition, that's all I'm saying.

• 21:54Neil deGrasse Tyson?

  I'm just saying, well, well, it's funny that you should ask, because in.

• 21:58Speaker 01

  Man, I got a bad case of Venera, man.

• 21:59Neil deGrasse Tyson?

  That's what I'm, let me tell you.

• 22:00Speaker 01

  Go ahead.

• 22:01Neil deGrasse Tyson?

  So, what happened was astronomers, when we figured, you try to come up with words of, for names for where you come, if you're from Earth, Earthling.

• 22:09Speaker 01

  Okay.

• 22:09Neil deGrasse Tyson?

  If you're from Jupiter, you're Jovian, if you're.

• 22:12Speaker 01

  I did not know that.

• 22:13Neil deGrasse Tyson?

  You didn't know that, you didn't, by Jove.

• 22:14Speaker 01

  No, well, you, by Jove comes from.

• 22:17Neil deGrasse Tyson?

  Jupiter, of course, of course, yes, and so, and Venus would be Venusian.

• 22:21Speaker 01

  Venusian.

• 22:22Neil deGrasse Tyson?

  If you're, if you're come from Venus, you're Venusian, and so, the reason why we came up with Venusian is because the proper genitive form of Venus.

• 22:32Speaker 01

  Uh huh.

• 22:32Neil deGrasse Tyson?

  Is Venereal, and the medical doctors got to that word before we did, and I, I am so pissed off.

• 22:39Speaker 01

  That is so cool.

• 22:40Neil deGrasse Tyson?

  I am so angry about that, and now, they took the word right out.

• 22:45Speaker 01

  Right out from one of you guys.

• 22:46Neil deGrasse Tyson?

  And, and so they, and, and why name it after Venus? Because it's the diseases common to love and beauty and all that go with it.

• 22:52Speaker 01

  That makes sense.

• 22:53Neil deGrasse Tyson?

  And that's Venus, the goddess of love and beauty.

• 22:55Speaker 01

  Oh my God, I'm just happy to know that, you know, this little condition I have that it needs antibiotics is so romantic.

• 23:03Neil deGrasse Tyson?

  TMI, right there, TMI, so.

• 23:07Speaker 01

  Oh, it'll clear up, don't worry.

• 23:08Neil deGrasse Tyson?

  Now, here's the problem on Venus, yeah, if we sent you to Venus, it would all be cleared up, because it's nine hundred degrees Fahrenheit there.

• 23:13Speaker 01

  Oh, sweet.

• 23:13Neil deGrasse Tyson?

  There's a runaway greenhouse effect going on there, and that's, makes it very hard to investigate, because your metals melt, it'll melt lead, for example, you can't have lead, lead solder or anything.

• 23:24Speaker 01

  Only Superman could do that, so that's hot.

• 23:26Neil deGrasse Tyson?

  Is that right?

• 23:27Speaker 01

  Yeah, his laser vision.

• 23:28Neil deGrasse Tyson?

  Okay, you know, we should do it.

• 23:29Speaker 01

  Which, which is funny, he couldn't see through lead, but yet he could melt it with his heat vision.

• 23:33Neil deGrasse Tyson?

  Interesting.

• 23:34Speaker 01

  How crazy is that?

• 23:35Neil deGrasse Tyson?

  That's crazy, you know, we're gonna do a special show on the physics of superheroes.

• 23:38Speaker 01

  Get out.

• 23:38Neil deGrasse Tyson?

  Should we invite, should I get you back for that?

• 23:40Speaker 01

  Aw, man, if you don't, I would never speak to you again.

• 23:43Neil deGrasse Tyson?

  All right. That's not, we'll work that one out. And so of these destinations Pluto is on our targets. The ex-planet Pluto. It's got what's called the New Horizons mission. It's booking. It's the fastest Hunka hardware we have ever sent anywhere. It's on its way to Pluto right now. Get there in 2015. And that's, we're headed there. And so. That's one hell of a road trip, man. It's one hell of a road trip. And it's on hugely powerful rockets. Because the principal investigator of that mission wants to make sure you get to Pluto before he dies. See, that's how that works. This is the number one rule. It's like a trip to my mother-in-law's house. Scientific investigation. And so they're all, we have spacecraft going to comets, to asteroids.

• 24:28Neil deGrasse Tyson?

  And so we're all over the solar system now. It's a fun time to be alive. Because the solar system is no longer this distant place. Wow. And when we come back after the break, as I promised before, we're going to talk about life, the search for life in the universe. What are the conditions that a planet or an object have to have? In order for there to have life as we know it. Right. Because maybe this could be some stuff that life as you don't know.

• 24:53Neil deGrasse Tyson?

  You're listening to StarTalk Radio. Stay tuned. More up next.

• 25:10Neil deGrasse Tyson?

  Welcome back. Here's more of StarTalk.

• 25:15Neil deGrasse Tyson?

  Now, we're not going to Pluto to look for life. It's too cold. It's too far. It's too dark. It's too everything that we can imagine that could serve life. But there are other places in the solar system that could serve this need. And we talked to two of my favorite colleagues, Steve Squires and Heidi Hammel. Two, we had a geek fest in my office. Geekin' out. We were geekin' out on the solar system. Just giddy, I can hear the giggling mouth. We were giddy. Let's find out what they say about a search for life in the solar system.

• 25:45Neil deGrasse Tyson?

  We love the planets, but the real goal is we want to find life. Mars has been a seductive prospect for life since the begin- since Lowell.

• 25:52Speaker 03

  Yep.

• 25:53Neil deGrasse Tyson?

  Okay, Percival Lowell.

• 25:54Speaker 03

  Yep.

• 25:54Neil deGrasse Tyson?

  Thought he saw Martian.

• 25:55Speaker 03

  A little misled, but you know, he had the, he had the right idea.

• 25:57Neil deGrasse Tyson?

  His heart was in the right place.

• 25:58Speaker 03

  Yeah, his heart was in the right place.

• 26:00Neil deGrasse Tyson?

  You know, he's the one who invented the canal story.

• 26:03Speaker 03

  Uh huh.

• 26:03Neil deGrasse Tyson?

  Could you quickly tell us that, the canal story?

• 26:05Speaker 03

  Well, basically, what happened was that people looked through a telescope. And they saw, and mo- yeah, a hundred years ago, in moments of brief atmospheric clarity, they could see what looked like a fine network of straight lines on the planet's surface. And they were so straight and so regular that the people looking at these concluded that not only were they evidence of life, they were evidence of intelligent life. Now, they were correct, but the life was at the wrong end of the telescope.

• 26:34Speaker 03

  What they were seeing was an optical illusion.

• 26:36Neil deGrasse Tyson?

  And, and didn't know enough about illusions to.

• 26:38Speaker 03

  Yeah, and, and in fact, there, there's nothing of the sort on the surface of Mars. But as we've learned in recent decades, Mars is very interesting in other ways.

• 26:47Neil deGrasse Tyson?

  Nonetheless, nonetheless, with possible evidence of running water. So the two water places that I know of is Europa, one of Jupiter's moons. One of my favorite places, just to think about, to dream about. Cause I want to go ice fishing on Europa one day. And of course Mars, possibly under, under surface aquifers. And Heidi, how has Europa kept warm? It's not the sun.

• 27:05Speaker 04

  No, it's really kind of a gravitational tidal pumping with the other moons around Jupiter that kind of bend it. You know, the analogy I use is if you take a credit card, you bend it back and forth.

• 27:16Neil deGrasse Tyson?

  I try not to.

• 27:17Speaker 04

  A lot of it gets warm.

• 27:17Neil deGrasse Tyson?

  I try not to do that.

• 27:18Speaker 04

  With old credit cards.

• 27:20Speaker 03

  He's a coat hanger.

• 27:20Speaker 04

  A coat hanger, a paperclip. How's that? You bend the paperclip back and forth a whole bunch and you touch it, you feel it gets warm. Right, same thing is happening with this moon, you know, Europa and Io. They're kind of getting flexed and bent, flexed and bent, and it heats them up. And you know what, don't forget about Enceladus when you're talking about water worlds. Enceladus, we now know is just

• 27:41Neil deGrasse Tyson?

  Moon of

• 27:42Speaker 04

  Moon of Saturn.

• 27:43Speaker 03

  Little tiny one, too. It's also tidally heated.

• 27:46Speaker 04

  Tidally heated, the same flexing to heat it up, but it's just blasting water out of its southern pole.

• 27:52Speaker 03

  Geysers, basically.

• 27:53Neil deGrasse Tyson?

  Are these not ice volcanoes, or what are, no? It's liquid water coming out?

• 27:58Speaker 04

  I- it's water.

• 27:59Speaker 03

  Yeah, you could think of it as volcanoes, it's just that the magma is water instead of being molten rock.

• 28:03Speaker 04

  I mean, you could, if you-

• 28:05Neil deGrasse Tyson?

  It's pressure that builds up and it spews forth.

• 28:07Speaker 04

  It's water. I mean, you could, if you flew a spacecraft through it and collected it and you're able at room temperature, you could drink it.

• 28:13Neil deGrasse Tyson?

  And of course, every place on Earth, we have liquid water, we have life, so therein is the temptation.

• 28:17Speaker 03

  That's where the temptation-

• 28:18Neil deGrasse Tyson?

  What would you bet on Mars or Europa as a, the place, if there's life, other than Earth in the solar system, that we would find it?

• 28:25Speaker 03

  Today.

• 28:25Speaker 04

  Today. Yeah, see, that's the question, is you're talking about life today or life ever existed, because it's a different question.

• 28:32Neil deGrasse Tyson?

  Today.

• 28:33Speaker 03

  I would say Europa. If I knew how to-

• 28:35Neil deGrasse Tyson?

  Europa, not Mars.

• 28:35Speaker 03

  If I, if I knew-

• 28:36Neil deGrasse Tyson?

  Mars, dude.

• 28:37Speaker 03

  If I knew how to do submarines on Europa, I wouldn't be screwing around with rovers on Mars, yes, sir.

• 28:41Neil deGrasse Tyson?

  Ooh!

• 28:41Speaker 04

  What if you dug down into Mars, doesn't it get warmer?

• 28:44Speaker 03

  Yeah, it does.

• 28:45Neil deGrasse Tyson?

  Can't you, it does some-

• 28:46Speaker 04

  You got waters, you get further than that.

• 28:47Speaker 03

  Yeah, I don't know how, I don't know how to drill down hundreds of meters on Mars either.

• 28:50Speaker 04

  Well, you don't know, you know, if you don't know how to drill on Europa-

• 28:53Speaker 03

  But if they're really, if they're- Yeah, I mean, they're both huge technological challenges, but if there truly is-

• 28:59Neil deGrasse Tyson?

  Wait, just, how thick is the ice on Europa, approximately?

• 29:01Speaker 03

  We don't even know for sure that there's an ocean there.

• 29:04Neil deGrasse Tyson?

  Well, I saw the picture.

• 29:05Speaker 04

  Ten kilometers, a hundred kilometers.

• 29:08Speaker 03

  It's likely, but it is untrue.

• 29:09Neil deGrasse Tyson?

  I saw the ice, it looks like-

• 29:10Speaker 04

  I can make a picture for you, Neil.

• 29:12Speaker 03

  It looks like, but you're gonna spend tens of billions of dollars doing a submarine mission to an ocean that you don't know for sure exists?

• 29:19Neil deGrasse Tyson?

  Okay, alright.

• 29:21Speaker 03

  We got work to do there, so.

• 29:22Speaker 04

  Yeah, we gotta learn a lot about the environment.

• 29:25Neil deGrasse Tyson?

  I want this to happen in my lifetime.

• 29:26Speaker 03

  Uh...

• 29:27Neil deGrasse Tyson?

  And I got two key people here.

• 29:28Speaker 03

  Eat healthy, get lots of exercise, okay?

• 29:32Speaker 04

  Go on that low calorie diet. Seventeen hundred calories a day. That'll get you an extra year per year or something.

• 29:39Neil deGrasse Tyson?

  Wear my seatbelt, too.

• 29:40Speaker 04

  But you know what? What might happen in your lifetime is we may find Earth-like planets around other stars in a distance from that star where water could be liquid.

• 29:52Speaker 03

  Yep. I'll tell you another one that could happen in your lifetime, and that is bringing rock samples back from Mars that contain definitive evidence, one way or the other.

• 30:02Neil deGrasse Tyson?

  Fossilized.

• 30:03Speaker 03

  On whether or not there was life at the location from which the rocks came.

• 30:07Neil deGrasse Tyson?

  And ideally, you get to choose your own rocks.

• 30:09Speaker 03

  Yeah, see, I mean, we have rocks from, in fact, I'm sure you've got them in your museum here. We've got rocks from Mars here on Earth in the form of meteorites, but these are rocks that literally fell from the sky. We don't know where on Mars they came from. We didn't pick them. They just came here.

• 30:24Neil deGrasse Tyson?

  They don't have the pedigree that you need to order.

• 30:26Speaker 03

  Mars is a very, very complex place geologically, and to be perfectly honest, most of Mars is pretty boring. Most of Mars is just covered with lava, very dry, very desolate.

• 30:35Neil deGrasse Tyson?

  Solid lava.

• 30:36Speaker 03

  No evidence of water was there. Solid lava. Yeah, solid lava. And, and, and, you know, very ancient volcanic rocks and evidence for life you're not going to find in a place like that. To find it, you got to go to the special places where you have the right minerals, the right sediments, the kind of stuff that can preserve evidence of ancient habitable watery conditions. And those are few and far between.

• 30:56Neil deGrasse Tyson?

  Okay, so we have Mars as a good example of where to look for evidence of past life. Europa is a place to look for possible evidence of current life.

• 31:04Speaker 03

  You could, you could look for evidence of current life on Mars as well, but you probably have to drill deep, and that's hard.

• 31:10Neil deGrasse Tyson?

  Geek Fest continues. Man, that was serious. Now Chuck, you realize that interview in my office took place a few weeks before the announcement that we found Goldilocks planets orbiting, exo-planets orbiting distant stars? Yeah, where they're close enough or far enough from the sun where they can have water and... At the right distance, not too close. Not too close, not too far. Evaporate. Hence the Goldilocks, right? The Goldilocks, exactly. And so for them to say, "This will happen in your lifetime," then happen three weeks later, you know. You ask, you receive. Yeah, like they forked it up. We, we have a tweet that, someone asked from a tweet, this is Trudvertite, that's the Twitter handle. "Is the thought of exploring and terraforming Mars even relevant if we can't even take care

• 31:55Neil deGrasse Tyson?

  of our own planet?"

• 31:57Speaker 01

  Yes, it is. Let me just feel this one.

• 31:59Neil deGrasse Tyson?

  Okay, this one goes to Chuck, apparently.

• 32:00Speaker 01

  We're going to need a place to go.

• 32:03Neil deGrasse Tyson?

  After we mess up the earth.

• 32:04Speaker 01

  Because we're screwing this one up royally, buddy. So we need a place to go.

• 32:09Neil deGrasse Tyson?

  Okay, so you you have the opposite sense of this question. This question is, we don't deserve another planet if we can't take care of our own. You're saying it's because we can't take care of our own that we gotta have the planet.

• 32:19Speaker 01

  Absolutely.

• 32:19Neil deGrasse Tyson?

  My my reply is, if you're tariff, if you have the power to terraform another planet,

• 32:23Speaker 01

  Mm-hmm.

• 32:24Neil deGrasse Tyson?

  you have the power to fix your own planet.

• 32:26Speaker 01

  Wow.

• 32:26Neil deGrasse Tyson?

  Just think about that.

• 32:27Speaker 01

  Wow.

• 32:28Neil deGrasse Tyson?

  If you have that much control over geoengineering.

• 32:30Speaker 01

  Right.

• 32:31Neil deGrasse Tyson?

  What's a what's a what's a few degrees warming? Just crank the knob that lowers the temperature back again.

• 32:35Speaker 01

  Exactly, because you'll know what to do.

• 32:36Neil deGrasse Tyson?

  You know exactly what to do.

• 32:37Speaker 01

  Basically, you'll be able to create a a geothermal thermostat.

• 32:41Neil deGrasse Tyson?

  A thermostat, exactly.

• 32:42Speaker 01

  Basically.

• 32:43Neil deGrasse Tyson?

  Awesome phrase.

• 32:44Speaker 01

  Yeah.

• 32:44Neil deGrasse Tyson?

  Chuck.

• 32:45Speaker 01

  Yeah, I just, I don't even know where that came from.

• 32:47Neil deGrasse Tyson?

  A geothermal thermal thermostat, awesome.

• 32:50Speaker 01

  Dude, hanging out with you is rubbing off on me.

• 32:53Neil deGrasse Tyson?

  Ooh, that just felt good.

• 32:54Speaker 01

  I felt smart for a second. Still don't know what I said.

• 32:57Neil deGrasse Tyson?

  And so we got these.

• 33:04Neil deGrasse Tyson?

  And so so you got these places. Like, you know, Heidi raised an interesting point. And that if you're looking around for other solar systems, star systems, we don't know yet how common our star system is.

• 33:18Speaker 01

  Okay.

• 33:18Neil deGrasse Tyson?

  We've got these eight planets. Get over it.

• 33:22Neil deGrasse Tyson?

  We've got eight. We've got sort of Earth and Mars sort of in the Goldilocks zone. But we have these places outside of the Goldilocks zone kept warm. In the case of Jupiter, it's Jupiter's gravity stressing the moons. By the way, in the old days, people said, let's find a planet with life. But you could have a moon, if the moon is big enough, why not have life on a moon?

• 33:41Speaker 01

  Right.

• 33:41Neil deGrasse Tyson?

  And if the host planet keeps the moon warm, you don't even have to be in the Goldilocks zone of the host star.

• 33:46Speaker 01

  So now, when you guys were talking about this, wait a minute. Tidal heat.

• 33:51Neil deGrasse Tyson?

  Oh, tidal heat, yes.

• 33:53Speaker 01

  Is that when the gravity moves the planet back and forth or stretches it?

• 33:57Neil deGrasse Tyson?

  It stretches.

• 33:58Speaker 01

  And that creates the heat?

• 33:59Neil deGrasse Tyson?

  It's a stretching kind of gravity. And it does that to the to the water, the oceans of the earth that stretches them. And you, Earth turns inside and out of the stretched ocean on the earth.

• 34:09Speaker 01

  Wow.

• 34:09Neil deGrasse Tyson?

  Yeah, oh, yeah.

• 34:13Neil deGrasse Tyson?

  You're listening to StarTalk. Stay tuned for another segment.

• 34:29Neil deGrasse Tyson?

  Welcome back to StarTalk. Here's more of this week's episode.

• 34:36Neil deGrasse Tyson?

  There was a recent data that was released that had a set of a thousand stars, a thousand planets orbiting other stars. And so it tripled the number of total. So we went from 500 to now 1500 stars, 1500 planets.

• 34:50Speaker 01

  1500 planets.

• 34:51Neil deGrasse Tyson?

  In orbit around stars that are not the Sun.

• 34:54Speaker 01

  Okay.

• 34:54Neil deGrasse Tyson?

  And out of those, there's about 40 or 50 Goldilocks planets that were found.

• 34:58Speaker 01

  So there's about 40 or 50 other Earths floating around out there.

• 35:02Neil deGrasse Tyson?

  That could sustain liquid water.

• 35:03Speaker 01

  That could sustain our life or have water.

• 35:05Neil deGrasse Tyson?

  Or Jupiter-sized planets with moons that are outside the Goldilocks zone. So we're casting a pretty wide net in the search for this. Do you realize this whole field, the search for life in the universe? It's called astrobiology. That's a term, if you went 20 years ago, the term never, no one knew how to use it.

• 35:20Speaker 01

  Nobody even knew.

• 35:20Neil deGrasse Tyson?

  It was not really part of the parlance of scientific discourse. It's a field essentially invented by NASA.

• 35:27Speaker 01

  Right, so 15 years ago, that would have been just called BS.

• 35:30Neil deGrasse Tyson?

  Yeah. Well, you need data. Data converts BS to real, to real discourse. Carl Sagan was, of course, a very early proponent of the search for life in the universe. And we can say, we can call him the father of astrobiology in that sense.

• 35:44Speaker 01

  Okay.

• 35:45Neil deGrasse Tyson?

  Although there are other people who had done sort of Earth-based bio-experiments that preceded that. But do you want to stay current on the frontier of astrobiology?

• 35:51Speaker 01

  Right.

• 35:51Neil deGrasse Tyson?

  There's an online NASA magazine called AstroBio.

• 35:54Speaker 01

  AstroBio.

• 35:55Neil deGrasse Tyson?

  Dot net.

• 35:56Speaker 01

  Dot net.

• 35:56Neil deGrasse Tyson?

  The AstroBio.net.

• 35:57Speaker 01

  For all of your astrobiology needs. It's AstroBio.net.

• 36:03Neil deGrasse Tyson?

  So now, one of the, one of the great frontiers here is where you have to ask, how are you going to explore the nearby planets or the distant ones? Do you send a robot? Do you send a human?

• 36:11Speaker 01

  Mm-hmm.

• 36:12Neil deGrasse Tyson?

  Do you send a robot to do what a human can do? Or like, that's, this is the major issue, a major question. And I brought that up with Steve Squires and Heidi Hammel. And let's see what, what their take is on it. One of them is a geologist and one of them is a telescope astronomer. Let's see where they take us on this issue. Given the choice, because it costs more to send people than to send robots. If you had the choice of sending 30 robots to 30 different locations on Mars, or you going yourself, as a scientist, not as adventure explorer Indiana Jones hat-wearing expedition head, I'm talking about... How about we talk about sending you instead?

• 36:47Speaker 04

  Yeah, wouldn't he be able to come back?

• 36:50Neil deGrasse Tyson?

  I forgot about whether we should bring him back.

• 36:52Speaker 03

  No, look, I see where you're going with this.

• 36:53Neil deGrasse Tyson?

  Where's the trade off?

• 36:54Speaker 03

  The answer, my personal answer, is that I would send a human. Okay, and I'll give you two reasons for that. One reason is that what humans can do is so much greater than what robots are capable of now or for the foreseeable future.

• 37:09Neil deGrasse Tyson?

  Wait a minute, every time we send, every time we send a human, they bring out a black box that makes the measurement. Well, why not make the robot pull out the black box?

• 37:15Speaker 03

  No, no, no, there's, there's much more to it than that. Okay, Neil, I have spent the last 20 years of my life trying to design and operate robots that can replicate what a human might be able to do on the Martian surface. What our rovers do in a day, you and I could do in about 30 seconds. That's one thing. The other thing is that humans have a capability to synthesize information, to digest it, to figure out the next thing to do, and to improvise. Robots can't improvise the way humans can.

• 37:42Neil deGrasse Tyson?

  It's not just that we're not there yet. I mean, Moore's law, get us a, you know, this ever increasing rate of...

• 37:48Speaker 04

  I think you've got a couple of billion years of evolution to go to that point.

• 37:53Speaker 03

  We're, we're very, very far away from that. The other reason that I would send humans is...

• 37:56Neil deGrasse Tyson?

  So the brain is still a pretty good device?

• 37:58Speaker 04

  It's a terrific process.

• 37:59Speaker 03

  Very, yeah. The other reason I would send humans is that humans have a capability to inspire that robots simply lack. Someone once famously said, "Nobody's ever gonna give a robot a tectrotape parade." And there is something to that. It's a little squishy, it's a little intangible, but I will tell you that our rovers were built by people like me who grew up in the 60s and 70s watching Mercury, and Gemini, and Apollo on TV, and dreaming of sending spaceships to Mars someday. And now we do that, okay? We were inspired by what we saw as kids, and I think sending humans does that in a way that robots never will. So I think there's a real value to it.

• 38:32Neil deGrasse Tyson?

  Where do you want to go? We could send you somewhere. And bring you back.

• 38:37Speaker 04

  You know, there's a lot of great stuff in the solar system to see. And just picking off the low hanging fruit, you know, I'd, I'd love to...

• 38:43Speaker 03

  Where would you go?

• 38:44Speaker 04

  Where would you go? The next place that I would go...

• 38:46Neil deGrasse Tyson?

  The fruit wouldn't have to be low hanging. Reach for it. Where would you go?

• 38:50Speaker 04

  I'm so intrigued by the outer solar system because we know so little about it.

• 38:55Neil deGrasse Tyson?

  It's good scientific. Juice is flowing here.

• 38:57Speaker 04

  Yeah, we just know absolutely nothing about.

• 38:59Neil deGrasse Tyson?

  You're drawn to where you are most ignorant.

• 39:01Speaker 04

  Yeah, because that's where you learn the most.

• 39:03Neil deGrasse Tyson?

  Most people are only comfortable where they know the most.

• 39:06Speaker 04

  No, no, I, I, I wanna, I wanna, you know, uncover some of these, these things that we just don't know.

• 39:11Neil deGrasse Tyson?

  So give me a place.

• 39:12Speaker 04

  I would like to go to Neptune.

• 39:14Neil deGrasse Tyson?

  Neptune, yeah. Neptune's a beautiful place. Or Neptune.

• 39:17Speaker 04

  Yeah, because, you know, that planet system, not just the planet itself, but it's got an incredible ring system that's chunky and, and it's not smooth and beautiful like Saturn's. It's clumpy. It's very odd, very dynamic. It's changing with time. It's got a terrific moon called Triton, which was captured. It wasn't born with Neptune. It was some object that just got oops, too close, and Neptune's.

• 39:40Neil deGrasse Tyson?

  Stolen.

• 39:41Speaker 04

  Stolen, yeah.

• 39:41Neil deGrasse Tyson?

  Grabbed from interplanetary space.

• 39:43Speaker 04

  This thing is like a twin to Pluto, and it, we know that it has.

• 39:47Neil deGrasse Tyson?

  Triton is a twin.

• 39:47Speaker 04

  Triton is a twin to Pluto. We know it has ice volcanoes. It's got geysers. We've seen them. And so this moon is dynamic and change. So the whole planetary system has something for everyone. I mean, we just learn so much.

• 39:59Neil deGrasse Tyson?

  So you're, you're attracted by the abject ignorance of what we know of the system? Plus, it's just really alien. It's a really alien place.

• 40:07Speaker 04

  It's very different. I mean, these ice giants are, are just so different from Earth. I mean, they don't have surfaces. You couldn't land on it, but you could land on one of its moons, and that would be.

• 40:17Neil deGrasse Tyson?

  See, since I'm fundamentally a, like a galactic person, not a, not a planet person, my destination within the solar system has nothing to do with how much we know. It's just what looks the coolest. So where, so where would you go? I would so go to Titan, and just, and just watch Titan. The, that's the one with the rivers of methane.

• 40:34Speaker 04

  It's got lakes, lakes in the holes.

• 40:36Neil deGrasse Tyson?

  Lakes of liquid methane, and meanwhile, you're orbiting Saturn. Well, I'll tell you, if you wanna go there, you really better eat healthy and get plenty of exercise. It's gonna take a while. All right, thanks, guys, for being on StarTalk. Chuck, you know, if we find life on Europa, you know what we should call it? What? Europeans.

• 40:58Neil deGrasse Tyson?

  Thanks for listening to StarTalk Radio. I hope you enjoyed this episode. Many thanks to our comedian, our guest, our experts, and I've been your host, Neil deGrasse Tyson. Until next time, I bid you to keep looking up.