Asteroids Headed Towards Earth with Rick Binzel

0:00It's not every day you get to talk to someone who invented a hazard scale, and studied the asteroid, has an asteroid named after him, and that's my man. Yep, and that is this show, and you will find out we are all going to die. Eventually. Coming up on StarTalk. Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.

0:38This is StarTalk. Neil deGrasse Tyson, your personal astrophysicist. Got with me Chuck Knight. Chuck, baby. Hey, what's happening, man? All right, co-host, comedian. Yes. You know what we're going to talk about today? What? Oh, my gosh. Go ahead. Hazardous asteroids, Pluto, and Planet Nine. So are we saying that Pluto and Planet Nine are just now demoted to hazardous asteroids? Because you know, they were on planet. You knocked them down. You know, humiliated them completely. You're not over that. You still haven't gotten over that. And then it was like, okay, you're a dwarf planet. It was like, oh, at least I get to be a planet.

1:16Now you're just like, you know what? How's this asteroid? Well, while I have some expertise in this space, I don't have all the expertise I want for this show. Okay. So we went back. Uh-oh. One of my peeps. Okay. One of my people. All right. I got one of my people who invented the international scale to measure how hazardous an asteroid will be to life on Earth. Okay. That is a hell of a quality to have on your resume. I'm just saying, the business card. I tell you whether your ass is fried or not. That's amazing. So let me introduce us all to Rick Binzel. Hey. Professor Richard Binzel. Rick, how you doing, man?

2:04Hey, Neil. Great to see you. Chuck, nice to see you. Nice to see you. Yeah, so you are retired now, Professor of Planetary Sciences at MIT. Which stands for?

2:17Massachusetts Institute of Technology. Thank you. That took you too long to... Well, you know, I was going to say something smart-ass, but you saw me bridling myself. Yes, you did bridle. You did bridle. and you are the inventor of this hazardous scale, hazard scale, the Torino scale. We'll get into that in a moment. Okay, I got my first question already. All right, you're a co-investigator on OSIRIS-REx. Remind me, Rick, that was the mission that did the, was that the one that did the touch and go? Yes, OSIRIS-REx was the touch and go that successfully returned an asteroid sample to the Earth.

2:51Back to Earth, so that's badass. That's more than badass. We're going to find out if it had any bugs in it. Yeah. And, of course, my boy has an asteroid named after him, 2873 Binzel, and that is not his password on his account. No, sorry. He tells me that's not his password. He's also a staunch Pluto lover. Oh, really? So we've had some dust-ups in our day. I can only imagine. Put your thumb down, dude. So we're old friends. So we went to graduate school together. Oh, wow. We were in the same class in graduate school. That's pretty cool. That's pretty cool. Yeah. And - That was a previous millennium, too.

3:35Ooh, yeah, way back. Okay. Since you were in school at the same time, what was the most advanced technological equipment that you had at your disposal when you were in school? Because that will give people a really - I got one for you. Ready? Go ahead. At the time, you were able to visit someone's house, dial a set of numbers to forward your phone number to their phone number so that if someone was calling you at home, they could still reach you while you were at your dinner party. Oh, wow. So that you could get your phone number to follow you. How telling. That's amazing. Yeah. It's like, it's.

4:11I thought that was good. You could have your phone number follow you. Correct. You're forwarding your own calls to you. Correct. Rick, do you have an opinion on this? You could connect to the, from your home, you could connect to the computer on campus by dialing, literally dialing a phone, sticking it into a box that had two earmuffs to connect your phone. So the handset of the phone, yeah. A handset of the phone into a, what was called an acoustic coupler. And you could talk to the computer on campus from your own home. That was amazing. That was amazing, huh? Amazing. At 300 baud, 300 bits per second.

4:51Yeah. Oh, my God. That's awful. We were not streaming videos back then. That's amazing. You published a paper at age 15? I forgot about that. What was that paper on? It was on asteroids, Neil. Oh, okay. He goes back. Yeah, we had an experience of a camp run by a Columbia professor named Joe Patterson. And he just reached out to high school kids, gave them this fantastic experience that was formative in our careers. And so many of those students became professors and professional astrophysicists. Anyway, so it was a super opportunity. And I haven't stopped since. There was a research project in that camp.

5:37That's right. That's right. Okay, so I attended the same camp, but not at the same time. Not at the same time. But we didn't know each other at the time. We get into graduate school, and we find out that the two of us, plus another person in our class. In that camp? All attended that camp. It was an astronomy camp called Camp Uranaborg. Camp Uranaborg. Do you know what Uranaborg is, historically? I believe it's the Borg ship. The Borg? Star Trek Borg. When you're on the Borg ship, you're on a Borg. You're on a Borg. You're on a Borg when you're on the Borg ship. Okay, that's a good one. That's good.

6:11No, but that's good. It was the observatory of Tuchelbrot. Oh. Tuchelbrot. Tuchelbrot. That's your buddy. That's my man. You like that dude. He got all the data on the planets. And so it was a camp night. And we lived nocturnally. We slept during the day and up during the night. It was totally geeked out. We're both 14 or 15. Right. Yeah, exactly. So Rick, one other thing about your time in graduate school, which betrays some of your affection for Pluto, is Rick made, correct me if I got this wrong, he made the first measurement of the light dimming of Pluto's moon going in front of and behind Pluto.

6:54So, Charon transiting Pluto. Correct. And that was the best evidence available at the time that the moon even existed. amazing and then isn't it what isn't that what allowed people to calculate a true mass for pluto and and its size and all this that's right neil uh when you have a body in space unless you have something orbiting around it um you know you use kepler's third law to to calculate the mass of the primary of the mass of the system what's kepler's third law please dude why do we have to explain that to you just because you know oh for other people you want other people to know about not not me i'm just saying some people might be wondering what kepler's third law is all right so kepler's third law is a relationship between the orbital period of um of an object uh compared to the mass or the mass of the primary the mass of the system and so if you can measure the size of the orbit and the orbital period you can calculate the mass of the system and confess rick that we got the mass for pluto and was way littler than people wanted it to be confess that right now on my show.

8:03The mass of Pluto is what the mass of Pluto is. Oh! Let me tell you something, Rick. You do great in Congress. Well, of course. That put you on Pluto's radar from Jump Street right there. So I was not surprised that he turned out to be a staunch Pluto lover his whole life. Because he birthed Pluto's mass. Yeah, but by birthing Pluto's mass, you also birthed its demise. but go ahead so neil i was looked at pluto for five years i actually spent about 10 or 15 years total working on the pluto system but we started looking to see if we could detect this moon around pluto um about 1980 and um and you know it was a five-year search of uh looking for these transits and that didn't show up until 1985 and then they were continuing from about 1985 to 1990.

8:57It's the same technique that we use for looking at planets around other stars, of course, transiting exoplanets. But this was planetary transits, and we were kind of doing it before it was popular. Now, Rick, you just reminded me of something. There was a fuzzy photo of Pluto, and there was a little bump on the edge of what is the circular outline. Fuzzy. A little bump. And that was a hint if we believe the photo and the emulsion, because back when there was authentic photographs. Right. Right? If we believe that, that meant maybe it has a moon. And I was just reminded that not all transits go exactly in front of the thing you want them to transit.

9:41Right. So if the angle is wrong, it's going to— You're not going to see it when you think you're going to see it. So that's why you were looking for it, and you didn't see it for four years, because our sight line to it wasn't properly oriented yet. Did you know that at the time? Yeah, Neil, that's right. I mean, what we didn't know is we didn't know what that angle is or the inclination of the orbit. And so we didn't know when the Earth, most of the motion around, in this case, was the Earth's motion around the sun. We just simply didn't know what the inclination of Charon's orbit, that's what we call the moon today.

10:18We didn't know the inclination of Charon's orbit. So we didn't know when it would become edge on to the earth. And, you know, but going back to those bumps, that was 1978. Those were on glass plates. That's when telescopes, we didn't have CCDs. We didn't have those electronic detectors yet. Back in the day. Back in the day. You had to climb uphill in the snow both ways to get to the telescope. Now that's when telescopes, here's what you did. you put your head under a hood. The old man hour here. Okay. So anyway, those bumps and those fuzzy images would move around and it moved around with about a 6.4 day period, which we knew was the rotation period of Pluto.

11:03So it all made sense. But, you know, we really didn't know and make sure that it wasn't some funny photographic effect until we got those transits in 1985. And those first transits were just along the top edge of Pluto, along the pole of Pluto. And so it was the beginning of a long series of these transits that we actually used to make the first maps of Pluto. Well, because you can say how it dims or brightens as Sharon moves across it. So you get a blunt understanding of the reflectivity. Exactly. Exactly. So if it goes across a dark spot, the light doesn't change very much. But suddenly as the edge of the moon goes across Pluto and you get a big light drop, then you know there's a really high albedo spot underneath.

11:45Very cool. High albedo. Albedo. I love that word. Yes. It's almost, do you albedo? I albedo. No, you just made it creepy. You just made it very creepy. It's a fun word that gives no indication of what it means. That's true. Right? Yeah, you would never know what it was. Tell us about albedo, Rick. Because albedo is half your work, right? Yeah, albedo is a fancy name for reflectivity. You know, something with a low albedo doesn't reflect very much light. and something with a high albedo reflects a lot of light. So ice is a very high albedo. A lump of coal has near zero albedo. A few percent, yeah, a few percent.

12:24And a mirror or just a coat of white paint would have very near 100 % albedo. All right, this is starting to sound very racist.

12:47Hello, I'm Finkie Marock-Allen, and I support StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson.

13:05Let me ask you this. A long time ago, I read this article, and I mean, it was long ago, and it talked about, because you just said reflectivity and albedo, it talked about how Pluto was so reflective the way it was that they were able to determine that that's because it was mostly ice, which means it was a lot smaller than they actually thought because what you were seeing was more reflection than you were actual body. If you don't know anything about a cosmic object orbiting the sun, you'll make an assumption of what its albedo might be based on other albedos that you have measured, correct? That's right.

13:45That's right. So when you first discover something, you make a best guess that it's albedo or reflectivity. And then maybe someday you get the actual measurements and you can refine it. All right, so what was your first presumption of the albedo of Pluto? Probably around 20. 20%, okay. Okay. And so given its brightness, you would say, If it's that bright and it's only reflecting 20 % of the light, it must be this size. Okay. And so now, given that it has an icy, more reflective surface than previously, its albedo jumped from 20 % to what? Into the 30s, maybe up to 40%. Okay. Oh, wow. Yeah, factor of two almost.

14:26That's a big deal. That's a big deal. That work. All right. All right. By the way, you're in my Pluto book. I mentioned you. I don't know if you remember that. I believe the actual words were, take that, Rick. No. No, that is not.

14:43Let's go back to asteroids. A big part of your career has studied asteroids. Cool. And you were at a conference in Torino, Italy, where you proposed a way to track how hazardous an asteroid might be. And it came to be known as the Torino scale. Which I have a problem with because I understand that there's a 2873 Benzo, okay? And that's an asteroid named after you. Well, why wouldn't it just be the Benzo scale since you're the guy that came up with it? Why so humble, man? You got to take it while you can get it, okay? Grab the gusto and the glory. Like, you know, we live in the time of Trump now, man.

15:27You know what I mean? It's the best scale, the biggest, the most beautiful scale. It's wonderful. It can measure everything. It can measure everything, not just asteroids. It's used by plumbers. It's used by carpenters. It's the best. But why not? Why call it the Torino scale and not the Benzel scale? Well, it is wonderful, and it's the best. Oh, there you go. I love it. Whoa. Yeah, I'll just say the Torino scale or how we talk about asteroids is something that we have to do very internationally. And so the fact that it was adopted at the conference in Torino gave it more of that international flavor.

16:09This is my people. All scientists, you're all the same. Scientists are always sharing the glory and sharing the wealth with one another and collaborating with one another. Don't say that like it's a bad thing. Do you know what world you live in is what I'm saying. No, that's fantastic. I'm so happy for that. That's great. Now, last I read up on this, but it's been a while, so forgive me if I misremember. This scale has multiple factors operating simultaneously, right? One of them is the risk that it will hit Earth. And two is how much damage will it create if it does? Ooh. Those are combined into this one scale.

16:54Is that correct? Consequences versus probability is the basis for the scale. Rick, if memory serves, the Torino scale, there's more going on than just a number. So remind me what you put into it. First of all, the Torino scale is a 10-point scale from 0 to 10. All right, 0 is really good, and 10 is a really bad day for the dinosaurs. And the way you calculate where an object falls on the Torino scale depends on the size or the consequences of what that object would be if it struck the Earth versus the probability, the current best estimate for the probability that it could impact the Earth. And so it's two dimensions, consequence and impact probability.

17:42And is the scale pointed at specific asteroids that are out there, or is it just a generalization for any body that might come our way? Well, it could apply to anything, but it really only matters for objects, asteroids that have orbits that can come close to the Earth. If you're in the main belt between Mars and Jupiter, you know, you're not going to bother the Earth. You're a zero. You're a zero on the scale. Yeah, they're zero. They're zero. How about the asteroid with your name on it? What's the hazard scale for that? Oh, man. Zero. Zero, I'm afraid, or I'm happy to say. Yeah, I was going to say, because that would— You don't want the asteroid Benzel come and take it out.

18:25Benzel at an eight, and it's like, okay, this whole thing was rigged. He created the scale, and now the asteroid— He's the one that's going to take us out. That takes us out. That's a Lex Luthor move. Right, exactly. Yeah, yeah. You know, at the lowest level, you know, things are green. You have a green level, which means, oh, this is normal. We're going to find a lot of these. We're currently at that next level up, which is yellow, which just says these merit attention by astronomers. So that's what level three is, is merits attention by astronomers. And if the probability gets worse, we would go to orange, which means there's a possible threat here.

19:03And where we want to stay out of is the red zone of 8, 9, and 10, which means we have 100 % probability of hitting the Earth. And now it's a matter of what would be the consequences. And those consequences depend on where the object lands. So we're in the yellow zone. We'd rather be green. And if we go completely to zero, that's just colorless. That's just the blank zero. And so we expect this object, the odds are greatly in our favor, we'll get it down to zero. we just have to keep watching it and refining that track and get the information we need to drive it down to zero. So it's green, yellow, orange, red.

19:43Four colors? Correct. Got it. Very simple. And zero is no hazard, so it doesn't even get a color. So recently, 2024 YR4, the two letters and then the numeral, has been in the news. By the way, it's one of, I think, tens of thousands of Earth-crossing asteroids. So this happened to be the one to talk about today. Okay. We saw that it had a 1.3 % chance of hitting us. What does that mean if that number is given? When you discover an asteroid, you know, you're only seeing a tiny piece of the orbit as it's moving through space. space and so you know we'd like to project forward uh extrapolate that position um you know for decades if not centuries into the future just to make sure that it's not going to intersect with the earth and we do that for every asteroid that's discovered he didn't say slam into earth and kill us all intersect intersect right it's a very dispassionate word oh without a doubt yeah go on so we do it for every asteroid we you know every time we discover an asteroid we'd like to make sure that we know that one's on the good list and not on the naughty list.

20:58And, you know, in this case, we know this asteroid in the year 2032. And in fact, every four years, it comes somewhere near the Earth. But we find in 2032, it's going to come close to the Earth, probably about as close as the moon or closer. And we simply don't have enough precision in terms of how well we know where that asteroid is precisely going to be in 2032 or other decades in the future to know for sure that it's going to miss the earth and so because we know because we can't say we're certain it's going to miss it gets a probability of uh of intersecting the earth so that's just simply where we are it's it's really that that probability number is really a measure of you know what we don't know it's not not a measure what we know it's what we don't know because we simply haven't been able to track this thing for very long.

21:52Here's something that might be new to Chuck. Were you able to get a pre-discovery image of this asteroid? When we discover an asteroid that has some future chance of intersecting with the Earth, one of the tricks we can do is go back and see if it's shown up in images that we've taken of asteroid searches many years before. because if we can find it like we that it was someone accidentally saw it four years ago but didn't measure it um that gives us another four years of an orbital length that we can use to calculate forward and so these are called pre-discovery images and i know people have been searching the records for pre-discovery images to get a longer track on this asteroid But those haven't shown up.

22:40You know, the asteroid 2024 YR4 is simply a pretty small object. It's probably about 50 meters across something like what Tunguska Siberia experienced in 1908. And, you know, for the longest time, we never had the capability of even seeing these objects out in space at great distances. And it's simply our capabilities have just gotten so good that we're starting to see really small objects far away. And so we can start to make these extrapolations forward. And, you know, this is just the first of probably many cases to come where our capabilities exceed the precision of computation. So we'll have lots of these cases, I think, coming along.

23:36So I posted a short video in a series that we do called What's Up With That? And that's where my producers say, Neil, this is in the news. We should, what can you tell us about that? I spent five or ten minutes. I commented that when you have an uncertainty of an asteroid risk of hitting Earth, as time moves on, that uncertainty goes to one of two numbers. It goes to 100 % or to zero. once you have a tighter and tighter knowledge of its orbital path. And so recently, it jumped from 1.3 % to 2.3%. It's on its way towards 100. Rick, what's going on? Protect us. And when do we need Ben Affleck? No, it's Bruce Willis.

24:29Yeah, know your disaster movie. Yes, dude. Well, Ben Affleck was in that movie. Yes, he was, but he wasn't the hero. Yeah, but I like Ben Affleck. Okay, fine. He was Batman. Don't confuse him with that. Well, Batman, I wouldn't call to save me from an asteroid. That is for sure. That's a Superman job, if ever. If ever, right, right. So is this on its way to 100 %? Yeah, so Neil, as you just said, ultimately when we get the final answer, we'll know it's either 0 % or 100%. It either hits you or it misses you. and the odds are greatly in our favor we're about 50 to 1 right now that it's going to miss so i like those odds it turns out for this asteroid the region of uncertainty is like this long spaghetti string that stretches from beyond the moon all basically all the way across the moon's orbit and it happens to part of the string happens to lie on top of the earth and so that spaghetti string, and we use Italian pasta because it's the Torino scale, that spaghetti string will shrink as we get more and more data that improved the track of the asteroid orbit.

25:44But until that spaghetti string shrinks and doesn't have the Earth underneath a piece of it, we can see that probability number bounce around. There's really no surprise there. And I'll just say that ultimately we'll get to the final answer and that uncertainty will shrink to the size of a grain, basically a tiny grain. And so the chances are that when we shrink that uncertainty region or that spaghetti string down to a single grain, that single grain could be further than the moon. It could be somewhere between the earth and the moon, but the chances of that grain being on the earth are just that few percent.

26:24Okay. But if it is on earth, the grain could be on top of Hackensack, New Jersey or Hoboken where you live? Hoboken. Hoboken. And I thank you for destroying where I live. Often when we think of an uncertainty I think of a circle and it's most likely to hit in the middle of the circle and less likely toward the edge. But what you're saying is given its orbit and the orientations the circle is now elongated maybe to an ellipse but this is a severe ellipse is so elliptical that it's a spaghetti strand. That's what you're telling me. That's right. What we call the uncertainty ellipse is really just sort of flattened out into this very long string.

27:03It's like you take pasta and you keep stretching it and stretching it. And this uncertainty region has just stretched out into this long spaghetti string. Yeah, but is it linguine or fettuccine? No. I thought it was linguine to start, but it's now getting so thinly stretched out. It's definitely spaghetti. And I don't think it's quite angel hair pasta yet, but definitely spaghetti. Torino strikes a game. Yes. And what sauce is with this? I need to know. I need to know what sauce we're putting with this meal. That's a personal choice. Okay. Okay. All right. So this is 50 meters across Tunguska scale.

27:40And by the way, we didn't have telescopes monitoring for killer asteroids in 1908. So this just hit the atmosphere and exploded on impact with our air, given how fast it's going. So without these telescopes, if this hit us, it would be just another surprise air blast. All right? But we are wise astronomers today. So my question is, if it does hit Earth, is there an easy rule of thumb for how big a crater a 50-meter asteroid would make? Yeah, it's 10 to 20 to 1. So an object that's, say, 1 kilometer across would make a crater about 10 or 20 times that size. Fortunately for a 2024 Y04, it's about 50 meters across.