Planetary Radio: Space Exploration, Astronomy and Science - How to Defend Your Planet

Episode Date: October 2, 2019

Planetary scientist Vishnu Reddy studies space objects ranging from satellite debris to planet-killing asteroids. He shares the status of our effort to avoid the fate of the dinosaurs in a conversation with host Mat Kaplan. Did you know fruit flies were first in space? That’s just one of the random space facts you’ll absorb in this week’s What’s Up segment with Bruce. Learn more about this week’s guests and topics at:  http://www.planetary.org/multimedia/planetary-radio/show/2019/0925-2019-vishnu-reddy-planetary-defense.htmlSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Defending Earth, this week on Planetary Radio. Welcome, I'm Matt Kaplan of the Planetary Society, with more of a human adventure across our solar system and beyond. I was between trips as I assembled this week's show. You'll soon hear from some of the great people I talked with at the NASA Innovative Advanced Concepts Symposium held last week in Huntsville, Alabama. Now I'm off to what I expect will be another fascinating conversation, this time in Kentucky. I'll join a panel of distinguished experts in

many disciplines to discuss how space exploration and space settlement will change society and what it means to be human. I hope to bring you some of that event as well. Advancing planetary defense is one of the Planetary Society's core initiatives. That's why Emily Lakdawalla invited Vishnu Reddy to write about the current state of our ability to avoid the fate of the dinosaurs. You'll find Vishnu's excellent article in the Fall Equinox edition of the Planetary Report. Anyone can read it at planetary.org. I've got the printed edition that goes to our members in my hands.

It provided the pathway for my conversation with Vishnu that you're about to hear. His research at the University of Arizona's Lunar and Planetary Lab focuses on understanding the behavior of space objects, both natural and artificial, in Earth orbit and beyond. Vishnu is part of the OSIRIS-REx and Destiny Plus missions and contributed to the Dawn mission that visited Vesta and Ceres. There has been an important development since I interviewed Vishnu. NASA announced a few days ago the Near-Earth Object Surveillance Mission.

This new infrared space telescope project replaces plans for the NEOCAM spacecraft that Vishnu and I talk about. NASA credited the NEOCAM effort for developing much of the bases for the new telescope. By the way, NEOCAM principal investigator Amy Meinzer has just moved from the Jet Propulsion Lab to the University of Arizona, where I assume she'll work even more closely with Vishnu. Vishnu, thanks very much for joining us on Planetary Radio. And thanks also for this terrific article in the September Equinox edition of the Planetary Report, which has just come out as we speak. It's called The State of Planetary Defense. How well

does Earth understand the impact hazard? Big, big topic for all of us at the Planetary Society. Probably ought to be a big topic for anybody who calls Earth home, wouldn't you say? Yep. It's great to talk to you, Matt. And I definitely agree with you that planetary defense is right up there, along with climate change as one of the biggest threats for planet Earth. Talk about instant climate change. Try a hit by a thousand meter asteroid. You started the article by looking back at a really sobering event that I was surprised to be reminded by your article. It happened almost exactly 25 years ago, July of 1994. You know the one I'm talking about, right? Yeah, that's the comet Shoemaker-Levy 9 impact

onto Jupiter that happened in July of 94, when we had a comet that got ripped apart into several pieces, about 21 to be a little bit more accurate. And over the course of a few days and weeks, each of these fragments impacted Jupiter. So it was one of the most spectacular planetary events that happened in our lifetime. And definitely was a wake-up call for all of us to take a closer look at impacts in general and how they affect life on Earth. Speaking of closer looks, there is an image of one of those impacts on Jupiter. I love that you call it a powder burn. It does kind of look that way. Absolutely. Yeah. So these poke marks that you see on Jupiter are essentially features you see on Jupiter are essentially

features you see on Jupiter's atmosphere. What we see from the Earth is not actually the physical hard surface of Jupiter like we see for the moon, for example. In this case, it's a Hubble Space Telescope image of one of these impacts. And some of these impacts were pretty large, in fact, larger than the Earth. So if they were to happen here, what scientists call them as sterilization event, you would essentially wipe out everything you see on the surface and you start afresh. That gave a lot of encouragement, let's say, to not only the scientists, but also to the United States Congress to act and basically direct NASA to fund a program that would go and catalog these objects.

Yeah, I suppose it wasn't a coincidence that Congress took action that same year. How have we done with the discovery of the biggest and most dangerous asteroids, these rocks that are, you know, a thousand meters or more across? That's right. Yeah. So the initial space guard goal that was set by Congress was to discover 90% of the asteroids larger than a thousand meters or one kilometer. They specifically picked the one kilometer size simply because at that size, it would cause substantial damage to wipe out a small country or a big state in the United States. When you look at threat due to these asteroids,

you want to reduce the risk from the largest objects first, and then you work your way down to the smallest sizes, not only because of the impact threat, but also the numbers. As you go to smaller sizes, the number of objects are more. So we thought it was manageable to find 90% of the asteroids larger than one kilometer within the decade, which was what the mandate was from the United States Congress. And we've done spectacularly well in that size range. So we've managed to find 90% of the objects larger within that congressional deadline. And the Congress came back with a new deadline, which we are still working on right now.

back with the new deadline, which we are still working on right now. There is a terrific infographic in the article that goes through four classes of asteroids by size. And we've talked about the biggest now, these thousand meter plus guys. How about the smaller ones starting at about three meters or maybe 10 feet across? Awful lot of those. How many have we discovered? Very, very few. And the reason why

we've discovered few of them is because we don't see them unless they're really, really close to the Earth. This happens a few times a month. And the reason why it happens a few times a month is when the moon is out of the sky, the asteroid surveys that are based on the Earth basically try and search the sky for these small objects and anytime they come close they would actually try and find these objects the problem with that is that when you find an object you have to track it long enough for it to have a relatively precise orbit so we can actually catalog it we can give it some kind of a designation so in case it comes back we can identify it back to the known object and also

probably try and recover the object when it's due the next time around given that these objects are so small the observing windows in other words how long you can observe from the earth at a given time especially when it's discovered is too short to get a precise orbit and so we oftentimes we find these objects, but we cannot track them long enough to keep them in our catalog. So we tend to lose them. That's a big limitation. Most of these objects, even if they were to impact the Earth,

burn up harmlessly in the atmosphere, or they make it to the ground as small meteorites. So the threat is not very big from these small objects, especially in that meter class size range. I like how you say that for the most part, they worry some people and entertain others. I hope I'm in the entertained by category. Let's go one step up, at least as this infographic describes them. It begins with these rocks or asteroids that are maybe 30 meters across, ranging up to maybe 100 meters or so. Do I have that right?

And do these worry you more so? Yeah, absolutely. And the reason why is that the congressional mandate that we are currently working on right now is to discover 90% of the objects larger than 140 meters within the decades since we fulfilled the space guard goal, which was in 2005. As you can see, we're pretty fast approaching that deadline, which is going to happen next year. And we are not even a third of our way to fulfilling that goal of finding this 90% of these asteroids larger than 140 meters, which are significantly larger than those in the 100 to 30 meter range that we're talking about in that infographic you have there. The challenge even with larger objects is that we simply don't have the assets on the earth that are capable of finding

these things. You know, a lot of them do not have the geometries for finding these objects. And also there are numerous of them, you know, in the 100 to 330 meter range, we have order of magnitude more objects than we have in the one kilometer range. And so finding these objects and tracking them, again, these are equally numerous and relatively hard to track, just like the really small ones we talked about before, like three meter size, but these can actually cause damage, unlike the three meter one that could burn up harmlessly in the atmosphere. The entertainment value goes away when you get to 30 meter size. Let's say that. What kind of damage are we talking about? If, let's say, a 140 meter meteorite, unluckily, maybe one made of metal, one of these nickel-iron fellows,

were to come down on a populated area. So a significant amount of damage. Again, especially if it's a metallic object, if it makes it to the ground, our closest and best analog we have is right here in my home state of Arizona. It's a meteor crater. And that was a 50 meter object, third of the size of the 140 meter we're talking about. And you could see the damage it has caused. It has left a large crater, which is significantly larger than the 50 meters of the impactor size. The crater itself, it's almost a mile across. That gives you the kind of scale. And this happened relatively in an unpopulated area.

It's not something you worry about every day, but the impact threat itself is very stochastic. So we cannot accurately predict saying like, oh, this happens only once in a thousand years, so we shouldn't really be worried about it. It could happen tomorrow, or it could happen next week, or it could happen in 2000 years. So the stochastic nature of it is what we focus on and why we try to find these objects ahead of time. So we want to rule out, say, the threat due to these asteroids in the next 100 years. That's probability for you too, right? And I've been there. I've been a meteor creator. And I have to say, a lot of people have seen pictures of it, but it's kind of like the Grand Canyon. Pictures don't do it justice when you are standing on the rim of that monstrous crater and just imagining the kind of explosive

effects that must have reached for many, many, many miles or kilometers around it when that impact took place. Absolutely. Yeah. And we're very glad that we were not around at that time. Oh, yeah. So let's go on to the third group, the ones that are maybe 140 to about 1,000 meters, since we've already talked about the even bigger ones. The article says there's about a 1% chance of a strike by one of these every 100 years or so. I don't like those odds either. Yeah, that's definitely a scary thought. And I think it's important that we continue to find these objects. Like I said, we are going to come significantly short of the congressional mandate that's going to be due next year. One of the important things

we found out by trying to fulfill the congressional mandate is the challenges in finding these objects from Earth-based telescopes. Interesting thing about asteroids is that just like any other object in the solar system that is reflecting light or radiating energy in different wavelengths, asteroids actually radiate most of their energy in the infrared wavelength. In other words, when you look at an asteroid through a telescope, you're actually in the visible light, in the light that we can see as humans, we're actually trying to look at it in the most inefficient part of its electromagnetic spectrum. In other words,

asteroids are actually very faint in visible light compared to the infrared light. So we think that to fulfill this congressional mandate and find these 140 to one kilometer object, we need to go to space and use an infrared system to find all these objects in a reasonable timescale than the time that we got before, which was 10 years. And this is something that we've talked about before with a number of scientists, including Amy Meinzer, who, of course, is the principal investigator for the NEOWISE space telescope, and hoping to follow on with one called NEOCAM, that I think you're on the team for NEOCAM. That's right. Yeah.

So we've been working at a concept study where we would use a space-based infrared telescope to find these asteroids. Another advantage of being in space compared to the Earth is that it's relatively easy to cool the telescope. Since we're trying to find things in the infrared, everything on the Earth basically glows in the infrared because everything on the earth basically glows in the infrared because everything gives out heat that it absorbs from solar radiation. But if you put a telescope in space, the coldness of space helps us maintain the camera and the telescope itself at a

very low temperature, and it helps us find these asteroids very easily. So to give you an idea, very easily. So to give you an idea, NEOCAM itself is a very, very small telescope. It's only about half a meter across. The lens or the meter on NEOCAM is only half a meter across, but it is capable of finding asteroids that are as small as a few meters or as faint as those that could be found with an eight meter telescope on the earth in the visible wavelength. So you can see the clear advantage of doing this from space. The other thing is there are no clouds in space. You know, we are not affected by weather. So you can observe 24 seven, and you can also look pretty close to the sun. Unlike on the earth, it's really hard to look close to the sun because you're looking closer to the horizon where all the pollution and the atmospheric effects are pronounced.

But in the case of NEOCAM is that it is in a particular orbit that can actually point relatively close to the sun and find those asteroids that could potentially come from a point in the sky that we traditionally don't scan from the earth. I hope you know that we are big advocates of the NEOCAM proposal or project at the Planetary Society. What's your role in that mission at this point? Thank you very much again, you know, for supporting NEOCAM or any space-based infrared concept for that matter. So my particular role is something we talked about before. You know, when you find an asteroid, the most important thing is not finding it,

but continuing to observe the asteroid so that you can get more observations. Once you get more observations, then you can claim the discovery that you have discovered the object because you have a precise enough orbit. So my job on NEOCAM is to do exactly that. So I lead a working group called the follow-up working group. Every discovery NEOCAM makes, we make sure that the detection of that asteroid in NEOCAM field becomes an actual discovery. So we develop a tool that would automatically predict where is this object going to be? Do we need to stop the survey, point the telescope and get more observations? Or can ground-based telescopes get these observations?

Is this asteroid potentially going to impact the Earth? So that becomes a higher priority. So these kind of works. And I also do what is called a follow-up characterization, which is my speciality. So my job description is relatively simple. If something is going to hit the Earth, I tell what it's made of. Anytime EUCAM finds an interesting target, I point telescopes on the Earth and also in space at this object and try and find out what it's made of, because that has implications on what effects we'll have off that impact on the Earth. Sure. I mean, since some of these are pretty porous and just loose agglomerations, is that a word, of material? And the others are those nasty metallic objects, which have a much better chance of reaching the surface

and doing a lot of damage, right? Yeah, absolutely. So yeah, they come in a range of compositions, a range of textures. And so it's very important we understand not just the one that's going to hit us, but also its family members, its class of objects. So we can get some idea about how many asteroids in this particular

size range are made of metal, how many are made of carbon, how many made of rocks. So we want to know the distribution so that in case one comes our way, we have information from other objects similar to that impactor or potential impactor. So we can figure out a mechanism to mitigate this. impactor or potential impactor so we can figure out a mechanism to mitigate this. You also surprised me as you talk about characterizing these objects. So when you talked in the article about how many of them are not just one object, many of them are binary. That's right. Yeah. So about a fifth to a sixth of all asteroids we look at in a particular size range, you know, under 10 kilometers are binaries. That's very important because when you have an impactor coming your way, there's one in five chance or one in six chance that this could

be a double object. And we have evidence for this, not only on the Earth, but also on the Moon, where we see pairs of craters that have been formed at the same time. So we believe that binary asteroids have impacted the moon and also the earth in the past. One of my, let's say, skill sets is to corral the scientists into doing big projects. So I lead an annual or biannual exercise of planetary scientists. These are called planetary defense exercises to check our readiness in detecting and tracking these asteroids, in characterizing these asteroids using a group of scientists from around the world. So we just concluded one of those exercises and we actually tracked a binary asteroid for the very same reasons you're talking

about. I was going to ask you about this because the article mentions one of these exercises that took place in 2017. Are you saying that there has been another one since then? Yep. The 2017 one was focused on a single asteroid. That asteroid was about the size of the asteroid that hit Russia in 2015, the Chelyabinsk. The Chelyabinsk, right. That's right, yeah, on Valentine's Day. We focused on a small object at that time, and that was the TC4 campaign, where basically this asteroid was discovered in 2012, but the orbit was poor enough that we didn't get enough observations because it was small. It was kind of uncertain in the sky where it would be in the time it would come close to the Earth a few years later. So we acted as if this is a new

asteroid we're going to discover. And we tracked this asteroid. And it was an eye-opening exercise because not only were we, you know, we found our strengths, but we also found areas where we needed to improve. The follow-up onto that exercise is the KW4 campaign, where we focused on tracking a larger kilometer-ish size binary asteroid, which we just concluded. And we're currently writing up the lessons learned from this particular exercise. I hope that that's something we'll also be able to learn about when you're ready to release those findings about this exercise. It also made me think of the Planetary Defense Conference exercises that I've covered a couple of times for this program.

And they're very dramatic. They simulate the worldwide response to an impending impact. Are you familiar with those? And is your work related to those? Absolutely. Yeah. So the work we do is also run by the Planetary Defense Coordination Office at NASA headquarters, the exercises we do. planetary defense coordination office at NASA headquarters, the exercises we do. So the only difference between the planetary defense exercises that are done at the PDC conference and ours are real life exercises. We take a real asteroid, we do real observations, and we do real impact predictions. And we also test communication. That's very important. So for the first exercise, we had the entire federal government communication strategy exercised as part of that campaign. Notification went to other federal agencies, including those who do disaster management like FEMA,

and also to the executive branch all the way up to the White House as part of that exercise. The PDC exercise are kind of complementary to it because it happens in a much shorter time frame over the course of a week. And it's more of a tabletop exercise. But there's pros and cons to both of them. Ours are relatively long. They happen over the course of a few months to a year. The PDC ones are shorter, like I mentioned. And they also consider lots of political concerns and international relations. And they really are fascinating. I've talked in the past on this

show and people have heard on the show how truly dramatic they can become when these threats, even a simulated one, even a made up asteroid is confronted by people who may actually have to deal with it when we have a genuine threat. Let's say we discover a genuine threat. How would you say are we ready for dealing with it? It depends on the size of the object and how much time we have. So the size of the object, like we talked about before, dictates the kind of impacts we would have on the Earth. So if it's a harmless small asteroid, it'll be a good entertainment value. You can just go, you know, watch a big meteor come through. But it's anything relatively large, say, for example, the Chelyabinsk size, then you would go into something like

alerting the population to stay away from windows in case there's a shockwave and that would damage these windows and, you know, hurt people. And if it's a larger object, and if we don't have enough time for a mitigation, we would have to go into civil defense mode where we would evacuate just like we would do for hurricanes. There's actually a chart that basically deals with the size of the object versus what options we have to deal with depending on how much time we have. So the best defense against asteroid impacts is time. So we want to find them ahead of time so that we can actually figure out what to do about it in a more proactive way rather than reactive way. Human beings are very reactive, as you know. Yes. And not just human beings. According to a New Yorker cartoon that was printed by that magazine something like

20 years ago, I just found it yesterday by happenstance. And it was two dinosaurs leaning against rocks in a relaxed way. And one is saying to the other, I'm just saying now is the time for us to start to prepare our asteroid defense. Yep. Yeah, absolutely. Absolutely. And I think mission concepts like NEOCAM would simply answer the question, is there anything out there that will threaten the earth in the next 100 years? And one of the outcomes of NEOCAM is that there might not be one. In other words, we don't have to worry about this for the next generation easily. And I think that's a valuable investment of our resources to answer something like that. Sounds like a relatively small investment in consideration of the possible consequences.

Look, before I let you go, I want to turn from the space-based searches to what is happening currently on Earth. You talk about several of these, one of them based at the University of Arizona. But before we get to these big professionally run ones, could you say something about the role of amateurs? Because we talk to them now and then, and it does seem like even though they may not play as much of a role in discovering these objects, we've been told that they do play a pretty good-sized role, are helping to determine the path of these asteroids. Absolutely. Yeah. Amateurs are invaluable in planetary defense. They play a very vital role in doing exactly what you said, which is follow-up

observations. These are very important so that we can extend their orbits and make sure that they are not lost the next time. They also help characterize some of these asteroids to finding out how fast they rotate and what are their rotational property and if they are binaries or not. So I think, you know, it's one of the few branches of astronomy itself, for that matter, or science, where amateurs play an equally important role as professional astronomers. They are also very passionate about this topic, investing in very large telescopes with their own personal resources, and also with the support of organizations like the Planetary Society. You guys give out the NEO grants to help amateurs upgrade their telescope equipment. And that has played a

very vital role in keeping this line of amateur researchers in the planetary defense game as we get to fainter and fainter asteroids. You know, it becomes challenging when bigger professional telescopes are discovering smaller and fainter asteroids because the amateurs have to keep up with those fainter objects by upgrading their equipment. So definitely the support of planetary society has been invaluable in that regard. It's also important that as we get into the next generation of surveys, that we inspire younger amateurs to get into not only astronomy, but also doing planetary defense. And so I think investing in those research to encourage citizen scientists to get into planetary defense is very, very important for not only the community, but also I think as a

society, because these are taxpayers who support the cause of science. I certainly agree. And I also want to thank you for the praise for our NEO grant program, which is really the Shoemaker NEO grant program, the same Shoemaker who was one of the co-discovers of Shoemaker-Levy 9. Go on now to some of these big, organized professional surveys, maybe beginning with the one that's based at your university. Yeah, absolutely. So the University of Arizona runs two asteroid surveys slash follow-up entities. So one is called the Catalina Sky Survey, and the other is called SpaceWatch. SpaceWatch was the first surveys that have started using electronic detectors or CCDs or digital cameras that we have right now everywhere to find asteroids. They have been prolific. They have since transitioned to doing follow-up observations

to improve the orbits. Our biggest survey that we have right now running is the Catalina Sky Survey. An interesting tidbit is that about half of all those asteroids that threaten the Earth, the near-Earth asteroid, more than 50 percent, have been discovered by Telescope Huiron at the University of Arizona. So we have a long tradition in planetary defense, and we continue to improve these telescopes. So the scientists who are working on these have improved their cameras to see a wider field of view. And we've also discovered three of the four asteroids that have gone on to impact the Earth from Catalina Sky Survey. The fourth one was discovered by telescopes in Hawaii. Transitioning to Hawaii, that's the home to two more asteroid surveys.

The University of Hawaii runs the Pan-STARR survey on the mountain of Haleakala on the island of Maui, and also the ATLAS telescopes, which is also located in Hawaii itself. Both of these have different, let's say, target objects. Pan-STARRS tends to go fainter because they have larger telescopes. They don't cover as much sky as ATLAS. ATLAS goes very wide and shallow and tends to find those asteroids that are potentially going to come very close to the Earth in the next week or two. So they're very complementary in nature. So primarily, these two are the biggest entities, I would say, in Arizona and Hawaii that discover asteroids from the Earth. Now, we do have new surveys coming online in the Southern Hemisphere, which is the Large Synoptic Survey Telescope, or LSST.

The optics for those telescopes were also made at the University of Arizona in our MIRROR lab. But it'll be operated by the NSF funding out of Chile, and it will survey the sky to relatively faint magnitude, comparable to that of NEOCAM. Boy, at mirror lab, I've been threatening for years to make a visit there. I've got a standing invitation. Someday I'm going to come and see those big spinning ovens that are also creating the mirrors for the giant Magellan telescope that will be in the southern hemisphere as well. You mentioned very briefly, at least, because you do cover radar in the article in the Planetary Report as well, the role that these big radar dishes play. Yeah, radar is absolutely essential for planetary defense.

I would say after the survey telescopes, radar is probably the number two asset and probably the number one asset for characterization. And I say this despite me being an infrared spectroscopist. And it's simply because operationally, I think radar provides a much more valuable data product that's important for protecting the Earth beyond finding these asteroids. So we have the Arecibo radio telescope that is located in the island of Puerto Rico that is primarily right now managed by the University of Central Florida. And we also have the Goldstone radar that is in your neck of the woods. The difference between these two setups is that Arecibo is much larger, but it's non-steerable, which means it's fixed or it's relatively fixed or it has a short range it can look at in the sky. But the Goldstone

radar is smaller, but it's more nimble. It can point at different parts of the sky. And we've also been working at using the Green Bank radio telescope in West Virginia for planetary defense. And there are other attempts in other countries, for example, in Australia to bring smaller radio telescopes so we can expand this. But radar is absolutely essential for planetary defense. You must have been relieved when it looked like we might lose Arecibo, not just because of hurricane damage, but because there was no money to run it. And it has been rescued, it looks like, by the University of Central Florida and finding new funding. Yeah, absolutely. And I think thanks to NASA's planetary defense program

that has picked up a lot of the funding gap that Arecibo had to make it available to planetary defense and also in general planetary science community. The interesting thing is that during our first planetary defense exercise we did in 2017, Arecibo was central to that exercise, and we had Hurricane Maria go over the island of Puerto Rico. And that actually took out operations there from causing untold damage to the island and the people. So we have to prepare for things like that when we are trying to do planetary defense, acts of God where we have no control over these large weather phenomena. I've got just a couple more questions for you. One is going to take us a little bit far afield from what we've been talking about, natural objects that threaten us up there,

objects that threaten us up there to artificial ones, because I know you study these as well, the things that humans have put up there. Can you describe this work and what you're about here? Yeah, absolutely. So I think the biggest environmental catastrophe that is equally in the scale of what we see in the oceans is in space. The unfortunate part is that we're not in space, like we go to the beach to see the ocean, to look at all the pollution. So for me, protecting the orbital environment around the Earth is an environmental cause. And I have been focused on characterizing, just like I do with asteroids, the so-called space junk or space debris, to find out how we can devise mechanisms to mitigate it how this debris is created in the first place what kind of material degrades over time

and causes the disintegration and creation of these debris so we use the same exact techniques we would use although not with the nasa irtf which i use for asteroids but other telescopes we have at the university to characterize space debris so we can figure out a way to keep it as a sustainable resource for future generations. We only have one geostationary slot. You know, once it gets polluted, it's really challenging to clean it up, you know, just by depending on the sun or the drag to bring the debris down, which we would in the case of low Earth orbit. A few years multiple constellations of thousands of small satellites that will provide tremendous benefits to all of us down here on the surface, but that's an

awful lot of stuff to be putting up in space. Yeah, absolutely. The only saving grace in that case is that low Earth orbit, the drag is sufficiently large enough that some of it will come down eventually, But you only need one debris event to create a lot of problems up there. And we know it very clearly from anti-satellite tests done by, say, China, India. So we know clearly that debris stays longer and sometimes it gets kicked into higher orbit. So that's definitely a concern. And I think it's important that we get the regulations in place and also the mechanisms in place that we safely deorbit these objects. And every object that is being put out there needs to have a capability to maneuver because the worst thing you can do is to have a conjunction between two objects.

When I say conjunction, it's a potential for being an impact where both of those objects cannot maneuver. You know, you can't get out of each other's way. So we should definitely try and think this carefully. And of course, you know, the concern as an astronomer I have is the pollution we have in doing our astronomical imaging and research. These objects would contaminate the data that we collect with ground-based telescopes. So there's definitely different aspects to it. I think it's time we have a serious conversation.

But like I said before, human beings are reactive rather than being proactive. So unless something bad happens, I don't think we will be putting a lot of effort into this. Well, back to that natural threat that we started with, the asteroids. On that topic, are you generally hopeful? Yes, I think so. I think we have a tremendous amount of support from leadership at NASA, especially at the Science Mission Directorate, to push for a concept like NEOCAM, a space-based infrared. We have a lot of support from the public and from Congress, for that matter. Things have never been better for planetary defense. We just need lot of support from the public and from Congress, for that matter. Things have never been better for planetary defense.

We just need the continuing support from entities like Planetary Society to kind of close the deal on putting together a space-based infrared system for tracking these asteroids. And we might find out that there's absolutely no threat to the Earth from near-earth asteroids over the next 100 years if we have something like NEOCAP. That is clearly an option. Well, let's hope that that's exactly what we learn, or if we learn otherwise, certainly that'll make these kinds of observations even more important. Vishnu, thank you very much for this very clear exploration of those threatening skies above us, and again for this article that is in the

September Equinox edition of the Planetary Report, the Planetary Society's quarterly magazine. All of our members, of course, got the print issue. I have mine right in front of me. But it is also available at planetary.org for free for absolutely everybody. And I recommend that they take a look at your article and get the benefit of those great illustrations that accompany it. Thanks for having me. And by the way, Vishnu Reddy, you can follow him on Twitter. He's MooneyGuy. Vishnu Reddy is an associate professor in the University of Arizona's Lunar and Planetary Laboratory. This week's What's Up visit with Bruce Betts is moments away.

Time for What's Up on Planetary Radio. We are joined by the chief scientist of the Planetary Society, the program manager for LightSail. It's Bruce Betts. Welcome back. Thank you, Matt. We're going to have fun with the contest this week. Well, we always do, but there's some really fun stuff with these dwarf galaxies. But I don't know, can you see any of these from the Northern Hemisphere? No. Well, I mean, yes, you can see a lot of them. If you use binoculars or a telescope, you can see some of them,

but you're not going to have the possibility of doing the naked eye, seeing like you can with the large and small Magellanic clouds from the Southern Hemisphere. So congrats, Southern Hemisphere. Well, what else can we see up there? Well, if you're picking this up pretty soon after it comes out, you can see Jupiter near the moon looking lovely on October 3rd in the evening in the West. And the only thing that really changes is the moon won't be there on other nights. So you can still check out bright Jupiter. Getting lower and lower, catch it before it goes away. And then Saturn to its upper left, and the Moon will move along.

And so on October 5th, the Moon will be hanging out near Saturn. Check out the evening planetary stuff. I was just looking a few months ahead. There's just wacky planet stuff going on, and those who get up before dawn, which is incomprehensible to me, but they will have some good experiences in the coming months, just not much right now. In terms of planets, there's plenty of stars. I'm sure you'll keep us informed. All right, we move on to this week in space history. It was 1957 that Sputnik 1 became the first artificial satellite of the Earth.

And two years later, Luna 3 provided the first pictures of the lunar far side. The glory days of the Soviet Union in space. Indeed. We move on to random space. I don't know. I'm entertained. Thank you. random space fact. I don't know. I'm entertained. Thank you.

I hope other people are. They don't just think, gosh, not that again. All right. So animals in space. The first animals sent into space were fruit flies aboard a U.S. launched V2 rocket in 1947, launched from the White Sands Missile Range in New Mexico. New Mexico?

I'm going with New Mexico. The rocket reached 109 kilometers up, so by anyone's definition in space. The fruit flies, I know you're concerned, they were recovered alive. I wonder if they stayed that way for a long time. Well, I'm guessing they're not alive now. I mean, how long can a fruit fly live? It's a space fruit fly retirement home in Boca Raton, I think. I was going to share a side story that I thought was funny, but that's funny itself. But I was going to share a side story that I thought was funny, but you know, that that's funny itself, but, but I'm going to do the side story.

It's not a random space fact, which is why I'm doing it as a side story. It's a random aeronautics fact. First animals use an aeronautic exploration, 1783 when the Montgolfier brothers sent a sheep, a duck and a rooster aloft. It sounds like the beginning of a joke or a logic puzzle. Doesn't it? In a hot air balloon to see if ground-dwelling animals can survive.

And kudos, Wikipedia, for the following comment. The duck served as an experimental control. That's great. Real science. Yeah, I remember that. And then they sent up, I think, prisoners. They sent up convicts that were the first humans. That I did not know. Contest time.

Back to seriousness. In the contest, not so seriously, I asked you to name your three favorite satellite galaxies of the Milky Way. So the only real requirement was that you name three satellite galaxies of the Milky Way. How did we do, Matt? Well, the turnout wasn't as great as most weeks, but the people who did enter were passionate about their choices. And, of course, there were no wrong answers as long as they were all satellite galaxies. Here's our winner, Chip Kaplove of beautiful Novato, California. His favorites are Sagittarius dwarf elliptical galaxy and the small and large Magellanic clouds. And he threw in Canis Major dwarf galaxy. And he says, thanks so much for the podcast. I look forward to it every week. Chip, congrats. You're going to get a Planetary Radio t-shirt.

You'll have to tell us what size you want. And a 200-point itelescope.net astronomy account. Did you hear anything else? Yeah, we sure did. Last week's winner, Jordan Ticknan in Pasadena, right here at home. Buddhists, how do you pronounce it? Buddhas, Buddhies, Buddhists won. Well, I'm terrible at these space pronunciations, as people know.

I was taught Bayotis, but I'm pretty sure that's wrong. Buddhas, Bayotis, Ba-oo-di. I prefer Ba-oo-dis. To adopt your pronunciation, if I can approximate it, Ba-oo-dis 1, Horologium 1, and Fornax Dwarf Spheroidal. We got those from Jordan because he says they're the funniest. Laura Weller in the UK. My favorite satellite galaxies are Draco, Pegasus, and Hercules.

As I have a pet, mostly cats named after each of these. The current cat is named Drogo, which would have to be my favorite name for a new satellite galaxy. So we'll file that with the IAU, okay, Laura? Darren Ritchie, also a recent winner, Renton up in the state of Washington, the large and small Magellanic clouds and the Sagittarius dwarf. But this is really why I'm reading it. He said, if we end up in one big, happy galaxy after the big smash-up in three to four billion years, he thinks it should be called

the Milk Andromagelitarious Galaxy. And then Triangulum will be one of our satellites. Finally, our poet laureate, Dave Fairchild. I really think he did a wonderful job. Coma Berenices is a galaxy so small, just 3,700 times as bright as our star Sol. And then I'll take Triangulum with just a thousand suns. You barely start to count them, and suddenly you're done. And last is Sagittarius, a dwarf spheroidal bunch. And shortly it is going to be the Milky Way's next lunch. Impressive. Impressive.

He throws in, my fourth would have to be the one that Elon Musk missed the boat on. Instead of launching a Tesla Roadster, he should have launched a 1959 Ford Galaxy. Very clever. Thank you, Dave. All right. This is simple if you're paying attention to lunar exploration and not as much if you're not. As of September 2019,

what spacecraft are active on the moon's surface? Go to planetary.org slash radio contest. Wow. You have until the 9th. That would be Wednesday, October 9th at 8 a.m. Pacific time to get us the answer for this one. You might win yourself.

We'll give away another T-shirt, another Planetary Radio T-shirt. It's gorgeous. And a 200-point itelescope.net account for 200 bucks worth of time on that international network of telescopes operated by a non-profit down under. I should say the key word is active, so things just lying around on the surface, not actually communicating, don't count. All right, everybody, go out there, look up in the night sky, and think about beach balls. Thank you, and good night. Beach balls in space. That would be the echo satellites, I think. Look it up. He's Bruce Betts, the chief scientist of the Planetary

Society, who joins us every week here for What's Up. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its watchful members. You can join our fight to protect Earth from angry space rocks. Learn how at planetary.org slash membership. Marco Verda is our associate producer. Josh Doyle composed our theme, which was arranged and performed by Peter Schlosser. I'm Matt Kaplan at Astra.