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Donovan Mathias and Eric Stern Talk About Asteroid Threats

Season 1Jun 22, 2018

A conversation with Donovan Mathias and Eric Stern. Eric is a research scientist here at Ames who supports the agency’s Planetary Defense initiative, and Donovan is an aerospace engineer in the NASA Advanced Supercomputing Division.

Eric Stern and Donovan Mathias

Eric Stern and Donovan Mathias

A conversation with Donovan Mathias and Eric Stern. Eric is a research scientist here at Ames who supports the agency’s Planetary Defense initiative, and Donovan is an aerospace engineer in the NASA Advanced Supercomputing Division.

Transcript

Kimberly Minafra:You’re listening to NASA in Silicon Valley episode 96. I’m Kimberly Minafra. This week our guests are Eric Stern and Donovan Mathias. Eric is a research scientist here at Ames who supports the agency’s Planetary Defense initiative, and Donovan is an aerospace engineer in the NASA Advanced Supercomputing Division.

Eric and Donovan are talking about the research they conduct on meteor entry and breakup, to better understand how these near-Earth objects burn off when they enter the Earth’s atmosphere, and the potential risks they pose.

We’ll begin our conversation with Donovan Mathias.

Music

Host (Kimberly Minafra):Tell me a little bit about yourself. How did you actually end up at NASA?

Donovan Mathias: Well, when I was going through high school and trying to decide what I wanted to do when I grew up, I was really interested in aerodynamics – you know, cars, motorcycles, airplanes. I grew up in a racing household, so my dad always really liked to talk about the race cars. And so I think that’s what actually brought me into the field. When I was going through college and even graduate school, I was a low-speed aerodynamicist. Nothing to do with what we’re going to talk about today. I liked airplanes. I liked cars. I liked racing vehicles.

Host:Now, “racing,” you mean NASCAR or Indy 500 or Grand Prix, or . . . ?

Donovan Mathias: Oh, all of them.

Host:Oh, wow. This is the –

Donovan Mathias: We were a big Formula 1 household, but . . .

Host:Now you’re hitting a chord in my heart. I love it. Okay.

Donovan Mathias: Okay. Yeah, that was definitely a big part of growing up.

Host:Now, did you actually get to race, too, as a kid?

Donovan Mathias: Well, we raced go-carts.

Host:Oh, cool. Yeah, that’s how this starts.

Donovan Mathias: Yeah, that’s right.

Host:That’s awesome.

Donovan Mathias: And then took a different path.

Host:Hey, rockets to race cars. There’s actually a thing about NASA on that, so we may look that up later.

Donovan Mathias: Okay.

Host:Well, thank you, Donovan.

Donovan Mathias: Yeah.

Host:How about you, Eric? How did you get . . . What landed you here?

Eric Stern: Well, I’ve always been interested in space. I was inspired by NASA, the shuttle, and whatnot when I was a young kid. And I thought for a long time that I wanted to be an astrophysicist.

Host: Wow.

Eric Stern: But when it came time to go to school, I didn’t think I was really graduate-school material. And I knew that I would need that. So I decided to do aerospace engineering so that it would provide me a pathway to get into NASA without having to go to graduate school. I ended up going to graduate school, anyway, and got my PhD. But ended up where I wanted to be and, along the way, discovered a love for computational fluid dynamics –

Host:Oh, wow.

Eric Stern: – and hypersonics, and re-entry we’ll talk about.

Host: So you were really focused on “This is what I want to do” from a very young age. So you ended up basically following that path, even though you probably thought it was going to take you a different direction. And you ended up where you really wanted to be.

Eric Stern: Yeah, I kind of happened into a path that turned out to be a more direct route to get where I wanted to be. I kind of thought it would be pretty difficult going the fundamental science route.

Host:Right.

Eric Stern: And as it turns out, in graduate school I got hooked in with my adviser, who was very plugged in with NASA. And it was just a clear path to NASA and, in particular, Ames.

Host: That’s great.

Eric Stern: I always wanted to work here specifically. So I’m very fortunate.

Host:Yeah, that’s amazing. There were so many people out there, even when I was growing up, that thought they’d be something, and they’re complete opposites – about four or five times, even. So yeah, that’s pretty cool: that you were able to actually get in and master your plan.

Eric Stern: Yeah. And then through the Asteroid Project, it’s great because I get exposed to that planetary science and fundamental science again, even though I thought I’d be building spaceships with my education.

Host: No, that’s pretty cool. Well, okay. So you obviously did what you said you were going to do. What about you, Donovan? What are you doing now at NASA? What is the job that you’re actually working on right now?

Donovan Mathias: So most of what I do is applying computational tools to risk assessment.

Host: Oh, okay.

Donovan Mathias: And risk assessment could be human space flight. So if there’s an event on the launch vehicle as we’re sending humans to space, what do we have to do to detect that environment, that failure, and get the crew safely away? We do a lot of support of campaign missions and then, with the project we’re talking about today, the asteroid-risk assessment. So basically, my background was also computational fluid dynamics.

Host: Right.

Donovan Mathias: And we’re morphing that to answer questions as they relate to decisions involving risk, risk mitigation.

Host: Now, you mentioned asteroid-threat assessment. Right?

Donovan Mathias: Yeah. Yes.

Host: What exactly is that? And how are you both linked in that?

Donovan Mathias: So at Ames we have what we call the “Asteroid Threat Assessment Project.”

Host:Okay.

Donovan Mathias: It’s now in our fourth year. We support the Planetary Defense Coordination Office in the Planetary Science Division at NASA Headquarters as part of the science mission directorate.

Host:Wow. Okay.

Donovan Mathias: So the Planetary Defense Coordination Office, their job is to coordinate efforts among national agencies within the U.S., whether it be emergency managers or Department of Energy defense that could be involved if we detect an object that’s going to hit us. Also to represent the U.S. in the United Nations forum and coordinate international responses should there be an asteroid that is on an impact trajectory to the earth that we detect, and it is large enough that it could possibly cause damage to civilization.

Host: Already I’m starting to get a little nervous about what could happen. You guys could either assess it early or have predictions of what might occur. Is that what . . . ?

Donovan Mathias: So our project would be more about the consequences should the event happen. There are other groups within NASA that look at surveys. A lot of effort is spent into cataloguing and detecting asteroids that could potentially become hazardous that cross the earth’s orbit. There’s obviously many, many asteroids in space. We don’t worry, from a risk assessment, about many of them. A small percentage are in an earth-orbit-crossing trajectory, and so the telescopes will be looking at those to try to pick them out. So our job is to do the assessment.

Host:Okay.

Donovan Mathias: Should an object be on a trajectory that would impact, we look at its characteristics, both from a probabilistic standpoint – because a lot of times you’ll detect an object coming in and all you’ll see is a dot in the sky.

Host: Right. That’s what I think of right now.

Donovan Mathias: Right. And the dot in the sky is through a telescope. It’s not something that we would obviously see. Very, very faint. So to do the potential-risk assessment, we would need to know best guess on how big it is, how fast it’s going, how dense it is – so how heavy and massive the object would be. Once we have that information, then we have groups within our ATAP, which is the Asteroid Threat Assessment Project, that look at how likely the different characteristics are; what the entry and breakup when the object hits the atmosphere, which Eric will talk more about; how it breaks up and deposits the energy into the earth’s atmosphere.

Host:Wow.

Donovan Mathias: That energy deposited then creates things like heat and pressure waves that can cause damage on the ground. And then we bring all of that together and integrate it into how likely our different scenarios happen.

Host: And is that when the supercomputers come in to use? You mentioned simulations in CFD, computational fluid dynamics. Is that when that happens? You bring that data in and visualize it through data analysis?

Donovan Mathias: Most of the supercomputing application would be on the entry modeling.

Host:Okay.

Donovan Mathias: And then also, once we have how the energy is deposited in the atmosphere – because the asteroid comes in at a very high speed, and it slows down. And that energy has to go somewhere. And it goes into either light, heat, or pressure waves moving through the earth’s atmosphere. How that process happens, and how those pressure waves propagate to the ground, is really where we spent most of our supercomputing applications so far.

Host: Whoa. Okay. All right, Eric. Now, are you going and finding materials out in the fields of Arizona somewhere, or how do you get samples to even analyze?

Eric Stern: I wish. I hope one day I get to go on to one of those expeditions. And if we talk about Tunguska, then . . .

Host: Right.

[General laughter]

Eric Stern: But no, we acquire meteorite samples from meteorite dealers, which is . . .

Host:Cool. Okay.

Eric Stern: But yeah. So for my component, my group really gets into the weeds on the entry-modeling aspect of it. And so we’re using the same computational-fluid-dynamics tools and material-modeling tools that we use to model entry spacecraft to model meteor entry.

Host:What does that mean: “tools”? Are you cracking them open? Are you . . . What are you doing?

Eric Stern: So soft- yeah, sorry. By that I mean software.

Host: Oh, okay.

Eric Stern: Because of the specialized nature of doing spacecraft entry modeling, we’ve written all that software here at Ames. And so we’re applying that software to this new problem, which is similar in some ways but different in a lot of ways. And so most of the people that are on the Entry Modeling Team within ATAP are running simulations using this high-fidelity software that we’ve developed here.

Host: And what predictions, or at least assessments, are you looking at? Are you looking at size at entry, or trying to understand how big they could be as they approach Earth? What exactly is involved in the assessment beyond – you know, after the fact?

Eric Stern: It probably makes sense to start with when the asteroid hits the earth’s atmosphere.

Host: Right.

Eric Stern: That’s where the fun begins, so to speak.

Host: Okay.

Eric Stern: The air around the asteroid, similar to the way it would be with the spacecraft, begins to heat up. And that, in turn, causes the material to melt and vaporize. So really, the first effect that you’re trying to capture which is important to us trying to understand the risk is how the mass of the object will evolve as it passes through the atmosphere.

Host: Mm-hmm.

Eric Stern: So that’s a big focus for us: to model both the air flow around the meteor and to model the way the material reacts to the hot gas. We’ve done a lot of work on that in the Arc Jet and with simulations. And then from there, as you get deeper in the atmosphere, the pressure becomes very significant on the object, which causes it to start to break up. And that’s when the energy of the object really gets deposited in the atmosphere at a high rate. And that’s kind of where we hand off to one of the other teams that’s working on modeling the hazards.

Host:Now, you mentioned something about Arc Jet. What’s that?

Eric Stern: So NASA Ames, we’re fortunate to have a premier facility for doing – it’s essentially a very high-energy wind tunnel. And so we use that continuously – it’s probably running right now – to assess spacecraft thermal-protection-system materials.

Host:Okay.

Eric Stern: Again, these enter the atmosphere at a very high rate of speed and need to withstand a lot of heat. This is one of the only facilities where we can get close to a similar environment as you would have during entry. So we’ve actually taken that and used it to try to start to understand what happens to meteorites when they pass through the atmosphere.

Host: Mm-hmm.

Eric Stern: And so we’ve recently done some pretty unique experiments using that facility, where we placed a meteorite sample in the wind tunnel.

Host: Oh, cool.

Eric Stern: And you can see it melt and vaporize.

Host: Right.

Eric Stern: And you can kind of imagine, through those movies, what –

Host: Entry looks like.

Eric Stern: – what an actual meteor entry looks like, probably for the first time.

Host:Wow, that’s crazy. Are you talking about an actual size, you can hold it in your hand, or bigger? What size are you testing in the Arc Jet?

Eric Stern: The samples that we tested were about an inch in diameter.

Host: Oh, wow. Okay.

Eric Stern: Now, if you had an inch meteor that came into the atmosphere, it would be a pretty bright event. You could certainly see it if you were fortunate enough to be looking at the sky at that time.

Host: Really? An inch in size?

Eric Stern: Yeah. Oh yeah, yeah.

Host: That’s crazy.

Eric Stern: Usually the shooting stars that you see are on the order of millimeters or something like that.

Host: Wow.

Donovan Mathias: We are continually bombarded by –

Host: I don’t think I ever thought the size was that small.

Eric Stern: Yeah.

Host: Sorry. That’s thumbnail size. But you can see that?

Eric Stern: Size is small, velocity is very large.

Host:Is fast, yeah. That’s crazy. Wow. So in terms of the threat-assessment project, or at least the effort at NASA, where did that request come from? Is that something we came up with, or is that something that Congress or government asked us to do? How did that come about? Is there a need? Should we be worried? Is there some crazy event that we’re looking to?

Donovan Mathias: Well, let’s come back to that. That’s a good place to . . .

Host: I know, I’m like: I’m really freaking out all of a sudden.

Donovan Mathias: We are not going to send Bruce Willis to the asteroid to blow it up. We’ll come back to maybe some of the media compared to the scientific…

Host:Right, right. That might be nice to straighten out for our listeners.

Donovan Mathias: Right. So NASA has a charter given by a White House memo.

Host: Okay.

Donovan Mathias: So NASA is the lead federal agency in the U.S. –

Host: Wow.

Donovan Mathias: – to look at the potential threat and to detect the likelihood and to catalog and characterize the potential meteors.

Host: Okay.

Donovan Mathias: Other government agencies would be involved if there was an impact that was impending. But from a NASA point of view, detection and risk assessment is what we’ve been chartered to.

Host: Okay.

Donovan Mathias: So the particular ATAP project was an Ames grassroots effort.

Host: Oh?

Donovan Mathias: A team led by Jim Arnold put together the capabilities, starting with what Eric had talked about: the expertise that Ames has in human space flight, the design of re-entry systems. And the thought was to apply that more broadly to look at these interplanetary objects because a lot of the technologies and tools that Eric mentioned would be the same. So we did make a proposal to NASA Headquarters, and that basically led to the ATAP project.

Host: Wow, that’s amazing. All right.

Eric Stern: It should probably also be noted that the inception of ATAP was not long after the Chelyabinsk event which..

Host:I was going to ask about that. Is it because of that event? That really was the initiator of even a more aggressive effort because that was devastating for a lot of people, but it was also a spectacular event that the world probably hasn’t seen in the last few decades.

Donovan Mathias: Or never, because of the prevalence of dash cams on the cars during the morning commute, right.

Host: Right, right. Thank God that we had that. And then it just went viral on social media. So that’s pretty interesting. It was perfect timing, I guess.

Donovan Mathias: Well, certainly the Chelyabinsk event woke the world up again. That happens every so often.

Host: Right. Yeah.

Donovan Mathias: And I think before that, the risk perception of the public had subsided. And then with an event like Chelyabinsk, certainly it’s in people’s minds again. So I would say that didn’t directly lead to ATAP, but it certainly set the stage for the effort to start.

Host: Now, I just have a question about the actual samples or the type of materials that could be coming in, whether asteroids, I guess meteorites, comets, whatever. Are you guys looking at the composition to also determine how they burn down, if you will? Is that part of the assessment, as well – the different types of materials found in these objects – or is it not really as big of a deal?

Donovan Mathias: It is. No, that’s an important consideration, both from the mass that the object brings . . . Something like a dust ball or a lightly-packed snowball certainly wouldn’t have the potential to do damage as a piece of maybe dense stone or iron. We have the meteor crater in Arizona.

Host: Oh, yeah. That’s right.

Donovan Mathias: When you fly over, if you’re flying across the country, you can look out the window and see it. It’s enormous. And that was thought to be a mostly iron meteor that hit the ground. And it made an enormous hole.

Host:Right, right.

Donovan Mathias: So certainly the size is important, the velocity is important; but the ability of the object to withstand the forces as it comes through the atmosphere depends on its composition.

Host: Wow.

Donovan Mathias: Hard to tell when it’s in space, before it hits us. There are astronomical techniques where you can make inference about that, but most –

Host: But you never really will know until we actually have a sample?

Donovan Mathias: Unless you can visit . . . Right. There are concepts. If something was inbound – and we’re talking for large objects – the plan would be to detect with decades in advance because normally we think about the orbits crossing the earth’s orbit and getting closer and closer. So there is the potential to have a rendezvous mission, where you could actually learn a lot about the physical composition.

Host: Oh!

Donovan Mathias: And that is important, both – and to the models that Eric was talking about – how the object heats, ablates, and then when it breaks up how it deposits the energy, or if it penetrates all the way through and hits the ground and makes a crater.

Host: Now, in addition to the assessment tools you’re using, like software, are we meeting to talk about, “Okay, this is where we are. This is where we need to be”? Are there workshops or something that the geniuses at NASA are coming together in the community or collaborating on, or how does that . . . Is that something you guys work on, too, to at least report on these assessments?

Eric Stern: Yes. Donovan could probably speak to some of the engagement that we have with the Planetary Defense Coordination Office and its responsibilities. But we host pretty regularly some workshops. Most recently we hosted a workshop on the Tunguska event, which was one of the – maybe the largest energy event in recorded history.

Host:Right.

Eric Stern: And that was very productive. We got to engage with the community on that. And then once every three years or two years they have the Planetary Defense Conference –

Host: Oh, okay.

Eric Stern: – which brings together everybody from around the world. And that was last year in Tokyo. And so we tend to bring a good cohort to that conference.

Donovan Mathias: Yeah, definitely great meetings. To build on it a little bit: Inside the U.S. government, there are exercises where groups will get together from different agencies. They’re not necessarily just federal. It could be state and local responders. And the idea is to run through hypothetical scenarios.

Host: Right, okay.

Donovan Mathias: These aren’t real.

Host: What if/Then, right?

Donovan Mathias: Yeah, right. The idea is: How would the emergency managers communicate between the different levels in the government? And an example would be between federal and state. There are certain regulations to enact an emergency. They would get federal aid. A state or a municipality would get federal aid. And so let’s work out the conversations in a hypothetical sense and come up with lessons learned. So these kinds of activities do, in fact, happen.

Host: Right.

Donovan Mathias: Probably annually or maybe slightly less frequent than that.

Host: And in terms of community response or feedback, are you guys getting any of that? And does that impact or have any relationship to maybe doing these assessments in different ways? Do you get feedback from the community that’s not NASA that encourages or helps you do your job better with regard to the risk assessments?

Donovan Mathias: So the technical community or the broader –

Host:Yeah. Not general public, but these communities you’re meeting with who are workshops and things. The one in Tokyo, the meetings, what kinds of discussions or feedback are you getting?

Donovan Mathias: So as part of the Planetary Defense Conference in Tokyo, there is also a hypothetical scenario.

Host: Okay.

Donovan Mathias: A few hours at the end of each day, the different participants in the conference break into groups, and they’re assigned a role.

Host: Okay.

Donovan Mathias: And so some of them are the world decisionmakers. Some are the science community. Some are the media. And everyone has to kind of step out of their comfort zone and think from a different perspective.

Host: Be devil’s advocate, right.

Donovan Mathias: Yeah – in fact, very much. And then there are group discussions, where the science community may communicate some information. And then the decisionmakers or the media or whatever the other teams would be might have a different perspective on the events and what we should do about it.

Host: Right.

Donovan Mathias: So from those, even though it takes a lot of energy to go through a hypothetical scenario, there are key points that are identified – particularly sensitivities to different mitigation techniques. And we haven’t really talked about that. But if we did have advance warning, a decade or so, of an object that would cause regional damage if it hit the earth, there are potentials to be able to slow the asteroid down or move it a little bit so that it missed the earth. 3D space is vast.

Host: Yeah.

Donovan Mathias: And the chances of having two large objects collide is pretty remote.

Host: Right.

Donovan Mathias: And if there was that potential, then mitigation becomes an option.

Host: Now, you mentioned that. So what kinds of mitigation ideas or proposals are being brought up based on what you guys work on here?

Donovan Mathias: There’s a big range, everything from parking a small spacecraft just off of an asteroid – they call that a “gravity tractor” –

Host: Oh, wow.

Donovan Mathias: – so that the spacecraft gravity, even though it’s very small compared to the asteroid, it acts over a very long time.

Host: Right.

Donovan Mathias: And so it’s possible – theoretically possible; we’ve never done it – to move the asteroid just a little bit.

Host: Just enough to miss us.

Donovan Mathias: Just a little bit, right.

Host: Okay.

Donovan Mathias: The earth moves pretty fast – right? – in its orbit around the sun, and it’s okay if the trajectories cross. We just don’t want them to cross at the same time.

Host: Right, okay. I got you.

Donovan Mathias: So slowing it down minutes over a 10-year period or speeding it up –

Host: Can help, right.

Donovan Mathias: – is all that needs to happen to get it to miss.

Host: Now, does NASA have a mission to do any of that, or missions planned for that, or . . . ?

Donovan Mathias: We don’t have a gravity tractor per se. There are –

Host:Okay, okay. But that’s just something you could think about for future – okay.

Donovan Mathias: Right, that’s one of the concepts. Other concepts of mitigation are kinetic impactors, where we take some human-made object and impact the asteroid as fast as we can with as much momentum, again, just to nudge it. And you’re not pushing it sideways so that it misses. You’re trying to slow it down or speed it up using its own motion to try to help miss the earth.

Host: Yeah, we’re not shooting at it or . . . ?

Donovan Mathias: Well, there are also nuclear-based mitigation proposals. Obviously, a lot of issues and concerns globally about sending those kinds of devices to space.

Host: Oh, I bet. Okay.

Donovan Mathias: So there’s a range. And part of the concern and what these exercises actually get at are: What are the sensitivities globally to these kinds of activities?

Eric Stern: And a lot of it has to do, as well, with: How much time do you have?

Host: Right. That’s what I was going to say.

Eric Stern: And so the sooner you detect it, the more options you have – and probably the cleaner options that you have.

Donovan Mathias: Very critical.

Eric Stern: Yeah.

Donovan Mathias: If you only had a year’s warning, there would be no way that a gravity tractor could work, for example.

Host:Right, because we’re talking about a couple decades well, a decade minimally?

Donovan Mathias: Well, that would be . . . It depends on the size, depends on the orbit, a lot of the technical parameters on how viable the different techniques are. The point was just that there are a range of possible mitigation options. And as Eric pointed out, with reduced warning time, that option space shrinks.

Host: Yeah.

Eric Stern: And as a last resort, we evacuate the area.

Donovan Mathias: And so the good news, from an earth’s point of view, is that we have an atmosphere.

Host:Right, thank God for that. Protection, protection.

Donovan Mathias: And the atmosphere is – well, yes – both from a life-sustaining capability, but it also is very effective. We get hit by –

Host: Right. Yeah, yeah. Right. Cushions the blow a little bit.

Donovan Mathias: Tremendously. We get hit by objects every day, literally every day. Not at the size of Chelyabinsk or Tunguska. Those are definitely more on the hundred- to thousand-year timeframes. But we’re getting hit all the time, and the atmosphere creates just the light show for us. Objects that could potentially cause damage if they got to the ground are stopped very high. The other nice things: We have a lot of water, and so most of our planet is uninhabited – which means most of the impact sites would be not where we have high concentrations of people. So we’re really talking about remote events, not only the –

Host: Right, right. Very isolated.

Donovan Mathias: Yeah. And even if something was to happen, the chances that it would occur near a highly populated city are – you know, look at the globe.

Host: Even less of a…

Donovan Mathias: Exactly, yeah. And if it was in a remote area that was inhabited, you could potentially move the people outside of the impact zone. Obviously, infrastructure. But as far as loss of life, a large degree of that could probably be mitigated. Take Chelyabinsk, for example: about a thousand hospitalizations, and almost all of them were glass breakage.

Host: Yeah, that’s what I remember reading.

Donovan Mathias: So if they had warning and they had some advance notice to stay away from the windows, that number could have been reduced.

Host: But not creating asteroid-proof windows.

Donovan Mathias: There’s a lot of energy. It takes a lot of protection.

Host: Yeah, it was mostly the sound waves – right? – of the impact.

Donovan Mathias: Air pressure.

Host: Air pressure, I guess. Okay.

Donovan Mathias: Yeah. Right. It is a large sound, right.

Host: Right.

Donovan Mathias: As the object broke up . . . Eric was talking about the energy. The object slows down when it breaks up. And that energy has to go somewhere, and it goes into a sound wave. It’s a little stronger than a sound wave – closer to an explosion, perhaps.

Host: Right.

Donovan Mathias: And that pressure wave is what did most of the damage in Chelyabinsk.

Eric Stern: And for reference, the Chelyabinsk object was thought to be about 20 meters when it came in.

Host: Oh, wow.

Eric Stern: And probably no more than about a meter worth of material survived to the ground.

Host: That was found, right.

Eric Stern: So that just gives you an idea of how much that atmosphere is protecting us.

Host: Pretty remarkable. It burned off 95 percent of it.

Eric Stern: Yeah.

Host: That’s insane. Wow.

Host: So in terms of the knowledge or the results of your assessments, what does NASA plan to do with that information – I guess from your perspective, at least? And then we’ll go to Eric because his is a little – it’s very similar, but . . . What are you guys going to use that data for?

Donovan Mathias: Well, certainly these are different pieces of the integrated puzzle.

Host: Right.

Donovan Mathias: So there is a national – basically, an asteroid response plan that sets up a national strategy. And so we’re not directly involved in that so much, but we provide the risk information and sensitivities to NASA Headquarters, which is then representative in this action plan. So it’s a couple of different things from a risk perspective: informing in advance decision options, risk options; and then also telling the science community or the spacecraft community what’s important. What would we need to know about an object to be able to determine its risk?

Host: Absolutely. Right.

Donovan Mathias: And so it’s a lot of decision support in advance.

Host: Okay. And then from your perspective, Eric, what do you hope or what will be its primary benefit for the information that you’re gathering on your work?

Eric Stern: Yes. So externally, the stuff that we do, we’re kind of doing some fundamental research.

Host: Right.

Eric Stern: And so the outputs from what we’re doing has the potential to benefit the community. Other people can look at our work and try to build on that. So that’s one avenue where, I think, this NASA supported work is just supporting the community and the collective understanding of this very difficult problem.

Host: Yeah. Very challenging.

Eric Stern: And then the other benefit that we’ve realized is this is about as challenging, as you say, as entry physics can get. These are incredibly unbelievable speeds that we’re dealing with and incredible mass removal. And all of these phenomena are just like we would deal with with spacecraft but on an extreme scale. So they really stress all of our tools and all of our knowledge. And so I think we’re being forced to grow the tools and to revamp some of our understanding of some of the physics here, or to go out and seek new ways to do the physics. And that will benefit just our general capability for modeling entry, as well.

Host: Well, I think it’s commendable – to think: Wow, NASA is doing the obvious space exploration, earth science – maybe not so obvious – the aeronautics research. But asteroid detection and risk assessment? That is freaking awesome. If you think about it, you’re saving potentially millions/billions of lives by just understanding what flies through our trajectory. And not only that, but what you do today will be the stepping stone for how we can mitigate that stuff. So do you sleep at night better or worse because this responsibility is on your shoulders?

Eric Stern: Well, I certainly go to sleep at night feeling lucky that I get to work on such an interesting problem.

Host: Right.

Eric Stern: But I think, as Donovan was saying: The more you work on this, the more you appreciate how infrequent these are and how well our atmosphere has protected us from these kinds of events. So I sleep pretty well.

[General laughter]

Host: Well, I do now knowing you guys are on top of this.

Donovan Mathias: It has been a great project. It’s been a real gift to be able to work on this.

Host: Really, I think so, too.

Eric Stern: And through that community engagement, we find a lot of people that like this problem so much that they do it as a hobby –

Host: Oh, wow.

Eric Stern:– because there isn’t a lot of funding, I would say, through other means. And so I would say that they tend to be happy that NASA is investing in this –

Host: Absolutely.

Eric Stern:– and to have a project which is continually working on the problem.

Host: Well, you guys have been amazing. And I’m still looking forward to understanding a little bit more. So is there anything that you would add to this conversation to let our listeners know not to be afraid – or maybe not that, but any advice or any encouragement to what you’re working on so that it’s not something they have to worry about right now?

Donovan Mathias: There’s certainly a lot of –

Host: Hopefully. Right.

Donovan Mathias: – videos and information. There are stories out. So there are ways that anyone interested can find out more about the specific work, the simulations we do, and their NASA resources for that.

Host: Wonderful. Absolutely.

Donovan Mathias: But one thing that was told to me early on in the project is this is a natural disaster that we could potentially know about in advance and do something about –

Host: Absolutely.

Donovan Mathias: – and, arguably, the only natural disaster that we could mitigate. So put the infrequency on top of the potential to actually do something about it. It is a threat that we want to be aware of. And the ability to mitigate depends on knowing this could happen and then having some predetermined strategies for dealing with it. And so that’s really part of the effort of this project in the global/U.S. strategy.

Host: Go, NASA. That’s awesome.

Kimberly Minafra: You’ve been listening to the NASA in Silicon Valley Podcast. If you have any questions, on Twitter, we’re @NASAAmes and we’re using #NASASiliconValley. Remember we are a NASA podcast, but we aren’t the only NASA podcast, so don’t forget to check out our friends at “Houston We Have a Podcast” and there’s also “Gravity Assist” and “This Week at NASA.” If you’re a music fan, don’t forget to check out “Third Rock Radio.” The best way to capture all of the content is to subscribe to our omnibus RSS feed called “NASACasts” or visit the NASA app on iOS, Android or anywhere you find your apps.

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