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Planetary RadioNovember 1, 2019

Space Policy Edition: How a Report Can Move Mountains

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On This Episode
Jay Melosh
H. Jay Melosh

University Distinguished Professor, Purdue University

Casey Profile Picture Thumbnail
Casey Dreier

Chief Advocate & Senior Space Policy Adviser, The Planetary Society

Headshot of Mat Kaplan
Mat Kaplan

Planetary Radio Host and Producer, The Planetary Society

How can a simple report—just words on a page—lead to creation of a spacecraft? We explore how a 2019 report on the need for a dedicated, space-based telescope to find threatening near-Earth asteroids motivated NASA to pursue that very mission. We speak with Dr. Jay Melosh, planetary scientist and chair of the National Academies committee behind that report, on how it came together and how the process works behind the scenes. We also check on NASA's budget process in Congress and news from the International Astronautical Congress in Washington, D.C.

Jay Melosh

Purdue University

Jay Melosh
Jay Melosh, University Distinguished Professor, Department of Earth, Atmospheric, and Planetary Sciences, Purdue University.
Rogue's Gallery of Radar-Imaged Near-Earth Asteroids


Rogue's Gallery of Radar-Imaged Near-Earth Asteroids
TOP ROW, LEFT TO RIGHT: Near-Earth asteroids come in all shapes, from round (2005 YU55) to faceted (2017 BQ6) to lumpy (2017 CS) to very lumpy (2014 JO25). Their shapes are revealed by radar images made by bouncing radio signals off the objects when they fly past Earth. BOTTOM ROW, LEFT TO RIGHT: A surprising number of near-Earth asteroids are multiples. There are binaries (2004 BL86) and even triple asteroids (3122 Florence). Most have small moonlets orbiting bigger main bodies, but some have near-equal-size components (2017 YE5). Occasionally, the two bodies approach each other, forming a contact binary (1999 JD6).
Defending Earth

The Planetary Society / Kim Orr

Defending Earth
The Planetary Society's 5-step plan for tackling the asteroid threat.

Related Links


Mat Kaplan: Its time once again for the Space Policy Edition of Planetary Radio. I am Mat Kaplan, the host of Planetary Radio, joined by the chief advocate of the Planetary Society, that is Casey Dreier. Welcome back, Casey. It's a big day.

Casey Dreier: Yeah, it's Halloween. It's a very exciting day for me.

Mat Kaplan: And what a day, I mean as we speak, it has only been moments since the house of representatives voted, for only the third time in the history of the United States to take up impeachment proceedings against a president of the United States. And of course the big subject in all of this is space exploration.

Casey Dreier: Yeah, exactly. This is all about the space exploration policy and really taking the White House to account. No, this'll be let's say possibly driving some wedges between the parties, and also taking up quite a bit of oxygen in the room, metaphorically, that will make it difficult let's say to get our budget passed in time by November 21st, even assuming everything has kind of worked out between the two parties, and that's a priority so. We will be watching this of course, like hopefully all people, particularly us citizens. Pretty big deal. Of course, this is one of those good examples that reminds us that space policy and politics generally is along for the ride in the US congress, not really leading the show.

Mat Kaplan: Well it's going to be an interesting, well let's put it this way, an even more interesting several weeks ahead in DC. And probably space policy is not the only thing that's going to be taking the back seat for a while. There are many other things for us to talk about, and you have a terrific interview coming up that I already have gotten to listen in on. It's going to peel back how decisions get made about things like missions at NASA. It's really pretty interesting, I'll let you preview that in a moment. But first, let's give our usual encouragement to people, that if you are enjoying the Space Policy Edition, if you enjoy what we do with Planetary Radio and you're not a member of the Planetary Society, I must say I am shocked. Shocked.

Casey Dreier: Shame, shame, shame. Really.

Mat Kaplan: is the place to go to get yourself in our good graces, because we want you. We need you as a member. And you can check it out there, see what it costs, not that much. And see what the benefits are. Huge.

Casey Dreier: Yeah, I couldn't say it better, Mat. Please check it out and support the show and the incredible work that we do here at the Society. The very act of being a member demonstrates that the public supports space exploration. We take that seriously, not just because our jobs rely on it, but we answer to you because of our core values at this organization, to be that voice of the public, not just here in Washington DC, but everywhere in terms of education outreach, or projects that we do. It's just a unique organization, and I'm proud to work for it and I think most people are proud to be members of it.

Mat Kaplan: And how. I'm certainly a proud member as well. Speaking of being the voice of the people, you want to mention the day of action again.

Casey Dreier: Oh absolutely, the vox populi. Come to DC with us this February 9th and 10th. Anyone is welcome, as long as you are a US address, sorry about that it just works in the way that congress works. If you live in the United States and want to come to DC, and advocate directly to the people who represent you and tell them that space is important to you, and to really take the most effective step you can, and studies demonstrate this repeatedly that showing up in person, talking about your values for space exploration will make a difference on these issues. You can register for the day of action at You can learn all about it there, you can hear other testimonials, you can hear and see what you'd be in for, but it's a lot of fun.

Casey Dreier: It's an incredible experience to walk around the halls of Washington DC, and to again, not just be a space fan, right, you can turn into a real space advocate and do something about something you love so much. And so I hope you consider joining us this upcoming February 9th and 10th. We give you the training, we schedule your meetings, and you just kind of bring yourself and your passion and we make sure that that's heard in Washington DC, so please consider joining us in February.

Mat Kaplan: And if you're there, you get to hang out with people like Casey, like Brendan Curry, maybe even the CEO of the Planetary Society, the science guy himself, because he's an enthusiastic participant in our advocacy efforts in Washington DC.

Casey Dreier: Yeah I mean that's part of the fun, is getting to hang out with other space enthusiasts, let's say, and grabbing a drink after a long day on the hill and comparing notes, and just talking about that shared bond, right? And I'm always reminded of this when meeting with our members or getting together with people. It doesn't matter where you come from, your age. We had people last year who were six years old, and we had people last year who were in their 70s. And everyone there shared that common bond, that looking up into the stars you can see yourself, or see humanity going out there.

Casey Dreier: Whether it's through robotics, whether it's through the joy of discovery, or whether it's to save humanity, that common bond is so strong, and it reminds you at its core why we do this, right? It's to find those other people and to share that joy of that pureness of discovery and it's just that reminder that space exploration, for everything you just mentioned that's happening in Washington DC now, the partisan rancor, the divisiveness, this is the opposite of that. Space exploration brings us together in this shared goal of exploring the unknown and experience it's worth to have. It's a healthy reminder, and it's a beautiful experience and so that participation, that joy, that bond that you build with your fellow members and staff at the Planetary Society, that's one of the best reasons to attend, even if you're kind of a political skeptic.

Casey Dreier: There's value beyond the actually advocacy, and that's the community and that warm, fuzzy glow. You've helped make a difference for something you deeply care about.

Mat Kaplan: Well said, Casey, and I hope that I will get to share in that passion that you just expressed on the day of action. I keep hearing from listeners saying, "Mat, Mat, you've got to be there." And yeah I hope I will be. It's not fully determined yet, but we shall see how things go.

Casey Dreier: I guess it depends how many members sign up between now and February.

Mat Kaplan: Yes, I guess. You had yet another reason for being in Washington in the last few days, and that was IAC, the International Astronautics Congress, that you and a number of our other colleagues attended. Can you give us a little report?

Casey Dreier: Yeah this is a yearly congress, or conference, that happens all around the world. This is the first time it's been in the United States I think in maybe two decades, something along those lines, in Washington DC, for the 50th anniversary of Apollo. So it made it easier for me and some other members to go, because you didn't have to fly internationally and it's a little more accessible. Something around four, 5,000 space professionals were all there. Lots of industry representatives, lots of international representation kind of fascinating to see people from around the world coming who participate in space programs at all levels of capability. And then of course a small cadre of space policy historians, experts like myself and others. It's the entire space community, basically, in one place.

Casey Dreier: It's one of those situations where you can just wander the halls and see, oh here's a company that makes small actuators for space missions, and then next door to that would be a company that's building a new small launch vehicle. And then next to that is oh, it's Lockheed martin with the Orion spacecraft. It's like everyone from the suppliers to the major contractors to fans of space exploration were there. And all sorts of discussions, so there were talks about planetary defense, SETI, there was interesting discussions on one of my favorite topics, an interstellar probe being studied for the next heliophysics decadal survey that NASA's putting together. It really runs the gamut, and it's quite a fun process. The vice president came and opened up the ceremonies for IAC this year, and talked a lot about, as you might imagine, the Artemis program. The administrator Bridenstine was there, and I think something like he said 20 other heads of various space agencies around the world were all there as well, all getting together to talk about shared exploration, shared exploration of the moon in particular.

Casey Dreier: So it's a fun conference and I always enjoy to go to something like that, and to meet. We had great representation with Bruce Betz, our director, or chief scientist, I should say, was there talking about Light Sail. Bill Nye, our CEO, if you haven't heard, was there talking about the exploration of Europa, and planetary defense, and then other staff of course were there as well. So it was a great experience, and well worth our time to be there.

Mat Kaplan: And some big announcements made by a lot of major players, right. What about this Blue Origin Coalition that has come together to reach the moon.

Casey Dreier: The super group. The Traveling Wilburys of aerospace contractors.

Mat Kaplan: I tend to think of it as a Cream, but that dates.

Casey Dreier: Yeah, unlike the Traveling Wilburys reference, which puts me quite in the current crowd here.

Casey Dreier: This is fun, this has been kind of interesting actually over time I think this really kicked off when, a couple years ago at IAC in Guadalajara in mexico, Elon Musk announced what came to be known as the Starship project at SpaceX, and I think you're seeing a lot of company starting to see IAC as this almost like consumer electronics show, this big gathering to announce big things to get a lot of attention. So you're seeing a lot of news held until this event, to kind of capture that focus of the space community. So this was pretty fascinating, actually, in the context of how processes come together and missions come together like this.

Casey Dreier: So as most of our listeners know, NASA has an open, what's called a RFP, a request for proposals for a moon lander right now from industry. This is a fixed-price contract, this is what we talked about last year that NASA doesn't actually know how much funding it's going to have to pursue this contract, but there's an open call for industry to submit ideas to NASA to how to land on the moon in 2024. Blue Origin had announced I think the other year that it's been secretly working on a lunar lander, a cargo lander, for years. Then you have of course many other prime contractors like Lockheed Martin, Boeing, and SpaceS all with various capabilities and design, that we all assume to be putting in a proposal to land on the moon within this NASA constraint and so forth.

Casey Dreier: NASA then takes all these proposals and selects one, maybe two, of them to continue study, to develop before we're like committing in a few years. That's generally how these proposal processes work. So it's interesting to see that instead of competing, Blue Origin organized this super group coalition of industry, space corporations to put in a combined proposal. So they're not competing against each other anymore, they're competing basically against everyone else. They're bringing together all of their relevant strengths. And so this is made up of Blue Origin, Lockheed Martin, Northrop Grumman, and then Draper Industries, I believe.

Casey Dreier: These four companies each brings a relevant strength. So Blue Origin says they're gonna build the lander part, the actual cargo lander variant that can carry humans that they've been working on for years. Lockheed martin will develop, I believe, the ascent vehicle, or the crew hab vehicle, I should say. And then Northrop Grumman will have this the transfer back and forth to the gateway. So Lockheed Martin's going to leverage its investments on Orion to build the life support systems and the crew hab area. Northrop Grumman will leverage it's existing work on the Cygnus cargo transport to the International Space Station. And then Draper is the same company that build the Apollo guidance computer way back in the day. They are going to be doing the software and guidance and navigation system integration.

Casey Dreier: So it's, on paper, a very solid set of companies with a ton of experience and resources. Don't forget, NASA's looking at this as a fixed price contract. They're looking for companies to put in some of their own resources, in addition to NASA resources, so these companies have skin in the game, so to speak. It's almost certain we don't know this for sure, but it's almost certain to me that Blue Origin and others are going to be able to commit a significant amount of their own resources to this effort, in addition to what NASA pays them. So it's not used to carving up the cake way, this is unusual to have this many companies working together. It's an incredible amount of probably internal debate and organization that had to happen for this. And it has to happen very quickly. This proposal window that NASA has is open for approximately five weeks. Not that much time to put together this four company, three part lunar landing system.

Mat Kaplan: That's putting it mildly.

Casey Dreier: Yeah, I mean they had a little more time, this was telegraphed for a long time. They had some feedback opportunity, so this isn't coming out of nowhere. But it's interesting to see people motivated... In a sense, this is really good argument for why deadlines are useful in space exploration. It really drives consensus. If you are really trying to hit this date, you don't have the luxury to have 20 companies kind of fight it all out for a single contract, because they know there's time to spare, they have something just indefinitely down the line. You just want to get the biggest contract you can to feed off it for a while. If you're really trying to hit a 2024 deadline, some of that competition will have to go out the window and you can say look, we can actually take all of our best pieces of these relative companies, put them together, and that has the best chance of making it. It's the quickest way we can all leverage our capabilities to get a piece of this action, and to really advance this capability forward.

Casey Dreier: So there's a lot of debate going on right now about the value of this 2024 deadline. Why not just keep it to 2028 or so forth and so on, and I think we're really seeing again how deadlines are a clarifying force and function for a lot of the process stuff that has to happen through government procurement contracting, things that are written into the law that helps move things forward maybe in a more linear path than you would see otherwise.

Mat Kaplan: In a previous life, I started a saying, which I think lives on in that previous life, that previous location. Deadlines are magic.

Casey Dreier: They certainly again help clarify the process. They're a consensus driver, at some point.

Mat Kaplan: This is a tall order. I mean you have competing cultures here. You have competitors, basically. Lockheed Martin and Northrop Grumman in the same project together, there are lots of ways this could go south, I suppose, but it certainly is impressive that this coalition has come together. Let's go up the street in DC from the International Astronautical Congress to Capitol Hill and what is happening there. I know there have been complaints that as we enter once again this era of continuing resolutions, the Artemis program to reach the moon and other components of space exploration, space development, are maybe not getting the attention that they might, but then neither are a lot of other programs.

Casey Dreier: That's certainly true, and we'll just touch on two major events that happened since our last episode. So last episode, we talked about the new fiscal year began on October 1st. NASA is under a continuing resolution so extending the previous year's budget through November 21st right now. So nothing can start at NASA, but nothing can end. So it's basically again just kind of this extension of previous years appropriations. The two things that happened are related, and both are not super positive for this deadline.

Casey Dreier: The first one was that the house, the democratic led house of representatives, they held a hearing in the CJS, the Commerce Justice Science subcommittee, that's the subcommittee that writes NASA's budget, the 2020 budget, and the house version. They already passed the budget for this year, but they're are negotiations with the senate right now about this, they have to reach some sort of consensus legislation for funding NASA next year. So they have a lot to say, because they give no money for the Artemis program. So they held a hearing on the Artemis program with the administrator, Bridenstine, the associate administrator of human space flight, and they sounded quite skeptical, generally, at least the leadership.

Casey Dreier: In the house the leadership, which was the democrats right now, they have significant control over the entire process in a way that even in the senate the minority has more ability to influence the process. In the house, that doesn't exist. So the majority in the house of representatives has significant control over the entire process, over the final bill and that negotiation. Jose Serrano who is the chair of this committee repeatedly expressed his skepticism and confusion of why do we need to land in 2024. He didn't feel NASA or the White House has made that rational clear and he was worried about the cost because he kept saying we don't know how much it will cost, so why should we pay up the money now to get it started on the lunar lander.

Casey Dreier: These aren't wrong, right? These are good questions.

Mat Kaplan: It's what congress is supposed to consider.

Casey Dreier: It's what they're supposed to do, they're representing the public tax payer in a sense, right. They're trying to be good stewards of the taxpayer money. There are reasons for 2024, but I think it does show that the 2024 deadline it's obviously connected to the last year of a second term of a Trump presidency. It's hard pressed to kind of add on other reasons for it, and so the democratic party that runs the house isn't going to be super excited for that being the motivation. And so it's not NASA's fault, it's the White House I don't think has clearly given good reasons, has clearly explained themselves for any reason beyond that. And they're kind of leaving NASA in a sense a little bit to twist in the wind, to say here's this deadline that you have to follow because you're an executive branch agency, but we're not going to give you a ton of help on making this happen.

Casey Dreier: So Jim Bridenstine's doing the best he can, and the best argument that we kind of touched on earlier is that this 2024 deadline reduces political risk, which is true. Assuming there is a second term, even the near term aspect of a 2024 deadline, you condense the political support for an Artemis program down to a single presidency, theoretically, versus this open ended long-term multi-decade commitment that spans multiple presidencies, which almost certainly will never happen, because you can't count on the political support of a future undetermined White House.

Casey Dreier: That is a good argument, but it's a process argument. It still doesn't express the fundamental why do we need to be at the moon by 2024. And there may not be a good reason for that, honestly, beyond that it's a useful thing to do to speed things up. You see a fundamental hesitation and weariness by the democratic controlled house of representatives, at least on this committee, to really go all in on a program that'll cost something like 20 to 30 billion dollars above what they were already planning to give NASA over the next few years. Obviously, that raises a lot of concerns about what happens to other science programs, other missions at NASA, and Bridenstine, again, has been very smart in saying that we don't want to cannibalize anything internally. This has to be new money. But at the same time, maybe the White House could've chosen earlier, back when they had a republican controlled house of representatives to kick this off. But they didn't, and so they're kind of stuck in this much more skeptical house.

Casey Dreier: And so that hearing happened, did not bode well. They're generally still supportive, right, I mean the house still gave NASA a boost this year, just not for those priorities. The other important thing that happened was Richard Shelby, who runs appropriations in the senate, the senate side, said that he's expecting to have another CR, that they're not going to be able to wrap up these bills by November 21s, the current expiration. He anticipates another continuing resolution through perhaps February or march. So that would be a functionally a five to six month, half the year continuing resolution for NASA. Better than being shut down, however definitely doesn't help you get to the moon, because you don't have any funding. You can't start any extra funding for Artemis at that point. That situation would certainly spell the end of 2024 as a feasible deadline even though it's already relatively infeasible.

Casey Dreier: And so that's not a great news either, and we may see some progress, that may be some sort of telegraphing statement where he's kind of putting out the worst case scenario to drive people to take action now, we just don't know. The only public data points that we have are not what you would want to have, if you wanted a 2024 moon landing. These data points in the last month don't support that deadline very well and so we're continually looking for this. We will see in the next month whether congress will go through with that deadline on the 21st. Whether we'll get another CR, or whether they can get their act together and pass a few of the appropriation bills in time, but it's going to be quite a show as we get there, for all the reasons not just that I mentioned, but the fact that we brought up at the beginning of the show that there is the whole impeachment inquiry and ultimately a trial that is going to have to happen at the senate at some point.

Casey Dreier: So it's a lot going on and none of that really is what you want for a steady political process to fund something as complex as a lunar program.

Mat Kaplan: Always interesting times in the capital of the United States. But of course that's not the only place. Congress is not the only place where decisions are made that help to steer the future of space exploration, at least within the United States. And what I'm doing here is trying to come up with a segue into [crosstalk 00:23:32] this terrific conversation.

Casey Dreier: I'd say it's pretty good. Yeah, that's a good segue. Let's talk about how things are supposed to work, right, and how ideal case situations work. This is about planetary defense. Exploring how we got to this situation where now NASAs going to commit to a near earth object space telescope in the infrared to search for these near earth objects. We talked about this in the last episode a decent amount. About how we need one of these space telescopes. Why planetary defense is important that we have this big public support for planetary defense, but NASA hadn't been able to find a place to slot in a mission dedicated to finding near earth objects within its existing portfolio. Just because its existing structures and bureaucracies were all focused on NASA's big core enterprise in science, human space flight, technology development and so forth. Aviation.

Casey Dreier: How did we get to this point, what did it take for NASA to change its mind, or for key people at NASA to change their minds and embrace a space telescope that can do science, but its primary mission is going to be planetary defense? The key, sometimes, but tends to be a lot in NASA history, is a report. And I promise this is more interesting than it sounds, but the idea of building some sort of externally respected, and broadly respected, consensus statement hat anyone can point to whether you're inside of NASA trying to build your bureaucratic footprint, or outside of NASA trying to justify funding, like if you were in congress, having this kind of one single report that states clearly that this is a valuable use of public funding, it's scientifically grounded. It will do the job its goal is to do. Even that is sometimes just important to be reminded of, that there's experts validate the concept.

Casey Dreier: This is the value of a report, particularly from the National Academies of Sciences. And its job is to provide independent scientific analysis to congress. I wanted to talk to the chair of the committee that wrote this report that lead to NASA at least initially embracing this concept of a planetary defense mission flight line, and NEO surveillance mission. And understanding how a report like that comes together, what people participate on it, the process of that, and then how you get to something like NEO surveillance mission, from this process that builds upon literally over a century of trust. It's kind of a big burden to carry on, that you're maintaining that respectability. That's the only power these reports have, is that they're respected. They don't have the ability to force people to do anything.

Casey Dreier: Understanding how you get to a mission from this ongoing process that requires this sort of community and consensus building, is really enlightening particularly on the science side of NASA to say how to do we do this in the future. If we want to try to make NASA doing something new, or embrace this new type of mission, the role of these reports can be extremely important. And it's fascinating to see how something like this comes together.

Mat Kaplan: Tell us about your guest who, as I listened to you and him talk very recently, I got the impression that this was the kind of guy I wish had been one of my professors.

Casey Dreier: Yeah. Jay Melosh, he's a distinguished professor. He's a professor at Purdue in Indiana, and he's a planetary scientist. Long experience in asteroids and meteorites. He's also a member of the National Academy, so about as high of a very respectable... it's a small club, let's say.

Mat Kaplan: Highest accolade, pretty much for [crosstalk 00:27:31]

Casey Dreier: Very high accolade, yeah. Variety of medals and... received performance medals, and academic quality. Tons of paper, just an expert in his field. The National Academies tries to find people who are experts in the field, but not directly involved in it. He wouldn't himself benefit from the existence of a space-based IR mission. An expert, but independent, but Jay Melosh again, professor of department of earth atmospheric and planetary sciences at Purdue University. I think he's been there at least 30 years or so. He walks us through this process, and you can see again his communication ability, but also his deep familiarity with this field. About how you put together this sort of report with this committee, because it's not just him writing this, right, it's a group of people who have to reach a consensus themselves before writing this report.

Mat Kaplan: So here's that peek behind the scenes. A very important process, a very important part of the process that determines how we move forward in space science, space research. It's Casey talking with Jay Melosh just a few days ago. Here we go.

Casey Dreier: Dr. Melosh, I want to thank you for joining me today at the space policy edition.

Jay Melosh: It's a pleasure to be here.

Casey Dreier: In addition to being professor at Purdue University, you in this case, what we're interested in talking about, you chaired a committee, and I really like the name of this committee, and I actually had to write it down to remember this. You were the chair of the committee on near earth object observations in the infrared and visible wavelengths. Now, that strikes me as a very specific committee, and I assume this did not exist before you began to chair it. Can you give me the context of how you came to chair something so specific, and what purpose this committee was formed to solve.

Jay Melosh: Well this was a committee of the National Research Council, which is part of the National Academy of Sciences. The National Academy of Science's purpose is to be an advisor to the nation on scientific issues. The way that the national academy does that in large part, is by taking commissions, do reports on particular topics and put together a, as far as possible, unbiased panel to give the best expert advice to the nation on whatever issue it is, whether it be something about diesel truck emissions, and in fact most of the reports do deal with transportation, or whether something like defending the earth from threatening asteroids. In this case, we were actually commissioned to do this by a request from NASA, it came from, I think, Jim Green, who made a three point request for us to specifically to look into this issue of the best way of finding asteroids that are threatening the earth as quickly as possible in large part to satisfy the requirements of the 2005 George E. Brown amendment.

Casey Dreier: What was that 2005 policy that you just referenced?

Jay Melosh: The amendment required NASA to find all of the, well 90% or more of the objects threatening the earth greater than 140 meters in diameter by 2020, and although the amendment was passed, there was no appropriation passed at the same time, and as a result there was not a major result by NASA to go ahead and fulfill the requirements of the amendment. My opinion is that this was brought up at the current time because NASA is getting a little worried that congress may notice that they haven't actually fulfilled the terms of the amendment, and that NASA ought to be doing something about it.

Jay Melosh: Now, NASA has actually been doing something in the meantime. They've established an Office of Near Earth Asteroids headed by Lindley Johnson, so NASA hasn't been entirely unresponsive, but the possibility of finding 90% of all these relatively small asteroids by 2020 is receding. In fact, we don't think that NASA can do it by next year, but it is possible to do it within a relatively short time, and that's what this report was about, was how to do that most expeditiously.

Casey Dreier: Let's start with the first thing, which is it's 2019 and NASA asks the National Academies for a report saying hey, what's the fastest way to address this congressional mandate next year. Just to be really clear, is there any physical possible way to actually meet that mandate by next year, from what NASA has already done in terms of finding these small asteroids?

Jay Melosh: Given what we heard in testimony, and what the experts on the panel concluded, I think the answer's no.

Casey Dreier: Given the fact that NASA's asking the National Academy for this, you are a member of the National Academies. How did you in particular get assigned as the chair of this committee? Do they just come to you and find you, or do you raise your hand, is there some broad call. How does that process work of assembling this community and how did you end up chairing it?

Jay Melosh: Well the simple answer is I was asked to chair the committee, but the context of this is I have been on a number of other committees before, dealing with different parts of NASA. I was on the 2010, we produced a report called Defending Planet Earth. I was not chair of that committee, but I was a member of it. And I've also been a member of a number of other committees dealing with NASA technology, and trying to understand what kind of technological developments NASA needs to do to fulfill its mission. So I'm not completely naïve about these sorts of panels. It is the first time I've ever chaired one, and I'm grateful for the opportunity to do that, but although I did chair the panel I have to say we had a great group of people on the panel, most of whom were more expert in this particular area than I am. I am not an astronomer, I am a theoretician that studies meteorite impacts, and the consequences of meteorite impacts on the earth.

Jay Melosh: So the panel contained a number of other people who were very expert, both in optical astronomy, ground-based astronomy, as well as space based astronomy.

Casey Dreier: What was the process of putting that report together? Do you sit all together in a room and write it together, do you just have all ideas you bring from previous experience, or do you do fact finding? Walk us through this process a little bit of how this comes together.

Jay Melosh: A total of four physical meetings where the panel was all present starting out with a kickoff meeting in Washington DC where we all got together. But even before that, the way these panels work the National Research Council selects someone to oversee the report, in this case it was Dwayne Day, he then with his staff assembled a group of people, and the requirements for the membership of the committee are it should be broadly representative in the area, for example, in addition to experts on astronomy, we also had some policy experts. They should be as unbiased as possible. In fact, when the process starts there's kind of a rigorous confession of what all prejudices you might have, what your interests are, and so on.

Jay Melosh: If you do have any conflicting interest, for example, we couldn't have anyone who actually worked at NASA aboard the committee, but that committee was very carefully selected and put together to be as representative as possible, with as much expertise in the area that our charge covered as possible. People that didn't have axes to grind, or at least axes that were unknown to the rest of the committee. After that first meeting we had writing assignments, and we quickly put together an outline of what we though the report would be. People were given definite writing assignments, so there was a lot of homework as well as the meeting.

Jay Melosh: And there were a total of four different meetings occurred as the report evolved. In addition to our meeting together and writing the report, we also heard testimony from different experts. We were allowed to ask people to come and address our committee about different concerns. For example, we had presentations on the NEOcam program that was going forward from Amy Mainzer who's directing that program. We also had presentations by people that had new technologies that were not really at the level of implementing them, but that might be able to address the asteroid detection problem in a better way than we knew how to do at the present time. So we tried to cover all the bases in that respect.

Jay Melosh: The report was actually on a pretty short timeline. We started our first meeting in November, and the report was ready by June. That is not typical of these reports. Usually it takes quite a bit more time. And so we were really hustling to try to get this out the door, and get it to NASA, which had requested it rather urgently. I think there was some internal thinking about what was going, which I'm not party to. They wanted an opinion from the National Research Council in order to bolster their internal thinking.

Casey Dreier: What do you see as the role of these types of reports and the value, from your perspective and the national academies. Why are these reports preferred over individual opinions, or committee statements from a variety of advisory councils to NASA. What gives these that extra oomph?

Jay Melosh: Well the reports by the National Academy have the reputation of being, not only expert, but unbiased, and the best available information. So congress gives a lot of weight to these reports, and often the way something can be made to happen with congress is to have a report. Congress, as I am told, really trusts these reports more than most other such reports that might come out of partisan agencies. With that backing and that reputation, producing a report of this kind really has a quite a bit of weight with congress.

Casey Dreier: How do you approach that then, as chair, that must be a lot of you're kind of carrying in a sense that responsibility to provide something that carries in that tradition of being unbiased and helpful and reliable. How do you approach that in a sense, is that responsibility, how do you carry that on your shoulders in this case?

Jay Melosh: Well, it's a lot of responsibility but on the other hand, the National Research Council has some people who are very expert in this, who are a great help. The staff there is used to doing this sort of thing, they have their own internal rules, which are pretty strict and they are overseen by a number of monitors. I should also say that once a report is done, it's also sent out to a large group of referees who are also expert. They really run over the report, in fact our 70 page report garnered something like 200 pages of comments from the referees, and we are required to address all of those issues that they might have.

Jay Melosh: Again, a way of checking with the wider community that what we said is correct, and represents the best scientific opinion at the present time. Yeah it was a lot of responsibility, but I also had a terrific group of people on the panel. I think together we produced a pretty good report.

Casey Dreier: I agree, I really enjoyed reading it. And we'll get to the specifics here in a second. It just really strikes me, hearing you describe this, how much of this process depends upon reputation and trust. From congress, from NASA, and from the larger community, the scientific community, that this process is basically accepted as relatively unbiased, and the outcomes are going to be free from obvious, not just partisan, but motivated thinking. There's no real external body that can enforce it one way or another, it's just that the attitudes that everyone brings to these panels, that respect for that process that you brought and your panelists brought, and also the respect from the staff. So much of this, I think, process of science sometimes just really depends on this reputational element that's hard to otherwise define.

Jay Melosh: Well that is the role of the National Academy. They were founded, I think it's 1859. Abraham Lincoln was the president at the time, as an academy of experts to advise the nation. In that respect, the National Academy of Sciences is different from any other scientific organization. I mean, there's the Royal Society in England, almost every country has a scientific honorary society. But what makes the National Academy of Sciences different from all of those, is that it has the responsibility of advising congress on scientific issues, and it's taken that responsibility pretty seriously. The National Academy plays a role because it is unbiased and its past reports have been effective in guiding policy. Based on that reputation of past success, I think that is what gives it a lot of respect that it receives right now from congress.

Jay Melosh: Now these reports are not really intended for congressmen to read. It would be wonderful if they did, but the real aim of most of these reports, and the level at which they're written, is intended to be read by congressional staffers, who can then advise their congress people of the conclusions of the academy.

Casey Dreier: Yeah I was just going to ask who that audience was, and so you're writing educated people, but not experts, basically in the field. Would that be a way of putting it correctly?

Jay Melosh: Yeah, that's correct. But I have to say I have a lot of respect for the staffers that I've met, and they're not all expert in this area, but we have in mind as we're writing the report to be as helpful as we could in their ability to grasp the issue that we're dealing with.

Casey Dreier: And I would say, just from my perspective, I found the report very useful in terms of the technical mathematical discussions that were included in it, that helped me understand the fundamental arguments for why we need a space-based infrared system to find and characterize near earth objects. So I encourage actually anyone listening to this, and it's worth a read. And you can just read the executive summary aspect, but I recommend reading the entire report. You really see how the thinking moves through, and you can get a really deep understanding of this topic. I would say it puts you probably in the top .01 percentile of experts in the world, after reading this paper of really getting down to why it's important to find near earth objects and why we need infrared to find them.

Jay Melosh: Well that was our charge, so thank you for telling me that we, at least in some level, have fulfilled that charge.

Casey Dreier: Yeah, well let's talk about the report itself now, and maybe before we even get into the recommendations and findings from it, let's give some context for where you were coming from on the committee. We talked a little bit about the charge for finding NEOs, but what is the current context in terms of NASA finding near earth objects, and also just maybe even step back a second and say why are these important to find. What are we trying to even find out there?

Jay Melosh: Well, as a professor I'm going to maybe go into professor mode for a little bit.

Casey Dreier: Okay.

Jay Melosh: And step back into the history, if you'll allow me to do that.

Casey Dreier: Please.

Jay Melosh: Understanding of the important role of impacts to the earth and populations of the earth is a relatively new development. Up until even the 1950s, most astronomers felt that the craters on the moon were volcanic. No one paid very much attention to extra terrestrial objects. Geologists rejected the idea, because well that's hardly geology, extra terrestrial things. And very few structures were known on earth that had anything to do with large rocks from the sky falling on the earth and causing some devastation.

Jay Melosh: The Apollo missions actually changed quite a bit of our understanding of the moon. Now, there were many scientists, even before the Apollo missions, Gene Shoemaker's one of the patron saints of impact studies who was working on this in the 1950s. But the Apollo missions really made it clear that the face of the moon is scarred almost entirely by impacts. Almost everything you look at on the surface of the moon has been affected by asteroid impacts and that creates the whole landscape.

Jay Melosh: Now we don't have landscapes like that on earth because we have other processes like rainfall and, well mainly rainfall. Wind to some extent erases the records of past ancient impacts. But in the meantime, we've recognized that there are impact craters on earth. There are about 200 known at the present time. Relatively large craters. Many people may be familiar with Meteor Crater in Arizona, which is one of the most recent, and one of the most small craters that we're aware of.

Jay Melosh: But the other factor coming into this is the 1980 discovery by the Alvarezs that the extinction that killed off the dinosaurs was almost certainly mediated by a large impact on the earth, and I think as that idea kind of processed through the system, it's been recognized that large meteorite impacts do occur. They are inevitable, they've occurred in the past, they will occur in the future. With that kind of understanding, a number of astronomers, a guy named Tom Gehrels at University of Arizona was one of the first, became concerned that yeah, well there are a lot of those asteroids out there. If you start plotting their orbits relative to the earth's orbit, a lot of them cross the earth's orbit.

Jay Melosh: If you do modern plots of earth crossing asteroids, their orbits versus the earth's orbit, it looks like we live in a shooting gallery. Fortunately the earth is relatively small on the scale of the solar system, and these asteroids are even smaller, so it isn't terribly frequently that a big asteroid hits us, but it does hit. After the 2013 Chelyabinsk fireball that caused some devastation fortunately no fatalities in Siberia, it's becoming more and more clear that there are a lot of those objects out there. Modern civilization is a lot more fragile than kind of the prehuman earth was. We are vulnerable to impacts of this kind.

Jay Melosh: Within that context, there is a lot of interest now in finding where's the next one coming. We've seen a number of asteroids that have made close passes to the earth. Of course smaller ones hit all the time. One of the important facts to remember about these impacts and asteroids, is that although there are number of big asteroids, as you go down in size there are more and more of them. Roughly, it goes like the inverse size squared, so that you say you have some number, let's say 1,000 which is about the right number of one kilometer asteroids. If you went down to half that size, five hundred meters, there would be not 2,000 of them, but 4,000 of them. And similarly down the scale. When you get down to meter size objects well about one of those a day hits the earth. Fortunately our atmosphere screens most of those.

Jay Melosh: The big question, though, is what about the intermediate sizes. What about hundreds of meters up to kilometers in scale? The kilometer size has already been dealt with, with a number of surveys, many of them kind of ad hoc. Tom Gehrel's survey was one of them that he started in Arizona. But we now understand that there are about 1,000, well maybe 1,200 to be more precise, objects that cross the earths orbit that are one kilometer in diameter or larger.

Jay Melosh: The impact of an object like that would make a crater about 10 kilometers across. The studies suggest that the results of that on climate and so on could cause continent wide crop failures, or even possibly global crop failures. Although we've been hit by a fair number of 10 kilometer craters in geologic history, the human civilization is very vulnerable, that a global crop failure for a year or two would really devastate the population. Thousands of people, well, billions of people would die of starvation we don't have that much food stored as a civilization and if transportation networks break down, the food that we have stored couldn't get to those people that need it.

Jay Melosh: An impact of that kind would be really quite devastating and that prompted astronomers, even without the Brown amendment, to go to work and we think we've found more than 90% of the earth-crossing asteroids, and the good news is there's nothing target on us right now. We do know, though, that we are hit by an object of that size about once every million years, so if you ask what's the chance of an impact of a one kilometer object next year, it's one in a million. If you ask 100 years, well we're talking more one in ten thousand. We can do better than that though, and have done better than that, by tracking the orbits, and we can say well such and such an asteroid might make a close pass or might possibly impact the earth maybe 1,000 years in the future.

Jay Melosh: There's nothing that we know of that is imminent, and now as a result of the concern within NASA, the Jet Propulsion Laboratory has a wonderful website that you can go to that actually lists all of those potentially hazardous objects. Tells you what their orbits are, their sizes as far as we know, and so on. So you can get an overview just by going to the web and to the Jet Propulsion Laboratory near earth asteroid website and finding out what's known. The problem comes with the smaller objects, a hundred meter object or something like that would create a meteor crater sized hole in the ground, or maybe a big explosion like the Tunguska 1908 explosion in Siberia. Wouldn't devastate the world, but it would devastate a pretty large area if it impacted on the continent.

Jay Melosh: And of course, everyone's favorite graphic is to take Tunguska and superimpose that on a city. Washington DC is one of the favorites, or Los Angeles, or London or some other city in the world. We in fact, in our report, decided to use a graphic of that kind. Cities don't occupy a huge fraction of the earth's area, at least not yet. Nevertheless, an impact of a hundred meter sized object in the area of a city, let's say Chicago, which is close to me now, would kill tens of millions of people. We worry about nuclear weapons, and talk about very large nuclear weapons with yields of 20 megatons. Well, 20 megatons is small potatoes for an impactor of the size we're talking about. We're talking hundreds of megatons. These things, when they occur, fortunately they're rare, but when they occur they can be really devastating.

Casey Dreier: So given this obvious threat, NASA's falling all over itself to fund as much survey opportunities as possible to find these, is that correct?

Jay Melosh: That's correct. A lot of the surveys are now supported, at least in part, by NASA.

Casey Dreier: But it took a while. I like the history that you were developing here throughout the '80s. This is within basically the last generation that scientific understanding of these has gotten to a point where this is an actual issue to deal with, and we can actually begin to look for them in a systematic way. There was no awareness of this in the 19th century, or the 18th century. From a policy perspective, I'm fascinated that there's no obviously a constitutional carve out for saying here's how the nation defends itself against asteroid impacts, right?

Casey Dreier: This is a very new thing that we've had to deal with and figure out who is responsible for finding these within our federal government, and in an international framework, and we're still kind of working through that which is why we have reports like yours coming out.

Jay Melosh: That's right, it started out as very much a grassroots concern but people like Gene Shoemaker, astronomers like Tom Gehrels, who were aware of the hazard and largely on their own initiative, started a survey. But the general understanding that impacts have played actually a role on earth's history, in particular causing extinctions, that has made people more aware that there is a hazard to be dealt with. Actually, in the 18th century there were concerns, not about asteroid impacts, but cometary impacts. It's past history, maybe I'm too much in professor mode to talk about that, but it was thought, or well it was known at the time from spectro that there is cyanide in the tail of comets. And there had been a concern, every time there was a close pass of a comet that the earth will pass through the tail and we'll all be poisoned. In fact there's some Conan Doyle stories about incidents like that. So it isn't that people weren't concerned, but they were concerned about the wrong thing. Comets are probably a very, very small hazard compared to asteroids.

Casey Dreier: And we don't need to worry about cyanide in their tails.

Jay Melosh: That's right, there's too little of it.

Casey Dreier: Good. We wouldn't have been able to do much in the 19th century about it anyway.

Jay Melosh: That's correct.

Casey Dreier: So you have this development of understanding of that there's a population of objects orbiting the sun that occasionally can cross the orbit of the earth. These become potentially hazardous, so you need to find them. And so we, the scientists and astronomers, have found a lot of the larger ones, the one kilometer ones. You were talking about these mid-size, regionally destructive, city destructive impactors. Why have those not been found in the same rate that we've been finding these larger kilometer-sized asteroids?

Jay Melosh: Well the smaller asteroids, a few of them have been found of course, but first of all there are a lot more of them than there are the bigger objects. And because they're smaller, they're harder to see. The best place to see an asteroid, at least from ground-based astronomy with visible telescopes, is when it's exactly opposite the earth from the sun. Basically, looking straight up at midnight. You would be able to see objects that are illuminated like the full moon. As everybody's aware, the full moon is very much brighter than the moon at any other phase, because it's fully illuminated and the sunlight is primarily scattered directly backwards.

Jay Melosh: Astronomers call this the opposition scenario. Smaller objects are best discovered at opposition. If you're an asteroid hunter, you're best looking directly away from the sun trying to find these things when they're very bright. The trouble is that most of the time they spend not exactly opposite the earth, but in other parts of the solar system where they're only partly illuminated by the sun from our perspective, and they may be far away from the earth and so they're too faint for a telescope to see.

Jay Melosh: Astronomers have a way of measuring the brightness of an object with a scale called magnitude. It's a little bit of an inverse scale in the sense that a larger magnitude means it's fainter. So really we should call it the faintness scale. And current telescopes can find things on this scale of absolute magnitude, it's called, as faint as about 26. But there are many objects that are more faint than that that we simply can't see. They are not bright enough in a telescope, not bright enough against the sky background to actually pick out and recognize as something other than a flicker of light caused by a passing airplane, or something like that.

Jay Melosh: So the essence of finding these things is to try to find them when they are at their brightest, and at their closest pass to the earth.

Casey Dreier: So given this, we have this congressional mandate passed in 2005, that says, I kind of chose, and I don't know if you would agree it is an arbitrary size limit of 140 meters in diameter, or where does that come from in terms of that size?

Jay Melosh: Well, that's a good question. It's one that we all asked. I've been asking that for years. The Brown amendment says greater than 140 meters. It initially doesn't make any sense. It's not a conversion factor from metric. Where does it come from? One of the things we did on our committee, it's not on our charge, and we didn't spend that much time on it, but all of us had heard the number 140 meters, none of knew where it came from, and so one of the little side projects that we did is we investigated where that number came from, and I think we found the answer.

Jay Melosh: I was going to include it in the report, in fact I'm sort of proud that we had smoked it out. I wrote that part of the report, put it in the report, and then one of our referees pointed out that without actual documentation of this, legally it's hearsay and so we had to erase it from the report. But your podcast gives me a chance to tell you where 140 meters comes from, at least in our best opinion. It comes from the fact that in 2005, the best telescopes could reach an absolute magnitude of 20. We're doing better now with bigger telescopes. Also, at the time, it was thought that the average intrinsic brightness, now asteroids come in dark colors, they come in light colors. They reflect different amounts of light. Actually, as we've learned in the meantime, there are a lot more dark ones than bright ones. But it was felt at the time that the average amount of light reflected is about 15%. And if you put together a 15% light reflection ability, and an absolute magnitude of 20, you get voila, 140 meters.

Jay Melosh: So we think that's where it comes from.

Casey Dreier: Yeah, because a 139 meter is still a pretty bad day.

Jay Melosh: Yeah, that's right.

Casey Dreier: So it's functionally a consequence of the physical limitations, and scientific understanding at the time that it was written to find most asteroids, effectively.

Jay Melosh: That's right. It was felt that it would be possible with an asteroid of that brightness, over a period of time, to find 90% of them. Remember that since you can only detect asteroids when they're close, and when they're at opposition, many asteroids simply escaped detection because they're in different parts of the solar system, or they're not illuminated well enough from the point of view of the earth.

Jay Melosh: And so it takes some period of time of observing asteroids until they finally drift into view, and we can find them, and once we've recognized them get a good orbit on them so we can predict where they will be in the future.

Casey Dreier: Let's actually take this opportunity to start mentioning a few of the recommendations from the report that start to tie in here very relevantly. I'm going to choose the first one here saying, so this is from the report, this is a formal recommendation that your committee made. In reference to this, the George Brown survey so you said, if the completeness and size requirements are to be accomplished in a timely fashion, in roughly the next ten years, your report recommends that NASA should fund a dedicated space-based infrared survey telescope.

Casey Dreier: Now, given what we were just talking about, the fact that the congressional mandate was made at a time assuming ground-based observation capability, why do we need a space-based telescope to address this mandate, when it was written for ground based telescopes and one the limitations therefore of these ground based observations that drive this recommendation?

Jay Melosh: Well I think even the time of the Brown amendment it was recognized that infrared observations were better, but it was not recognized that while the technology of doing infrared observations has gotten a lot better in the time since 2005. The point of infrared is that objects in visible reflect only a fraction of the light. In the infrared, what you're doing is your sensing the temperature of the body, and in fact an asteroid that is very dark from the visible simply that it's dark, it absorbs all of the sunlight so it's warmer in fact. So where visible observations fall down, infrared picks up and they actually make a virtue out of the darkness of dark asteroids.

Jay Melosh: Infrared, in all respects, is better than optical. Ground-based telescopes also have the limitation of the weather and having to work at night. Not being able to [inaudible 01:03:15] objects inside the earths orbit very efficiently. For all those reasons, even in 2005, it was understood that infrared was better. There had been some orbiting infrared telescopes, but at the time the infrared detectors that were being used required to be cooled to very low temperatures with liquid helium. And although it's possible to recycle liquid helium in a space craft, eventually it all leaks away, and the infrared space-based telescopes have not been able to last for more than a couple of years in the cold mode.

Casey Dreier: And just maybe to clarify real quick why we need to cool down infrared is because when things are warm they emit in that wavelengths themselves, right, so they would drown out the detection.

Jay Melosh: That's exactly right. Yeah. That's exactly right. If you were trying to observe an object that is very cold with a warm telescope, it'd be like trying to use an optical telescope that actually glowed more brightly than the object you were trying to see. That's also the problem with doing infrared from the ground, is that the atmosphere blocks infrared radiation. It radiates itself in infrared, and so you can do some infrared work from the ground, and there are a couple of windows at different wavelengths, but the atmosphere itself is warm, and it's radiating away. So you're looking at an asteroid through a haze of in the infrared wavelength glowing light. That makes it very difficult to detect things. Once you get above the atmosphere and don't look toward the earth, objects that we're looking for show up much more brightly.

Jay Melosh: The infrared studies that have been done do pick up asteroids. There was a project called the WISE infrared survey that was originally cooled by liquid helium. The liquid helium has run out. It's still being used, and it's still actually detecting asteroids in the NEOWISE version of the mission. The telescope isn't as cool as it really should be. NEOWISE is doing a great job at the moment, however it's an old spacecraft. The momentum wheels that control it's orientation are failing. One more failure, and it's out of commission so it's not expected actually to last out the year, so we need something new. Missions like NEOWISE, though, have shown us that the proportion of dark asteroids is far higher than we had guessed before. There are a lot of very, very dim objects out there in the optical, but they glow brightly in the infrared. So that's really the way to go.

Jay Melosh: And technology, now, has shown us ways to passively cool an infrared telescope without requiring a lot of liquid helium or other cryogens so that we can actually create a telescope that will last a decade, and not warm up to the point that it's useless.

Casey Dreier: And something else that really struck me reading this report was these advantages you just elucidated about infrared space telescope, they glow brightly in the infrared, and NEOs do. You can look all day right, you don't need to worry about the sun, you can point in all these directions with the space telescope. But the idea that infrared gives you a bonus in a sense level of idea of understanding the characteristics of these near earth objects far better than detecting them with visible light, the light that we see, telescopes. And I'd like to maybe just touch on that a little bit, because that's a really important part that the report went into some really nice detail, mathematically inclined people would find it really interesting. But just in general here, why infrared wise, why is that better in determining the size of near earth objects, rather than seeing them with a regular telescope from the ground?

Jay Melosh: The real hazard of an impact, it comes from the amount of energy that the asteroid brings to the earth. The energy is equal to the mass of the asteroid, times its velocity squared. Now we'll know the velocity of the impact from its orbit, once we know the orbit very well we can predict an impact and we would know the velocity very precisely. But what we don't know is the mass, and that's a major factor in the amount of energy. Now the mass itself is the product of two things. One is the size, and in fact the mass goes like the diameter cubed.

Jay Melosh: Another factor is the density of the asteroid. The optical observations are very ambiguous as to the size, because we don't know the intrinsic brightness of the asteroid. Actually, largely from the infrared observations made by previous missions like NEOWISE, we have an understanding of the relative brightness in optical of a lot of different objects, in fact that's a plot in our report. There are a lot of dark objects in the visible. Also a few bright ones, there's quite a dispersion of the intrinsic brightness indivisible of these asteroids, and if you detect an asteroid optically, you don't know whether it was an intrinsically dark object, therefore very big, or an intrinsically bright object, and therefor quite small.

Casey Dreier: When you say intrinsic brightness, you're talking about just how much of the suns light gets reflected back off the surface, right? So the moon has some intrinsic brightness in terms of the fact that the surface of the moon is reflecting the sun's light, that's what we see at night. And not all the sunlight is going to get reflected, right, that would just be a mirror if that was the case, correct? At 100% brightness, you would just be blinded by looking at something, so.

Jay Melosh: Yes, that's correct. Well it's sort of the difference between say fresh snow, which is very bright and reflects most of the light back, versus something like charcoal that's very, very dark.

Casey Dreier: Right, and so when you first see a near earth object, through a telescope you see this little point in the sky, you have no idea what the surface of that object is like a priori, right? You just see the reflection, but you don't know how much is doing the reflecting.

Jay Melosh: That's correct. You can get a little bit of information if you have enough light from this object that you can get an idea of its color. You can classify different asteroids in terms of their brightness and different colors in the visible spectrum. That helps, because particular types of asteroids, most of them have a given reflectance of light. But actually the darkest objects don't have any very particular color. They're dark at all wavelengths. It helps some. I should back up maybe a little bit and say the optimum situation is to have both the infrared and optical observations.

Jay Melosh: And that brings up the issue that ina addition to detecting the asteroid, once you've detected it, it requites follow up observations, either infrared or ideally optical to get the best information possible on it. One observation of an asteroid isn't enough, doesn't give a very accurate orbit. The best orbits come from observing the object in different locations over time. But once an object is detected, either infrared or visible, a call goes out to other observatories to observe it later and once you've got a number of positions, ideally spaced out as far as possible in time, that will allow the orbit to be determined more accurately.

Casey Dreier: Right. So that's refining the orbit, whether it's going to hit us or not, and also the velocity. But just to complete this though on the infrared, on the advantage of this diameter, we had left it I think at the fact that since we don't know how reflective these surfaces are of asteroids when you first find them, the characteristics of the emissivity, right, the fact that these asteroids glow and radiate off the heat from the sun, that is a much more constrained problem to understand that. Is that correct that in the fact that when you detect that information, the amount of potential error in interpreting the diameter of these near earth objects is much smaller using infrared information than using visible light?

Jay Melosh: Exactly. The emissivity, I've been trying to avoid technical words,

Casey Dreier: I'll let you blame me for that one, but

Jay Melosh: Well, I mean the reflectivity of asteroids for those in the audience who may know it is called albedo, but I've been trying to avoid using that word as being a little bit jargonish. Yeah the amount of infrared light emitted by a surface depends very, very little on what kind of asteroid it is. We generally assume the infrared is emitted with essentially perfect efficiency from the surface, and that has turned out to be a good approximation for virtually very object we've looked at. So that there's a lot less uncertainty when we see the flux of infrared light, a lot less uncertainty in the size.

Casey Dreier: And the report goes into greater lengths, but just to go back to that recommendation, I think we've established here that there are significant advantages to looking for near earth objects in infrared for constraining the potential size, and thus the potential impact energy. And also just for finding them, you can find them faster. If NASA is going to take this congressional mandate seriously, the fastest way to find these near earth objects is to build and launch and operate a space based infrared telescope.

Casey Dreier: Going to the next recommendation, then, you had I thought was really interesting, and I think is going to have some long lasting policy implications that we're starting to see. Your committee recommended that missions meeting these planetary defense objectives, the sense of defending earth in some way from these objects, should not be required to compete against missions meeting high quality, or high priority science objectives. So basically saying that these missions shouldn't compete with science missions in a sense. Explain to me some of the thinking there, and why was that a recommendation? How has this been a problem in the past, and why shouldn't they compete with science missions? Isn't that what NASA should be doing?

Jay Melosh: Well, yes. But well the history is that several of these asteroid finding missions have been proposed in the past, but they were put up against pure science missions and not funded because they did not have the science return that their competitors might have had. And so that recommendation comes out of the experience of a number of members of the panel who do infrared astronomy. In terms of science versus non science, it's clear that this program will produce things of great scientific interest. At the same time, the observing campaign is driven by scientific understanding, for example the fact that there are a lot of dark asteroids out there, which is an interesting scientific understanding.

Jay Melosh: The asteroid finding purpose is not strictly science. If you were doing science you might want to survey not just earth crossing asteroids, but all asteroids. What we propose is not optimized for finding all asteroids in the solar system, for example. It's optimized for finding those that cross the earths orbit, and are therefor a hazard. In the past, missions like this have not risen to the level that they were able to compete with missions that had a purely scientific goal.

Jay Melosh: None of us on the committee has any doubt that there will be a lot of good science that comes out of this, science that we can't anticipate. But the major goal in addition to science, it's also human welfare.

Casey Dreier: Basically saying, if you want to do a planetary defense mission, don't make it compete for these other set of objectives to get selected for funding. Make it a planetary defense contingent selection [crosstalk 01:16:17] it seems unfair to just slot in two responsibilities, you have to be a great planetary defense mission, and you have to do better science than any other potential science mission out there.

Jay Melosh: Yeah, well missions like this have not succeeded before, so but if we [crosstalk 01:16:33]

Casey Dreier: That's a high bar, obviously.

Jay Melosh: If we want to do planetary defense, if we want to satisfy the Brown amendment, insofar as we can, I mean we can't meet 2020, but we can probably meet the requirement within 10 years. In order to keep people safe, we need to use criteria that are beyond that just of science, and that's what that recommendation is for.

Casey Dreier: Again, I just find that really fascinating too, because part of that Brown amendment, in addition to creating the mandate for finding these near earth objects, it actually altered and changed the 1958 NASA act that created NASA, and it added a subsection of congressional expectations and priorities for what NASA should do, and finding NEOs is now part of NASA's official mission. So even though that was passed back in 2005, this report was fascinating to me because it finally just kind of stated as an official recommendation from the national academies, that if you want to do planetary defense as NASA is now directed to do, don't slot it into some other part of NASA. Make it a specific aspect of NASA's internal structure to support those types of missions.

Jay Melosh: That's correct. NASA wasn't doing it itself, so we felt that we needed to recommend that NASA do what its own charter says to do.

Casey Dreier: Which again, this is what I love about seeing how this process comes together. It sometimes takes just an official report, or really, I mean if you think about it, it took a group of respected people like yourself and your colleagues, and the staff at the National Research Council to sit down and effectively just write that down. To think through it, write it down, have it be reviewed by others, and the action of you just sitting, thinking, and writing creates these long lasting consequences, because it's not like you have an enforcement authority. There's not jackbooted police officers at the National Academies that will storm and make them add a planetary defense line. It's purely by the respect that the larger community has for you that just writing this down can create long lasting change. And then ultimately, hopefully, create these missions that are going to protect us indefinitely in the future from these types of asteroids.

Jay Melosh: Yeah well we don't, certainly I don't have insight into how NASA does its internal decision making nor did anybody on the panel, but we were doing our best to try to push the system toward being able to fulfill this requirement.

Casey Dreier: And it seemed to work, right? Because not long after your report was released, and to emphasize again, your job ended with this report. The committee disbanded and that was that, effectively, correct?

Jay Melosh: To some extent. One of the things that my job as chairman entailed, which by the way I didn't know before I accepted the job, was to testify to congress, which frightened me a little bit but I was assured that I would have the Academy lawyers with me. That actually hasn't happened yet. I did do a presentation to Office of Management and Budget, which was not terribly supportive of this. Anything I'm told that involves spending more money is something they avoid. [crosstalk 01:20:05] Or try to avoid, that's their job.

Casey Dreier: That's their job is not to be excited about that.

Jay Melosh: And then I also gave a presentation to the NASA upper administration, and I wouldn't say that I felt that reception was very positive. There were a lot of critical questions, and I came away from that thinking NASA's not going to do this. They are not very excited about it. And there was a little publicity right after that that was also rather negative about the reception of the report. So when a couple months later I heard that it was decided that NASA would in fact be funding such a mission, I was really quite astonished, so obviously something is going on inside NASA decision making that I don't have insight to, but I'm very pleased that that happened.

Casey Dreier: Yeah, and I think it's one of those when everyone can point to a common respected source, that just helps the whole process I feel like work through this, that there's this consensus almost opinion that this is indeed valuable effort, and not just the representation or goal of a special interest, or subgroup within the community. It really changes the aspects of this, and of course to emphasize it, the point that we're recording this, so far all that we've had is a broad statement of intent to pursue a mission of space-based infrared looking for NEOs. We have yet to see exactly how much money is going to be requested, much less how congress is going to fund it. So we're still at the early stages of this.

Casey Dreier: What I feel has changed is that this report somehow, and again I share I don't know the internal machinations either, but this report clearly influenced that internal deliberation to create a base of support for finally changing, and it's not just the mission but they've changed the structure to say we're going to have an ongoing spacecraft flight line that is going to pursue planetary defense focused missions that are separate from science missions, exactly as you recommended. And that fundamental change will help these types of missions, not just NEOcam, but all future kind of planetary defense missions move forward, because now NASA will start to internalize and build into its bureaucracy, this expectation that one of its jobs, it's just aeronautics, it's not just science, it's not just human space flight, now it's also planetary defense.

Jay Melosh: I hope that is in fact the outcome. NASA doesn't just do science, in fact, most of its budget is associated with human space flight, which contributes to science, but itself like this proposal is not directly science based, so I think it's entirely appropriate that this should be a part of the NASA mission, and glad that your feeling is that we contributed to that.

Casey Dreier: Again I really recommend that listeners check out this report, we'll link to it in our show notes. You can read the executive summary, I recommend reading the whole thing. You'll get masterclass in the importance of finding near earth objects, why they're important, why infrared works better than the visual length. It's a fascinating read, and so Dr. Melosh, I just wanted to congratulate you and your team on putting this report together, and again just the process of doing this, the contributions you make to the field, and your colleagues make in this role, you just see how the process of policy, how does NASA choose to prioritize missions over another, why dot hey move forward with planetary defense or not, comes down to a lot of this... I would say unglamorous is a correct way to... the fact that these types of hard work that you and your colleagues do to create the baseline expectation and consensus to build these forward in terms of policy perspective.

Casey Dreier: So anyway, it's fascinating for me to see this process move forward, anda gain the role that scientists play in this it's not something you get a lot of either money or fame for right, it's just a lot of extra work that you do in addition to your day job, so really the whole system depends on people participating, and respecting that process.

Jay Melosh: Yes I think that's a good summary and I should emphasize again that the participation in the panel is entirely voluntary. None of us are paid, it's one of the things we do as part of our professional responsibilities to try to keep things going. When this thing is finally built and flies, it won't be just our contribution, like any spacecraft mission, thousands and maybe tens of thousands of people will be playing critical roles. The people that build the spacecraft, the people that launch the spacecraft, the machinist that assemble the instruments, all that sort of stuff requires the input of a large number of people who are dedicated to making technology go forward, and in this case keeping humanity safe.

Casey Dreier: It's a good note to end this on. Dr. Melosh, I want to thank you again for joining us at the space policy edition, and I hope to have you back in future episode.

Jay Melosh: Thank you.

Mat Kaplan: Casey Dreier, the chief advocate of the Planetary Society in a deep conversation with Jay Melosh, professor from Purdue University and the chair of that national academy of sciences program that reached the conclusion that helped to lead toward NASA's decision that we need a space-based infrared telescope to help save humanity and now Casey, so is NASA about to announce the formation of a saving humanity directorate?

Casey Dreier: Well, that's kind of the alternate name for the Planetary Defense Coordination Office, but that was stood up in 2016. So they're a little ahead of the curve on that one.

Mat Kaplan: Yep. And of course we will continue to talk to those folks, including the Planetary Defense Officer, been a fascinating guest on this show several times. Really fascinating look behind the scenes there Casey.

Casey Dreier: Yeah, thank you. That was really nice of Dr. Melosh to walk us through that kind of process, and I encourage people to read that report. It's online, you can find it. We'll link to it in the show notes, you can jus tread the executive summary if you want, but the entire thing is really... it's written for non experts. If you really want to understand the mathematics of why we need IR space telescope, if you want to understand the statistical understanding of near earth objects, even the basic history of why we're here at this point, it's a great read.

Casey Dreier: And that's the value of these reports is it written for people across the world who are curious, and interested, but not experts. And that's really the value of these reports. They're really, literally written for people like you and they're very fascinating to dive into. You will become, I guarantee you, probably one of the top 1% experts in this field just by reading a report like this and internalizing its key items

Mat Kaplan: Well that and listening to the Space Policy Edition and Planetary Radio on a weekly basis as well

Casey Dreier: That goes without saying

Mat Kaplan: We'll do that for you. Well put up a link to that report from jay's group brought together by the NAS, on this SPE space policy edition episode page at, and I will mention the NAS, the National Academies, they write reports on all kinds of stuff. It's an amazing diversity of topics that they are asked to look into and these are all available, every week I get email from the academies that have links to the most recent work that they have underway. It's really fascinating, and it is there for everybody as a public resource. Really a great service. With that Casey, I guess we'll say goodbye except that we will leave people once again, with a pitch to join us, to join the work that makes it possible for us to bring you the Space Policy Edition. Best way to do that is become a member of the Planetary Society.

Mat Kaplan: Join us at, or at least go there and find out what our members are up to. What they enable us to do with the support that they provide, because we depend on it. It is how we are able to do all the work that we do, including the work that is conducted by Casey and his associate Brendan Curry in Washington DC. The advocacy efforts by the Planetary Society that have been, and with your support will continue to be so effective. And you can join us in this advocacy effort. Don't forget the day of action. One more pitch for that Casey?

Casey Dreier: Yeah, I mean again, if you want to do more than just be a space fan, if you really want to be a space advocate come join me and other staff from the Planetary Society of the members in Washington DC this February 9th and 10th. That's, I really hope to see you there, it will be worth your while. And who knows, it'll be perhaps a very exciting time in Washington DC to be there while you're there as well. So go where the action is.

Mat Kaplan: Hopefully not too exciting, but I'm sure it's going to be fun. And I look forward, I hope, to seeing you there Casey, and I look forward to talking to you again on the first Friday in December, when we will once again do the space policy edition, and encourage all of you to join us then, and hopefully to tune into the weekly edition of planetary radio where we'll have another episode for you every Wednesday morning. Thanks, Casey!

Casey Dreier: All right, Mat, it's always a pleasure.

Mat Kaplan: Absolutely. Casey Dreier, he's the chief advocate for the Planetary Society. I am the host for Planetary Radio, Mat Kaplan, and we'll see you around the cosmos. Ad astra, everybody.

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