Planetary Radio • Jul 01, 2020

Jim Bell Sends New Eyes to Mars

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Jim Bell

Past President (2008-2020), Board of Directors of The Planetary Society; Professor, School of Earth and Space Exploration, Arizona State University; Principal Investigator, NASA Perseverance rover Mastcam-Z instruments

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Bruce Betts

Chief Scientist / LightSail Program Manager for The Planetary Society

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Mat Kaplan

Senior Communications Adviser and former Host of Planetary Radio for The Planetary Society

Mastcam-Z is the main camera system that will soon leave for Mars as part of the Perseverance rover. Mastcam-Z Principal Investigator Jim Bell is back to tell us about what the most powerful set of eyes to reach the surface of the Red Planet may show us. Planetary Society Solar System Specialist Emily Lakdawalla explores four sample return missions headed out across our solar system. The Antikythera Mechanism, an ancient Greek computing device, anchors this week’s What’s Up segment with Bruce Betts. And someone will win one of Jim Bell’s books in the new space trivia contest.

Mastcam-Z stereo testbed team picture
Mastcam-Z stereo testbed team picture On February 6, 2018, the Mastcam-Z team captured their traditional team photo in an unusual way: with the stereo testbed model of the camera. These twelve pictures are left- and right-eye pairs of images that can be used to make up two three-image stereo mosaics of the team.Image: ASU
Megan Barrington and Mastcam-Z in the Malin Space Science Systems Clean Room
Megan Barrington and Mastcam-Z in the Malin Space Science Systems Clean Room Megan Barrington, a Mastcam-Z graduate student collaborator from Cornell, sitting in the cleanroom, looks on as the two “eyes” of Mastcam-Z take hundreds of test images.Image: Jason Van Beek/MSSS

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Focus on Mastcam-Z This animation consists of images taken by the left Mastcam-Z flight camera during one of the 100 dot target tests. After each test, the target was moved to a different distance from the cameras. Mastcam-Z was swept through its full zoom range. By imaging this target at so many positions and distances while varying focus and zoom, the Mastcam-Z team will precisely understand the geometric distortion introduced by the Mastcam-Z optics into its images and measure the effective focal length and field of view at each focus and zoom position. MSSS Operations Engineer Jason Van Beek (left) and Cornell Mastcam-Z graduate student collaborator Paul Corlies (right) were the cleanroom technicians for this testing.Video: ASU/MSSS

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Trivia Contest

This week's prizes:

Take your choice of Jim Bell’s two newest books, Hubble Legacy: 30 Years of Discoveries and Images, or The Earth Book: From the Beginning to the End of our Planet.

This week's question:

What do the following have in common? The Venus atmosphere near the surface of the planet, and some coffee decaffeination processes.

To submit your answer:

Complete the contest entry form at or write to us at [email protected] no later than Wednesday, July 8th at 8am Pacific Time. Be sure to include your name and mailing address.

Last week's question:

Create and share your LightSail joke! Mat and Bruce will judge submissions based on their entirely subjective and often juvenile senses of humor. Special extended deadline is 8 July 2020, so no excuses!


The winner will be revealed next week.

Question from the June 17 space trivia contest:

An ancient Greek analog computer used to predict planetary motions was retrieved from the sea in 1901. It dates from somewhere between 87 BCE and 205 BCE. What was this relic called?


This ancient Greek analog computer is called the Antikythera Mechanism.


Mat Kaplan: Jim Bell sends new eyes to Mars, this week on Planetary Radio. Welcome. I'm Mat Kaplan of the Planetary Society with more of the human adventure across our solar system and beyond.

Mat Kaplan: The principal investigator for Mastcam-Z, the twin zoom cameras that will reveal the Red Planet as never before, joins us as the launch of the Perseverance Mars rover approaches. Jim will also tell us about his latest books.

Mat Kaplan: Emily Lakdawalla returns with a review of the four brave sample return missions underway or launching this year. It's ancient Greek computers and a new look at the night sky for Bruce Betts in What's Up and someone will win one of Jim Bell's great books.

Mat Kaplan: Here's a sampling of headlines from this week's edition of The Downlink, the Planetary Society's newsletter, NASA's Perseverance rover is all buttoned up inside the nose cone, the Atlas V rocket that will blast it toward Mars in a few weeks. Launch is scheduled for no sooner than July 22nd. We have a comprehensive, continually updated guide to all three Mars missions that are about to begin. You'll find it at

Mat Kaplan: NASA Administrator Jim Bridenstine announced last Wednesday that the agency's headquarters building in Washington, DC will be named after Mary W. Jackson, the first African American female engineer at NASA. The building sits on Hidden Figures Way.

Mat Kaplan: Bob and Doug's excellent adventure on the International Space Station continues. Yeah, I know I'm mixing entertainment metaphors. Bob Behnken and the Expedition 63 Commander Chris Cassidy have completed a spacewalk that had them replacing aging batteries.

Mat Kaplan: And here's the story we'll have to follow, a group of scientists at Harvard and other universities has received NASA's first ever funding to search for signs of intelligent life on exoplanets. These so-called technosignatures might include evidence of industrial pollutants in a distant world's atmosphere, which would seem to put a limit on how much smarter than us they may be. You'll find more at and you can find my own monthly newsletter at They're both free.

Mat Kaplan: Here is the Planetary Society's Solar System specialist, Emily Lakdawalla. Emily, welcome back. Let's talk about this brand new piece about sample return. You call that Sample Return Roundup. It's in the new June Solstice issue of the Planetary Report, the free magazine from the Planetary Society, which is available right now at

Mat Kaplan: Jim Bell will shortly mention the sample return goals and Perseverance on our show. We'll talk a little bit about those. But you mentioned that it is a banner year for other sample return missions as well. What are we looking forward to?

Emily Lakdawalla: Well, it's kind of an interesting year. There are actually four missions that are going to be active this year that are in some way involved in sample return.

Emily Lakdawalla: Perseverance is actually the one that's going to take the longest for samples to get back. There's two missions active right now gathering samples or have already gathered samples, and one that's going to be launching later this year.

Emily Lakdawalla: So, the two active ones are both at near-Earth asteroids. They are Japan's Hayabusa-2 and United States OSIRIS REx mission, which will both bring back samples of near-Earth asteroids.

Emily Lakdawalla: And then later this year, China is going to be launching Chang'e-5, which will be kind of the culmination of their lunar plans. They will have a lander on the surface of the moon and a rover that will gather samples and return them to Earth, which will be a first since the end of the Apollo and Luna missions. So, it's really a big year for sample return.

Mat Kaplan: Let me ask you about that mission and we have hundreds of kilograms of moon rocks. Why do we need more?

Emily Lakdawalla: Well, of course, it depends on who you ask. Any lunar scientist would be affronted by the idea that there's ever any such thing as enough, so I need to speak for them first. But no, it's a legitimate question.

Emily Lakdawalla: It has to do with what we learned actually from the Apollo and Luna missions. Apollo was very limited in their choice of landing sites. They had to land within a fairly narrow region on the near side of the moon so that there could be communication with Earth and near the equator because that's what trajectories required in order to get astronauts and the very heavy spacecraft to the moon down to the surface and back.

Emily Lakdawalla: And we found out later that nearly all of the sites that the Apollo astronauts sampled, even though they seem to be diverse when we first sampled them, were all contaminated by a single gigantic impact, the Imbrium impact.

Emily Lakdawalla: And so, we can't be entirely certain that we really have sampled the diversity of lunar rocks. In fact, we definitely haven't sampled younger rocks than the Imbrium impact. And that's the main goal of Chang'e-5 is to sample some of the very youngest volcanic rocks that the moon produced, and it's going to be very interesting to see the results from analysis of those samples.

Mat Kaplan: I knew there had to be a great answer for that question. Remind us once again, though our audience has heard this a few times, why sample return is still so important. Why do we need to get this stuff back to terra firma?

Emily Lakdawalla: There are a couple of reasons why it's so useful. First of all, the sample analysis capability that a spacecraft can carry to the surface of another planet is extremely limited compared to what we can do in laboratories on Earth.

Emily Lakdawalla: On Earth, we can take samples, fairly small amounts of sample and divide them up among hundreds of laboratories. You can do things like repeat the same analysis in different labs to make sure that the results are in fact repeatable, which is very important aspect of the scientific method. You can also apply analysis techniques that require enormous laboratories, things that couldn't possibly be miniaturized.

Emily Lakdawalla: One of the things that's very important to do with samples is to figure out how old they are and how old are the events that happened to the samples that may have reset some of their age mechanisms. If you can do that with samples brought back on Earth, the number of different kinds of analyses that you can do are just multiplied.

Emily Lakdawalla: And then one really cool thing you can do with samples is that you can save them. You can save them until new analysis techniques are developed, which is why the Apollo samples have continued to produce new scientific results year after year after year because we keep developing new ways to analyze them. They're the gift that keeps on giving. Once we get these samples back to Earth, we'll be learning new things from them for many decades to come.

Mat Kaplan: Yeah, I remember standing in that lab at the Johnson Space Center looking at the moon rocks that have not and would not be touched for perhaps years into the future, waiting for those new techniques.

Mat Kaplan: Let's finish by returning to Perseverance and its goals on Mars, at least the process that it hopes to begin. Do you get the feeling that after decades of talking about this, it may happen this time?

Emily Lakdawalla: Well, I feel a couple different ways about that. I think that we are definitely much closer to sample return than we have ever been before.

Emily Lakdawalla: If you see the process towards sample return as a bunch of necessary steps that need to be taken, we've taken steps that have never been taken before. We have developed a mission that is going to collect samples for future return. And NASA and ISA have started the process of developing a cooperative set of missions to go to Mars and retrieve them. There's still a lot that we have to do. But it is encouraging that we've taken these steps that haven't been taken before.

Emily Lakdawalla: It's going to take a lot of money. And it's going to take long-term commitment that spans more than one presidential administration. And recent American history has shown that it's been tough to do that in space. Things tend to blow back and forth with each election. It remains to be seen if we can stick with this plan, but it's at least going in the right direction.

Mat Kaplan: And listeners and members of the Planetary can bet that the society will continue to pursue that commitment, making sure that it is something that is not as our old boss, Lou Friedman, used to say always 20 years in the future, maybe just 10 or 11 years now. Emily, thanks very much. Great job as usual.

Emily Lakdawalla: You're very welcome, Mat.

Mat Kaplan: That's Emily Lakdawalla, the solar system specialist for the Planetary Society, our planetary evangelist.

Mat Kaplan: When Perseverance, the former Mars 2020 Rover, arrives on the Red Planet next February, it will raise its mast and begin to share the best images ever taken of the Martian surface, stereo images and sometimes movies.

Mat Kaplan: Mastcam-Z with a Z standing for zoom is the product of years of work by an international team led by Jim Bell. Jim is professor of geology and planetary science in the School of Earth and Space Exploration at Arizona State University. He has been part of many, many missions of exploration and he is also a first rank communicator about the passion, beauty and joy he has found in this work.

Mat Kaplan: His best-selling Postcards from Mars has been followed by many other books. I'll talk with him about the two most recent ones toward the end of the great conversation you're about to hear.

Mat Kaplan: Full disclosure, Jim is also president of the Planetary Society. Jim Bell welcome back to Planetary Radio. It's great to be talking to you again.

Jim Bell: Mat, I love Planetary Radio. It is spectacular to be on the show. Thank you so much.

Mat Kaplan: That's very kind. Thank you, sir, especially coming from the president. I hope that the science guy and my other bosses are listening.

Mat Kaplan: Listen, many of our listeners know that I was in the High Bay at the Jet Propulsion Lab a few months ago, and I was staring in wonder at Perseverance, formerly known as the Mars 2020 Rover.

Mat Kaplan: As I did that, it looked like two eyes were staring back at me. I was so proud not just because the society is an education and outreach partner for Mastcam-Z but that's a big part of it. I mean, you, if I felt proud, you must have felt at least 10 times that level of pride.

Jim Bell: Absolutely, of course, and I am incredibly proud of the team that includes the Planetary Society for education and outreach, but a team of dozens and dozens of people at Arizona State at Malin Space Science Systems, at JPL, at vendors and contractors across the country, who have helped to put these amazing new robotic eyes together and of course, all of the other systems and instruments and capabilities that Perseverance is going to bring to Jezero Crater, spectacular.

Mat Kaplan: I may come back to that team that you've assembled to build and hopefully very soon to operate this instrument on Mars. You said it, Perseverance is covered with eyes but yours are up top, and by far the best. A lot of the audience has heard this before. But could you give us a quick sort of repeat overview of Mastcam-Z?

Jim Bell: Sure. Mastcam-Z is a camera system for Perseverance up on the mast about two meters above the surface. That's a pair of essentially identical cameras left and right eyes to give us stereo 3D views.

Jim Bell: Many listeners know that the Perseverance itself is made from something like 90% spare parts from Curiosity, which is how NASA was able to fit this new mission into the budget. So, we knew that we had to fit a camera system on essentially the same mast as Curiosity. Curiosity carries a camera system called Mastcam, which is the left and right eye, one is wide angle, the left eye and one is telephoto, the right eye. So, great images and you've all seen the images from Curiosity, but it's a bit myopic, right? Because you got a wide angle view on the left and a telephoto view on the right. And it makes doing stereo difficult, not impossible, difficult. You can only do it at the resolution of the low resolution camera.

Jim Bell: Our idea was to build on that heritage and give Mastcam zoom capability, which is the Z that Mastcam-Z means that it's a zoomable mast camera. And so, we were able to build a four to one zoom lens system into that designed to fit it into the same space.

Jim Bell: So, this is in a lens about the size of a can of tennis balls, for example. Therefore, we could match the focal length, the zoom of both the left and right eye and get lots and lots of stereo, including at the highest resolution, which is about 110 millimeters focal length. We're going to build upon that heritage of imaging from Curiosity and expand upon it with a lot more stereo and high resolution.

Mat Kaplan: If I read the specs correctly, my smartphone apparently has far more pixels than Mastcam-Z. And if that's the case, how is it that this is still the best camera ever to be sent to the surface of Mars?

Jim Bell: Yeah. No, it's true. Probably a lot of smartphones had better cameras than the ones on NASA spacecraft across the solar system. But it's also true that your smartphone will almost certainly not survive a crazy rocket launch and the shocks and vibrations of a landing system on Mars, et cetera, right?

Jim Bell: So, NASA technology for proven spaceflight capability like this, these technologies typically lag consumer technology, because that stuff just has to be so ruggedized not only to handle the shocks and the vibes and rocket launches and landings, but the crazy vacuum conditions of space, the huge temperature swings on Mars from minus 100, 110 degrees C at night, up to plus 5, plus 10 in the daytime every day, day after day. These are harsh environments that we send these cameras and other equipment out into.

Jim Bell: NASA is, of course, a conservative space agency. Almost all space agencies are conservative. So, their basic philosophy is if it hasn't flown in space and demonstrated itself in space, you can't fly it in space, which is kind of crazy. It would mean you'd never fly anything. So, instead, what it really means is we make incremental advancements in the technology and demonstrate that this new sensor, that this new system can survive in that environment, maybe through a tech demo mission or an orbital mission for example and then it's ready to deep space. So, that causes a 5, 10 years or more lag between consumer technology than typically what NASA is able to fly.

Jim Bell: Now that said, there are HD sensors that are a couple of megapixels. You've seen examples of images from these kinds of sensors in the past and they do a great job.

Mat Kaplan: Catch 22 goes to deep space, and I only wish that my smartphone had a four to one optical zoom. I mean, that would be so cool. Is the entire camera system up there in the mast or are there electronics elsewhere in Perseverance?

Jim Bell: Yeah, there's two ancillary parts of the camera system. The cameras are up on the mast. There's a cable that runs down the mast into the body of the camera where the main electronics are. The electronics drive the camera, send the commands to the camera, get the data back and forth to the camera, store the data, do some image processing like compression and other things. And the electronics box, which sits inside the warm body of the rover, nice and happy at no colder than about minus 30, minus 40 C. That electronics box talks to the rover computer directly. So, it's our interface. So, that's one extra component. It's called the Digital Electronics Assembly, DEA.

Jim Bell: And then the second component is of course our calibration targets, which are sitting up on the deck of the rover, two of them this time. We have a primary and a secondary. And the primary looks a lot like the previous Mars sundials that you've seen on Spirit, Opportunity and Curiosity. It's changed in design a little bit but basically the same. It's a square part with grayscale and color calibration materials on it and a post to cast a shadow.

Jim Bell: And then we have a little L bracket secondary calibration target right near it that has some vertical and horizontal surfaces with color patches to help us compensate for dust collecting on the target. So, we think that vertical surface won't collect a lot of dust and the horizontal surface will. So, we'll see that differential.

Jim Bell: And of course, we still think of that primary calibration target with its shadow post, gnomon as a sundial, our friend Bill Nye, of course thinks of it as a sundial, and it is a sundial. And we will have some education and outreach activities that will build around taking pictures of and using that calibration target on Perseverance.

Mat Kaplan: You have reminded me of my colleague, Mark Hilverda, and how very proud he is. He does a lot of great work for us on our website and more. He got to contribute to that calibration target.

Jim Bell: He did, he did. Just like we have done with previous calibration targets, we have sort of a story in some pictographs and symbols and a sort of a secret message in tiny, tiny font around the edges of the calibration target that we can't read with the cameras, that will only be read by astronauts and tourists who visit Mars in the future.

Jim Bell: And Mark helped do some of the art for that and we're putting an article together right now that describes the story. We're planning to put that out as a Planetary Society blog sometime this summer. So, a lot more about it.

Mat Kaplan: Something else to watch for at, where there is also a page that goes into a pretty detailed description of Mastcam-Z and a record of all of our previous coverage, including the time that I visited with your team there at Arizona State University.

Mat Kaplan: Much more from Mastcam-Z, the principal investigator Jim Bell is coming your way right after a short break.

Bill Nye: Greetings. Bill Nye here, CEO of the Planetary Society. Even with everything going on in our world right now, I know that a positive future is ahead of us. Space exploration is an inherently optimistic enterprise. An active space program raises expectations and fosters collective hope.

Bill Nye: As part of the Planetary Society team, you can help kickstart the most exciting time for US space exploration since the moon landings. With the upcoming election only months away, our time to act is now. You can make a gift to support our work. Visit Your financial contribution will help us tell the next administration and every member of Congress how the US Space Program benefits their constituents and the world.

Bill Nye: Then you can sign the petitions to President Trump and presumptive nominee Biden and let them know that you vote for space exploration. Go to today. Thank you. Let's change the world.

Mat Kaplan: Speaking of those electronics that are deep inside Perseverance, as well as the camera head up on the mast, what does it take to integrate a system like Mastcam-Z with a machine as complex as a Mars rover?

Jim Bell: Yeah. It takes a detailed plan and a lot of patient, steady-handed people. We had the advantage of knowing ahead of time what kind of a mast that we had to put these cameras on because it's the flight spare from Curiosity, so we knew in advance what the volume and the mass and the power and all that kind of stuff is going to be. Lots of times, we don't. Lots of times, the spacecraft folks that are optimizing and tweaking their design while the instrument people are doing the same thing, and then you have this collegial confrontation at the interface that's called integration. And I certainly have experienced that in a number of projects previously.

Jim Bell: But in this case, we knew ahead of time how it had to be built, where it was going to go, where it needed to be fit down to the bolt pattern. So, that was a really good thing. And then it's a bit of a wistful mixed emotions kind of thing because we spent two and a half years designing it and going through design reviews, and the cameras only existed as PowerPoint slides and Excel spreadsheets. And then you start building it once you past your critical design review. We started building it, it took a couple of years to build.

Jim Bell: And test, of course, we did a bunch of the testing on our team at ASU, at Malin Space Science Systems in San Diego with their technical staff, and our engineering colleagues there and at JPL.

Jim Bell: You do all that and we spent a good part of five years with these cameras as our own and then you hand them over, literally, hand them over to colleagues at the Jet Propulsion Laboratory. And it's a little bit of a little trumpets in the background with delivery ceremony kind of thing.

Jim Bell: And then they go off and we never get to really be near them again or work directly with them again. It's almost like your kid going off to college. It's a real milestone in the life of these things.

Jim Bell: And it's a mixed emotions feeling because we know we're never going to get to do as much in detail as close as we've been with them. When you hand them over, they become part of something bigger and something that is incredibly precious and something that people are paranoid about in terms of its safety. And it's part of the bigger system. So, that's what happens when you integrate any instrument into a spacecraft.

Mat Kaplan: So, when did you and your team last touch the cameras? When was that handoff?

Jim Bell: So, that was back in May of last year, so a little over a year ago.

Mat Kaplan: Wow.

Jim Bell: We completed the calibration activities. The camera is on their own now, on the optical tables on a bench in the lab in a small thermal vacuum chamber, either at an ASU or at Malin Space Science Systems.

Jim Bell: We did all the tests we needed to do. We collected all the calibration data that we needed to collect. [inaudible 00:23:11] they performed as we expected, which is great. And they performed great and the image quality is spectacular. And the signal noise is great and all that kind of stuff. And then we handed them over shortly thereafter, about a year ago.

Mat Kaplan: What happens when Perseverance arrives on Mars? How soon will we begin to see those gorgeous images and videos?

Jim Bell: Yeah, the sequence of events will unfold similarly to [inaudible 00:23:43] on Spirit, Opportunity and Curiosity in that on landing day, which is called Sol Zero, we land late in the day on that first Mars day.

Jim Bell: The first images we'll get back will be from the hazard cameras. The wide angle views. The mast is stowed still on the deck of the rover, so we can't take pictures with the nav cams, navigation cameras or the Mastcam-Z's. Those will be the first ones that we see.

Jim Bell: Now, the difference will be that on Perseverance, that hazard avoidance cameras are color this time. They'd been black and white in the past, so we could very well get the first wide angle color images of the landing site, right on landing day as we have in the past. It depends on the quality of the link with the orbiters and all that kind of stuff.

Jim Bell: But those would be the first things to come back. And then there'll be more of those on Sol One. But really, the first couple of Sols is just about hey, did everything survive? Okay, let's check out the basic systems, electronics, the heaters, the power supply, all that kind of stuff, and the mast will still be stowed.

Jim Bell: And then it won't be until the second full day on Mars, Sol Two that the mast will be deployed, pop up. It's just a one-time deploy, pops up. And then we'll get our first nav cam images, which will also be in color, and our first Mastcam-Z views. And then starting on Sol Two, and then going beyond that we've got a whole series of calibration measurements and test images. And we're going to test out the zoom and we test out the focus and we test out the filter wheel, all that kind of stuff.

Jim Bell: And so, we'll be getting like all the other instruments and systems the first few weeks really are mostly about testing things out. And we'll try to collect the highest resolution color multispectral panorama that we can as early as possible because of course, all of us who are also scientists will be chomping at the bit trying to figure out, hey, what's going on around us? Where's that delta? Did you land on it or near it? How far do we have to go? Which direction are we going to start heading? Let's start planning, all that kind of stuff.

Jim Bell: And then you mentioned movies and I think that the first movies that will have a chance to take I think will be associated with the helicopter. The Ingenuity helicopter being carried by Perseverance as well. Early in the mission, they will be doing their test flights, three to five test flights. Of course, the whole thing is a tech demo. It's basically just to demonstrate that powered controlled flight can be performed in the Martian atmosphere and feed the information from these test flights forward to potential future drones that could accompany landers, rovers or people to Mars.

Jim Bell: The helicopters carried on the belly of the rover to be gently dropped on to the surface early in the mission. Rover will back away and keep backing away to a safe distance, maybe 50 meters, maybe 100 meters. And then the helicopter will do its test flights. And so, we're planning to take what I hope will be some really cool movies of that helicopter flying on Mars with the Mastcam-Z.

Mat Kaplan: Man, there is so much to look forward to and of course listeners have been with us while have heard us feature the Mars helicopter a couple of times and we'll be back talking about Ingenuity with some of that team before too long.

Mat Kaplan: If this goes anything like other Mars missions, lots and lots of great science is going to be done. But it is the images that will capture the public's imagination. Not surprisingly, it's human nature.

Mat Kaplan: But Mastcam-Z is just one in this suite of very sophisticated instruments headed to Mars on Perseverance. It's another kind of integration. I mean, how do you integrate the work of Mastcam-Z with the research that will be conducted by these other components of the rover?

Jim Bell: Yeah, it's a great question. And it's something that we think a lot about. We have, of course, like you said, the cameras, take great pictures and enable all kinds of interesting geology and atmospheric science, et cetera. But we also have real responsibility to support the operations of the other instruments and the sample collection process.

Jim Bell: Remember, Perseverance outwardly looks like Curiosity. But inside and in its mission, it's fundamentally different. This is the first part of Mars sample return. We're not just drilling into things. We are coring, collecting the cores, putting those cores into these little tubes, setting the tubes down on to the surface for a future mission to bring back to the Earth.

Jim Bell: So, we take very seriously on the camera team, our responsibility to help document in great detail the context of those samples, the environment in which they were collected, the way that they were collected, the neighboring materials and then environment so that we can put a dossier together for every single sample that we've collected, every single sample that's left onto the surface, and make a super strong case along with all the other instrumental data to bring those samples back.

Jim Bell: The arm has to place several instruments down on to the surface for them to make their chemical and mineral measurements or microscopic imaging measurements. To do that, they need a 3D model of the surface and the navigation cameras will do that. They are designed to provide the required adequate resolution. But if we point the Mastcam-Z cameras at that terrain in stereo at high resolution, we'll get a much higher fidelity 3D model.

Jim Bell: So, we're trying to build those things and give them to the operations team, help the other instruments do their job in the best possible way, help document and archive the collection of data about each sample.

Jim Bell: And we can do the same thing with driving since we can provide higher resolution stereo than the nav cameras that would allow the rover drivers to avoid obstacles better, to go farther into the field if we need to do a super long drive.

Jim Bell: So, yeah, lots of science that we're going to do, Mat, but also lots of sort of engineering and sample collection support as well and building that into our plan.

Mat Kaplan: I told you I wanted to come back to your team. And I mentioned that I had that great afternoon with you and the team at ASU with components of Mastcam-Z prototype, sitting on the table in front of us.

Mat Kaplan: And on your ASU webpage, there is this panoramic shot of the team members that without any justification at all, I'm in that shot because you dragged me in. You're in it three times because you kept moving as the camera panned. It's pretty clever. Tell me more about this very accomplished team and how you pulled them together.

Jim Bell: I'm really a big fan of our team. It's a great mix of colleagues who I have known and worked with for 25, 30 years who've been involved in every single Mars rover mission going back to Mars Pathfinder, Sojourner, who just had an enormous amount of experience and then a wealth of expertise to contribute to operating instruments on Mars and doing science on Mars.

Jim Bell: They're part of the team, but also a number of younger people, some who this is their first rodeo to Mars, and they're super excited. They bring all kinds of new perspective and new ideas and things that, oh, gosh, I wish I thought of that 25 years ago, what a great idea that kind of thing. And they're super excited and we feed off of their enthusiasm, not just US participants, but there's a number of colleagues from Europe and Canada, who are involved on our team.

Jim Bell: There are some colleagues who are involved in the European Mars Express, ExoMars missions. So, they're thinking about how to do their rover mission and they're learning from us and we're learning from them.

Jim Bell: Early career people, number of students, graduate students, undergraduates, postdocs, just a wealth of expertise that covers the geology, the operations, the instrumentation and calibration, the atmospheric sciences, the astrobiology kind of goals that we're going after as a broader science team.

Jim Bell: So, I am super excited to work with all of these folks and they're really proud of what they've been able to accomplish so far.

Mat Kaplan: It was a fun group too. It was just a very enjoyable day there.

Jim Bell: We do a lot of laughing. We had a lot of fun. And when we need to get serious, we get serious and do the job.

Mat Kaplan: All right, I'm going to turn away from a Mastcam-Z and Perseverance though, we will return to both before too long, and look at another part of your life. I don't know where you find the time but you continue to churn out books.

Mat Kaplan: When I went on the website, I saw The Earth Book: 250 Milestones in the History of Earth Science, and I bought it, got the Kindle version. It's beautiful. It's basically an illustrated biography of our planet. And so, I can recommend that personally.

Mat Kaplan: But it turns out that I missed your most recent book, which apparently is a tribute to the Hubble Space Telescope, which, I mean, we were talking about just a few weeks ago on this show with somebody who visited it three times, John Grunsfeld.

Jim Bell: Yeah, and John wrote a great foreword for me for that book. And I was super honored that he did that. It's called Hubble Legacy. April was the 30th anniversary of the launch of the Hubble Space Telescope. And I've been a Hubble user myself to observe Mars and other parts of other teams. And I think it's one of the most spectacular machines that we've ever built.

Mat Kaplan: No doubt.

Jim Bell: And it's a time machine. That's what I call it in the book. It takes us back in time. It's the most powerful time machine that we've built yet. And maybe James Webb will be more powerful but hasn't demonstrated itself yet.

Jim Bell: So, we've got Hubble up there still demonstrating its use for us and we don't know how long it's going to live. It can't be serviced by the shuttle anymore. Although there are ideas or other ways to get to the Hubble, but I thought it was appropriate to have a celebration, gather a collection of, in my opinion greatest hits images, which would be different than your opinion or some or John Grunsfeld opinion or somebody else.

Jim Bell: And so, I have a big section on the solar system, right, which is only about 5% of the time on Hubble but an enormous number of the most spectacular images are from our own solar system.

Jim Bell: And, of course, stars and galaxies and nebulae and clusters of galaxies and the distant cosmos, just a really celebration of all that Hubble has taught us and continues to teach us.

Mat Kaplan: Well, I look forward to checking it out. But as I said, I have been able to at least page through The Earth Book: 250 Milestones in the History of Earth Science.

Mat Kaplan: You opened this book with two quotes, our audience is pretty familiar with one. It's the pale blue dot description or a portion of it from our cofounder, Carl Sagan. But the other one was new to me. And I hope you'll talk about it. It's kind of awe inspiring. The top of Mount Everest is marine limestone.

Jim Bell: John McPhee, right? Great, great writer, geology and earth science. Think about that, right? The tallest mountain on the Earth, you go to the top of the tallest mountain on the Earth. What do you find there? You find sediments from the deep ocean. What the heck is going on, right?

Jim Bell: I mean, doesn't that put it in a nutshell about how dynamic our planet is, right? And of course the whole backstory is plate tectonics and the Tibetan plateau and India smashing into Eurasia, raising those mountains. As a geologist, you get this forensic feeling like there's a mystery here. We got to solve this, right? And that's what geologists do.

Jim Bell: Geology is a forensic science. You visit a "crime scene", right? And it's like what happened here? Look at these tortured rocks. Something crazy has gone on here. And you try to put the story together. And the story tells you about just the spectacular planet that we live on and how precious life is on this planet, how precious our planet is, and our environment is, compared to others. And I touch on that in the book as well. Because, of course, when we study Mars and other planets, ultimately, we learn so much about our own world that way. So, lots of different themes in that book about exploration, discovery and the way that we've learned about how Earth fits into our planetary society.

Mat Kaplan: And as you might imagine, humanity because we're pretty recent arrivals in the history of this planet, we only come in toward the end of the book, but there's some really interesting pages about how human civilization, even very early human civilization, have sort of interacted with the planet and in a geophysical sense, really fascinating.

Jim Bell: Yeah, lots of cultural aspects, cultural and historical anthropology aspects to understanding life on Earth and how we have interacted with and learned to understand our planet.

Jim Bell: And as Bill Nye would say, our place in space, right? Where are we? What are we doing here? And you're right, we are recent. We are recent addition to this planet in the history of life on Earth goes far, far back before us.

Mat Kaplan: I got one more roll that I want to bring up before I let you go. I mentioned upfront of course, you are president of the Planetary Society. It's a position you've held for years now.

Mat Kaplan: You know that my colleagues and I of the society were working to respond to a couple of great challenges, the pandemic and systemic racism in the United States. And I just wonder if you have any thoughts about this struggle and how the society, which you have some oversight over, of course, how we're responding?

Jim Bell: Yeah, it is a struggle. And it's one that we should engage in as individuals and as members of forward thinking, positive looking societies like the Planetary Society.

Jim Bell: We work really hard. The staff and the board work really hard to make sure that we are an international organization, that we are representative of the planet. We are the Planetary Society, Earth is a planet. So, we work to get our message out to the world, geographic, diversity, critical to us, cultural, ethnic, gender, sexual orientation. All of this diversity makes us stronger as a species, makes our society stronger.

Jim Bell: I was really moved by the conversation that Bill Nye had with Leland Melvin, astronaut, explorer, philosopher. And you can find that on our website, of course talking about space and his visits to space was the main point. But of course, his perspective, his perspective as a black man, as an astronaut, representing that entire aspect of diversity that we're trying to capture.

Jim Bell: And he's got some amazing stories and they're not just about space exploration, they're personal stories, they're about how so many people have struggled to get the basic rights that we aspire to.

Jim Bell: And so, I was really proud of Bill. And of course, Leland is an amazing guy. And I hope people will check out that conversation.

Jim Bell: We take a planetary perspective. We are one planet, we are one species. And so, making ourselves representative of the world of the species is a real important goal for the Planetary Society.

Mat Kaplan: And as I have said in this context recently a couple of times on the show, that's part of our mission, empowering the world citizens.

Jim Bell: Exactly, exactly. Again, I was very moved by that conversation. And I hope we have more.

Mat Kaplan: Yeah, me too. I'm sure we will. And, Jim, I look forward to more conversations with you. As always, it has been a pleasure and an honor. Where are you going to be on July 22nd or hopefully not long afterward?

Jim Bell: Yeah, of course, we were all planning to have a big team meeting at the Cape and enjoy the launch in person. And that's all been set aside of course, because of COVID.

Jim Bell: But we'll be having some sort of virtual online celebrations with the team at ASU and MMS Kinsey team spread around the world and the Mars 2020 science team, of course will be following the NASA JPL launch feed like everybody else, the countdown and then watching us, our children cameras and other instruments fly off into the sky to their permanent home in Jezero Crater on Mars. It’s going to be very emotional.

Mat Kaplan: And then early 2021 after those seven minutes, seven more minutes of terror.

Jim Bell: Right, right. February 18th, 2021 like midday Pacific Time, I think it's landing.

Mat Kaplan: Can't wait for the snapshots. Thank you, Jim.

Jim Bell: Thanks for having me on, man. I love the show. You're doing a great job. Let's keep working to change the world, man.

Mat Kaplan: You bet. Jim Bell. He's professor of geology and planetary science in the School of Earth and Space Exploration at Arizona State University and as you've heard, he's principal investigator for Mastcam-Z on Perseverance, NASA's next Mars rover that will leave for the Red Planet on or soon after July 22nd.

Mat Kaplan: He's also a best-selling author of, well, Postcards from Mars was one but his latest books you've just heard about, Hubble Legacy: 30 years of Discoveries and Images, which I haven't seen yet, and The Earth Book: From the Beginning to the End of Our Planet, 250 Milestones in the History of Earth Science. And he's the president of the Planetary Society.

Mat Kaplan: I've also often called him the Ansel Adams of Mars. You'll get another chance to display that before too long. And you should stick around for a chance to win one of Jim's books, one of the ones we just talked about, in What's Up with Bruce Betts, which is coming up in moments.

Mat Kaplan: It is time for What's Up on Planetary Radio. This is the chief scientist of the Planetary Society. It's Bruce Betts and he is here to tell us all about the night sky. He of course also is the program manager for LightSail. And if you haven't seen the video, the on-demand video of the live celebration we did last week at the one year mark when LightSail went from primary mission to extended mission, you should. It's at Okay, welcome. That's all the time we have, Bruce.

Bruce Betts: Okay. Thanks, man. Everybody go out there, look up the night sky and think about what it would have been like to listen to What's Up episode. Thank you and good night.

Mat Kaplan: Hey, happy post asteroid day as well.

Bruce Betts: I don't know what the appropriate greeting is for that. But sure, happy post asteroid day, commemorating the 1908 Tunguska impact and reminding us that the asteroid threat is real, but something we can do something about. You can learn more at We've got all sorts of asteroid information.

Mat Kaplan: I think the proper response to happy asteroid day is, whew, another one missed us.

Bruce Betts: Maybe it is. Maybe it is.

Mat Kaplan: What's still up there?

Bruce Betts: A lot of asteroids but hopefully you won't be seeing any of those, I mean, unless you're in the telescopes and looking at asteroids, which is good.

Bruce Betts: So, anyway, updating the night sky from our just using your eyes perspective coming up in the late evening 10:00, 11:00 PM, we've got Jupiter really bright and near it, Saturn looking yellowish and on July 4th, the moon will be lining up with them, July 5th that night the moon will be nearly full and between Jupiter and Saturn, kind of a neat view. Couple hours later, bright Mars will be rising the east and will be getting brighter and brighter over the coming weeks and months. It's going to be cool.

Bruce Betts: In the pre-dawn east, we've got Venus now getting easier to see higher up, super bright Aldebaran, the brightest star in Taurus that's about 100 times dimmer than super bright Venus will be below it and passing by it over the next two or three weeks. They will be one degree apart. So, about two full moon widths on the 11th and the 12th of July. The moon will join Aldebaran and Venus for a party on the 16th and 17th. You'd go to that party.

Mat Kaplan: I'm there.

Bruce Betts: All right, we move on to this week in space history. Two big successes for which Planetary Society had major events, 1997 Mars Pathfinder successfully landed on Mars. In 2005, Deep Impact spacecraft successfully bashed a comet with an 800 kilogram ball of copper, making a crater.

Mat Kaplan: I just finished Lou Friedman's new book and he will be on our show to talk about it before too long. It's remarkable how many significant milestones in planetary space exploration the Planetary Society has had a hand in since its formation. His book is a good way to find out about those. So, stay tuned.

Bruce Betts: I will. Moving on to Random Space Fact. Stay tuned for Random Space Fact. On Venus, the atmospheric density at the surface is so dense. How dense is it?

Mat Kaplan: You took my line.

Bruce Betts: I know, right? How dense is ... No.

Mat Kaplan: No.

Bruce Betts: The atmospheric density at the surface of Venus is so dense.

Mat Kaplan: How dense is it?

Bruce Betts: That it's about 6.5% the density of water, six and a half percent the density of water.

Mat Kaplan: Wow.

Bruce Betts: Wait, that was no joke? No, it's real. For comparison, that value for Earth is about one tenth of 1% compared to six and a half percent the density of water on Venus.

Mat Kaplan: That's insane. If you were dumb enough to go there without a very, very good spacesuit, could you swim in that atmosphere?

Bruce Betts: That is a good question. And I would say probably not, but you could if you just did your density enough. So, if you're super good space spacesuit had some balloons with air in them, no, I don't know. You've stumped me again. Stop it, Mat.

Mat Kaplan: I'll stop. But look into that, please. Okay, go on.

Bruce Betts: All right, we'll move on to the trivia contest. I said, an ancient Greek analog computer used to predict planetary motions was retrieved from the sea in 1901, dating between 87 BCE and 205 BCE. What is this relic called? How did we do, Mat?

Mat Kaplan: What a huge response. Apparently, there are a lot of other fans of this ancient computing device out there, this ancient analog computer.

Mat Kaplan: Joining me in my fascination with it, one of you directed me to Amazon, I've said there was a model of it, not exactly that I could find. There were some things you could build. There are t-shirts, which I might have to get one of these. I don't know, Bruce. What was it? What's the correct answer?

Bruce Betts: I have no idea, Mat. I'm glad our listeners do know. It's the, and I apologize if I don't know how to pronounce the Greek, the Antikythera mechanism, the Antikythera mechanism. Can you help me with pronunciation there, Mat?

Mat Kaplan: Well, here's how Dave Fairchild, our poet laureate put it, Antikythera. No, I have to get the emphasis right. Easy for me to say, Antikythera found in the ocean was made by the Greeks a long time ago. It had a lot of gears spinning together and showed many things that astronomers know, lunar eclipses, the solar ecliptic, the zodiac signs, inter-calorie days, which I had to look up. It was as cool in the time it was built as the Apple Watch is to us folks nowadays.

Bruce Betts: Nice and wonderful pronunciation. You did an excellent job.

Mat Kaplan: You think? So, here's our winner, brand new, first time winner in the Netherlands, [Edna Guetta 00:49:06]. I don't think I've done a better job with her name than I did with the Antikythera.

Mat Kaplan: And she gave it to me phonetically. But this is the closest I can come, Edna Guetta. As I said, in the Netherlands, she indeed said it's the Antikythera, I'm just pronouncing it the way most Americans probably would, mechanism.

Mat Kaplan: Congratulations, Edna. We're going to send you the Antikythera. No, we're not. We're not even going to send you a rubber one. But we are going to send you a Planetary Society rubber asteroid.

Bruce Betts: I should look into producing rubber Antikythera mechanisms.

Mat Kaplan: At least out of foam rubber, be hard to make gears that mesh, maybe hard rubber, maybe was. I don't know. I got more. You want to hear more?

Bruce Betts: Oh, I do very much.

Mat Kaplan: From Jake Manning in Illinois. Yay. I get to combine my passions of Bronze Age history and space with this one.

Bruce Betts: Yes.

Mat Kaplan: Bob Clayton in Arizona, our pun master, I guess, who could be auntie kissing any area? I like to be kissed, don't you?

Bruce Betts: Yes.

Mat Kaplan: Another poem. This is quite a work from Jean Lewin in Washington. Between the islands of Peloponnese and Crete, beneath the blue Aegean Sea, sponge divers found an ancient wreck dating from BCE. Within its bones and encrusted piece containing at least 30 bronze gears, a prochronistic analog device, yes, well beyond its years. Its origins could be from Rhodes, though there are skepticism. So, name for the island near where it was found, the Antikythera mechanism.

Bruce Betts: Wow, that's an impressive rhyming.

Mat Kaplan: I know. There is some good work there. Ola Franzen in Sweden, although it looks cool, I must advise that the frame rate when running is terrible and the developers seem to have stopped releasing updates quite some time ago.

Bruce Betts: Darn.

Mat Kaplan: And finally, this one, short but sweet. From [Ian O'Neal 00:51:07] in Japan. Took a licking, stop ticking. Which dates us a little bit. Timex commercials for those of you not in the know. Look it up. It's took a look and keeps on ticking. But if you have to explain it, it's no good. It stands alone. Took a licking, stop ticking. That's all I needed to say. Okay, get me out of this.

Bruce Betts: Okay. We move on to another question and I tried to be creative here. I learned some things, came out of the rabbit hole of the question and you should be thankful to Planetary Society COO Jennifer Vaughn, who argued that I should use the simpler of the two versions that I came up with.

Bruce Betts: So, this is the, oh, it's so easy and obvious version of the trivia question. What do the following have in common, the Venus atmosphere near the surface and some coffee decaffeination processes? Go to

Mat Kaplan: Wow. It's not so easy for me.

Bruce Betts: Yeah. I was kidding.

Mat Kaplan: You have until Wednesday, July 8th at 8:00 AM Pacific Time to get us the answer to this one. Someone is going to win ... I'll give you a choice. You can either have The Earth Book, by Jim Bell, From the Beginning to the End of our Planet, 250 Milestones in the History of Earth Science. As you heard I have it and I think it's terrific.

Mat Kaplan: Or the one I haven't seen yet, but sounds great, Hubble Legacy: 30 Years of Discoveries and Images by Jim Bell with a foreword by our recent guest, John Grunsfeld, the guy who visited it three times up there in space. All right, we're done.

Bruce Betts: All right, everybody, go out there, look up the night sky and think about what type of ancient relic mechanism you'd like us to find. Thank you and good night.

Mat Kaplan: Why is everybody looking at me?

Bruce Betts: We're digging up Mat.

Mat Kaplan: He's Bruce Betts. He is the chief scientist of the Planetary Society, who joins us every week here for What's Up.

Mat Kaplan: Planetary Radio is produced by the Planetary Society in Pasadena, California. And it's made possible by its perfectly exposed members. You can get in on this picture at

Mat Kaplan: Mark Hilverda is our associate producer. Josh Doyle composed our theme, which is arranged and performed by Peter Schlosser. Stay safe and well. Ad astra.