For our 100th episode, our first and most frequent guest is back, Dr. Melissa Rice. Right before quarantine, we entertained a live audience at WWU with stories of missions past and details about the future Mars Rover launching this July.
If you would like to learn more about Dr. Rice’s work you can visit https://wp.wwu.edu/mars/
You can follow her on Instagram @westernmartians & Twitter @martian_mel
[upbeat electronic music]
Dr. Regina Barber DeGraaff: Welcome to the hundredth episode of Spark Science. I’m your host, Regina Barber DeGraff, and I’m an astrophysicist at Western Washington University. The guest for this episode is to Spark Science what Steve Martin is to SNL. She was our first guest, a NASA Rover team member, a planetary scientist, and my office mate, Dr. Melissa Rice. Back in March, days before the quarantine, we held a live show at WWU to talk about the next mission to Mars. We also reminisced about the good times, our last live show together, the Cassini mission wake, and the history of the Mars missions. We hope this episode will provide you with some mental escape when you can sit back and imagine travelling to The Red Planet.
So welcome to a live recording of Spark Science. I’m your host, Regina Barber DeGraaff. I’m an astrophysicist here at Western Washington University. I’m super excited to introduce you to our guest. Some of you might already know her. She is WWU’s resident Martian, NASA scientist, associate professor in physics, astronomy, and geology, Dr. Melissa Rice. I’m gonna clap for you.
[Applause.]
Dr. Melissa Rice: Thank you! I’ll clap for me too!
Dr. Regina Barber DeGraaff: So welcome back to the show. This is your 8th time, or something like that.
Dr. Melissa Rice: Something like that! Been here from the beginning!
Dr. Regina Barber DeGraaff: From the beginning! You’ve seen us crawl out of the mud.
Dr. Melissa Rice: From when you were recording in the Spark Museum!
Dr. Regina Barber DeGraaff: I was! I was recording in the Spark Museum. That’s right.
Dr. Melissa Rice: And transmitting from the roof of the Spark Museum out for like a 3-block radius in downtown Bellingham.
Dr. Regina Barber DeGraaff: Yeah! So for those of you who don’t know, the Spark Museum did have a local radio station– they’ve since separated– KMRE.
Dr. Melissa Rice: But now you’re on the internet.
Dr. Regina Barber DeGraaff: That’s true.
Dr. Melissa Rice: Everyone in the world is listening.
Dr. Regina Barber DeGraaff: Yeah! Yeah, I used to look at who downloads our shows and it would be like 1 in Russia–
Dr. Melissa Rice: Yeah!
Dr. Regina Barber DeGraaff: –one in Taiwan, and I’m like, “that’s my cousin!”
[audience chuckling]
Dr. Regina Barber DeGraaff: It was!
[audience chuckling]
Dr. Regina Barber DeGraaff: But we wanted to bring you on the show today. You’ve been on the show multiple times. You were at the march for science, so when we say you’ve been on 8 times, it’s not like me and you talking. Sometimes it’s events we go to. We had a wake for the Cassini mission. Do you wanna tell the audience? They might be interested in that fun fact. Before we go to Mars, let’s go in the wayback–
Dr. Melissa Rice: Yeah, sure! Before we celebrate the birth of a new mission…
Dr. Regina Barber DeGraaff: Let’s talk about death!
Dr. Melissa Rice: Yeah, the Cassini spacecraft had been orbiting Saturn for many, many years.
Dr. Regina Barber DeGraaff: Yeah. It was launched when I was in.. I think undergrad, here.
Dr. Melissa Rice: Yeah!
Dr. Regina Barber DeGraaff: At the turn of the century I went to school here.
Dr. Melissa Rice: Yeah and it was just getting its science underway when I was an undergrad, and had continued through what, two years ago when we threw the wake. And the mission was going to end. It couldn’t continue anymore, and so then rather than just have the space craft kind of fizzle out–
Dr. Regina Barber DeGraaff: Or just drift off into space.
Dr. Melissa Rice: Or drift off into space. Or die and drift off and crash into Saturn’s moon Enceladus and create a warm little pond contaminated with earth life, potently, the team decided to give the mission a grand finale and plunge it, kamikaze style, into Saturn. So the spacecraft burned up through Saturn’s atmosphere and transmitted what data it could on the way, deeper than we had ever probed before. And in celebration of that, the death of the mission, Gina and I threw a Irish wake style party–
Dr. Regina Barber DeGraaff: We bought cow lilies and everything, and we got like–
Dr. Melissa Rice: We had a coffin. It started off very somber, and we had eulogies–
Dr. Regina Barber DeGraaff: Yup.
Dr. Melissa Rice: We had local scientists come and weep. We wore black and veils, then a band came out–
Dr. Regina Barber DeGraaff: The David Bowie cover band.
Dr. Melissa Rice: And we had a dance party.
Dr. Regina Barber DeGraaff: Yeah. And that episode is on our website if you go to sparksciencenow.com. You can also go to my Instagram, Spark Science– it’s not sparksciencenow, it’s just Spark Science– and you can see pictures from that wake. You also brought in a tiny like replica of the Mars rover, and we tied a veil over–
Dr. Melissa Rice: That’s right! I forgot about that! That was brilliant.
Dr. Regina Barber DeGraaff: Yes.
Dr. Melissa Rice: We’re so smart.
Dr. Regina Barber DeGraaff: You’re the best. Speaking of the Mars rover and its sadness then, now it’s happy. It’s celebrating its new sibling, I would think.
Dr. Melissa Rice: Yeah. That’s right.
Dr. Regina Barber DeGraaff: New child, sibling, what would you say?
Dr. Melissa Rice: I’d say sibling.
Dr. Regina Barber DeGraaff: Okay.
Dr. Melissa Rice: Yeah, or maybe granddaughter. And I say daughter because we refer to all of the rovers as “she.”
Dr. Regina Barber DeGraaff: Right.
Dr. Melissa Rice: Because they’re ships of exploration, so we tend to speak of the, when we do use gendered language, as “her” in that tradition from maritime exploration. So yeah, I would say this is the next generation rover. The tiny rover that we put the veil on and that
joined us for the wake of the Cassini mission, this rover is a replica of the actually twin rovers, Spirit and Opportunity, which were launched towards Mars in 2003. They landed in 2004, 3 weeks apart, on opposite sides of the planet. They were designed to last for 90 days and Spirit’s mission lasted 7 years, and Opportunity’s mission just ended last year, about a year ago.
Dr. Regina Barber DeGraaff: And how are you– young undergrad– how are you associated with any of these missions?
Dr. Melissa Rice: When I was an undergrad, the Mars exploration rovers Spirit and Opportunity and launched and landed in my senior year, and I hear a presentation about what these rovers were doing in their first weeks on the surface of Mars, and I was smitten. I said, “That’s what I gotta do, I wanna be part of Mars exploration somehow.” And I knew that the missions were only supposed to last 90 days. I was a senior in college. By the time I would get to graduate school and get a chance to work on these missions I thought they’d be long-dead and over, and I’d just be working with the data while the rovers were sitting there rusting on Mars.
But I applied to go to graduate school, I got in, and by the time I got there, the rovers were still going. They had long outlived their warranty by that point, but the whole 6 years that I was in graduate school, both rovers were still operating. Spirit rover ended its mission my last year, but I was able to be part of the ongoing operations, part of the team of people who decided what pictures the rover was going to take, part of the people looking at the new images getting downlinked from the rovers every day and assessing them, and there were some times when I’d get up really early and see the data– I’d be refreshing my login to the NASA Jet Propulsion laboratory’s servers looking for when the new data arrived, and sometimes I would see a new image arrive and open it up and have a pretty good confidence that I was the first person in the world to see that new image of Mars.
Dr. Regina Barber DeGraaff: Wow.
Dr. Melissa Rice: Maybe see a new landscape on Mars. So that– you know, you don’t go back from that. So I was hooked. And then, when I graduated from Cornell University with my PhD, this rover– the big one on the left– the curiosity rover was about to launch towards Mars. And that was the next generation rover. So what we’re talking about today though is the next generation after that, so the granddaughter of Spirit and Opportunity, and that rover… you know when you look at this projection of how each of NASA’s Mars rovers has grown bigger and beefier, but the Mars 2020 rover actually looks exactly like the curiosity rover that came before.
Dr. Regina Barber DeGraaff: We don’t wanna get much bigger, right? I mean the complications of making something even larger is huge, right? Or no?
Dr. Melissa Rice: Oh yeah, because you have to have a bigger rocket, because it ways more. You have to get more mass off the surface of the earth. And then, when it’s hurtling through
space, you want to slow it down so it lands on Mars with a nice feather touch, and it’s really hard to lang on Mars, because Mars doesn’t have much atmosphere. We use a big parachute, but the atmosphere is so thin that there’s not enough air for that parachute to slow it down.
Dr. Regina Barber DeGraaff: Mmm.
Dr. Melissa Rice: So the parachute only slows the rover down to about 200 miles an hour, and then we have to do something creative to slow it down from 200 miles an hour down to maybe a couple miles an hour for a nice, soft landing. The little guys, the Spirit and Opportunity rovers, those used air bags, and they were enshrouded in air bags, and the air bags bounced and bounced and bounced, and then rolled to a stop. Curiosity, and now the Mars 2020 rover, they have to use a different landing system because they’re so big. These big white rovers are about 2000 pounds, and if you were to use air bags, they would just pop the air bags and crash into the surface.
Dr. Regina Barber DeGraaff: What’s the height? I know there’s a picture of you standing next to one of these.
Dr. Melissa Rice: Yeah, so the Spirit and Opportunity rovers, they are about 5 and half feet tall, so about exactly my height. You know, the perfect height.
[laughing]
Dr. Melissa Rice: The big rover, the Curiosity rover on the left, that one is about 10 feet tall. It’s got a big mast, it’s kind of looming over you, and its arm that stretched out there, just the arm itself is 7 feet long, and it has a suite of instruments on the end of it that is the size of a lawn mower, and those instruments alone weight 200 pounds. It’s so big and heavy that in the test bed after it was built here on earth, the rover couldn’t lift its own arm up, and it’s designed to work in Martian gravity, which is about 40% of earth’s gravity, so on Mars it can lift up the arm no problem, ’cause it feels 40% lighter. But here on earth, it can’t even lift its own arm.
[upbeat electronic music]
Dr. Regina Barber DeGraaff: This is Spark Science and we’re talking to Dr. Melissa Rice about what the next rover on Mars will be doing. The words “rover poop” were used.
Dr. Melissa Rice: As scientists, we tell the engineers what we want, and why we want it. We say, “we want to be able to take pictures in these number of wavelengths, because we want to be able to detect these types of minerals on Mars,” and then the engineers have to figure out how to make that happen.
Dr. Regina Barber DeGraaff: Right.
Dr. Melissa Rice: So they really have the hard stuff, we just get to dream big and make demands, and they actually have to make it happen. This is a graphic of the new rover, and I’m calling it the Mars 2020 rover out of habit, and it says “Mars 2020” on these slides, because these slides are old, meaning that they’re more than 6 hours old. Earlier today, NASA announced what the name of the new rover is going to be. Anyone hear what that was? A couple of people? Yeah, yell it out!
Audience: Perseverance.
Dr. Melissa Rice: Perseverance! Yeah, we gotta start getting really excited about this, because we’re going to be calling this rover Perseverance or Percy–
Dr. Regina Barber DeGraaff: Like in Harry Potter. You had actually texted that to me earlier today and I thought you were just giving me like encouragement.
Dr. Melissa Rice: I know! [laughing]
Dr. Regina Barber DeGraaff: I was like really confused. I was like, “Perseverance? Cool Melissa, thanks.”
Dr. Melissa Rice: Yeah! [laughing]
Dr. Regina Barber DeGraaff: I’ll get through that class!
Dr. Melissa Rice: Yeah okay, so this is Perseverance and this graphic is highlighting what is different about this new rover from the previous rover, Curiosity.
Dr. Regina Barber DeGraaff: Oh the arm is different, right?
Dr. Melissa Rice: The arm is different–
Dr. Regina Barber DeGraaff: It looks like more of a hammer.
Dr. Melissa Rice: Yeah the instruments on the end of the turret are different. The main difference is that sample catching system. What that is is a system for storing rocks that are drilled and collected as drill cores from the arm, and that sample caching system is going to be a system for the rover to use its arm to put a rock core into a fancy sample tube, hermetically seal it, document it, and then kind of poop it out onto the surface and leave that carefully selected rock sample in a sample tube on the surface, so the rover can drive away, leave that rock there, and then hopefully, fingers crossed, NASA will fund another mission to go to Mars and collect those samples.
Dr. Regina Barber DeGraaff: And pick up the poop.
Dr. Melissa Rice: Pick up the poop, poot ’em in a doggy bag–
Dr. Regina Barber DeGraaff: Right.
Dr. Melissa Rice: –and bring it back home.
Dr. Regina Barber DeGraaff: Shoot it up into a rocket.
Dr. Melissa Rice: Yeah.
Dr. Regina Barber DeGraaff: So it is going to go to various sites and get all like different samples?
Dr. Melissa Rice: Exactly. Yeah, yeah and early on in the mission planning NASA had all sorts of concepts for maybe we would have a fancy space bucket, and we put all of the samples as we went along into that space bucket, and then just leave that whole bucket full of the sample tubes someplace on Mars, and the next mission would just have to pick up that one thing. But that poses a lot of risks, because what if the rover is collected all of these lovely curated samples, it has the perfect cache ready to go, and then something happens to the rover? It gets stuck somewhere, it slides down a cliff, who knows what could happen. It would take those samples with it, and then all of that work would have been for nothing. So this what’s called distributed caching, or as I like to call it “rover poop”, that method allows the rover to drop the sample, keep moving, and then it doesn’t have to carry the risk of having that very valuable rock sample still in its clutches.
Dr. Regina Barber DeGraaff: Right. I think there was other things we wanted to talk about. Basically, what do you do now with the current rover, and what do you hope to do with the next rover?
Dr. Melissa Rice: Yeah so cameras are kind of my game. On the curiosity rover–
Dr. Regina Barber DeGraaff: Yeah. Me too. I’m camera rich.
Dr. Melissa Rice: The curiosity rover has 17 cameras.
Dr. Regina Barber DeGraaff: Oh, well you’re better.
Dr. Melissa Rice: So I’ve got you beat. The cameras that I work with are the color cameras, the ones that are on top of the rover. There’s a big cyclops eye at the top. That’s actually a telescope with a laser, and that is an instrument called chem cam, or on this rover it’s going to be called super cam, that blasts little holes in rocks with a laser, and then the telescope looks at the plasma– the glowing plasma– that’s emitted just for a split second after the laser zaps it. That’s a technique called laser-induced breakdown spectroscopy. Right underneath that big cyclops eye, these two eyes, those are the cameras that I work with. They’re color cameras,
so they take color pictures, just like your smartphone or your point and shoot camera, but they can also take pictures in a number of different wavelengths of light beyond the visible wavelengths, out in longer wavelengths that the human eye is not sensitive to. So Mars is the red planet. Mars is actually more of the brownish-orange planet, but it looks very monochrome in the pictures that we get, and so the colors that we prefer to take pictures with on Mars are the colors where Mars is actually more colorful, which happen to be at longer wavelengths than your or my eyes can see.
Dr. Regina Barber DeGraaff: I remember talking to you when you first started here at Western, and you were telling me, “I want to know if there was any water on Mars at one point.” “I want to know if there still could be.” Like, those were the questions.
Dr. Melissa Rice: Yeah. Those are questions that we have been answering in various forms for the past 10-20 years, and now the questions are not so much was there water on Mars. We have abundant evidence that there was water on Mars in different forms, but our questions now are about what were those forms like? Was that water good enough to drink? Was it neutral water or was it highly acidic? Was it fresh water or was it highly salty? Was it the kind of water that life likes to inhabit or was it the kind of water that would require extremophiles, or lifeforms kind of on the edge of what we know life can sustain.
Dr. Regina Barber DeGraaff: Like those bears. Like the water water bears.
Dr. Melissa Rice: Water bears! Yeah. Tardigrades.
Dr. Regina Barber DeGraaff: Yes. Those.
Dr. Melissa Rice: Love those.
Dr. Regina Barber DeGraaff: There was something about the wheels as well.
Dr. Melissa Rice: Yes. So, to the trained eye, or someone who’s been really paying attention through all these slides, you’ll notice that the wheels on this rover are slightly different than the wheels on the previous curiosity rover. First of all, the pattern of the treads is different. And these wheels are slightly narrower as well, and the reason for that is because Curiosity’s wheels, as Curiosity’s been driving around on the surface of Mars for the past 8 years, Curiosity’s wheels have a bunch of holes that have been punched in them. The rocks on Mars at curiosity’s landing site turned out to be sharper and pointier than rocks we had encountered elsewhere on Mars. And the rocks on Curiosity’s landing site, that’s a really old site. Those rocks have been sitting there for maybe three and a half billion years, and over three and a half billion years the winds have been blowing and sculpting those rocks into nice, pointy little pyramids. And as the rover wheel drives over that sharp, pointy pyramid, it pokes holes in the wheels. So for these wheels, we’ve had to thicken them up, but to not add mass to the rover as a whole we had to make them narrower so they can be fixed.
[upbeat electronic music]
Dr. Regina Barber DeGraaff: This is Spark Science, and we’re speaking with NASA scientist Dr. Rice about the realism of Mars in the movies.
Dr. Regina Barber DeGraaff: What’s the back part? The kind of butt area?
Dr. Melissa Rice: The butt, yeah. That is the power source. So the big difference between this rover and the previous generation ones, like the small little Sojourner rover, the Spirit and Opportunity rover in the middle, there are none of those black, shiny solar panels. So the new rover is not solar powered. It has that big butt behind it, which is its own nuclear power source. So that’s called an RTG. What it really is is a pellet of plutonium– plutonium 238– and that decays fairly quickly. It has a half-life of 88 years, but what that means is it’s decaying fast enough that it’s emitting a lot of heat as it decays, and that heat we can capture and convert to electricity, and that’s what’s used to charge the batteries.
Dr. Regina Barber DeGraaff: And it did show up in the movie The Martian.
Dr. Melissa Rice: It did! They dug up the old one–
Dr. Regina Barber DeGraaff: Which takes us to our pop culture section.
Dr. Melissa Rice: Yeah. Good segue.
Dr. Regina Barber DeGraaff: What is the accuracy of that movie and what isn’t? I remember we talked about that?
Dr. Melissa Rice: Yeah, yeah, so overall, best Mars movie ever made in terms of scientific accuracy.
Dr. Regina Barber DeGraaff: Mars Attacks second.
Dr. Melissa Rice: Mars attacks, well I mean that’s really more accurate but we’re not allowed to talk about that.
Dr. Regina Barber DeGraaff: Right. I’m sorry. Just blew your cover!
Dr. Melissa Rice: So from the perspective of a camera and spectroscopy nerd, they nailed the colors of Mars. It was really well-done. It was the right kinds of brownish shades of dark and light browns, a little orange. They didn’t way overdo it with the super red Mars. So that was great. The color of the sky, for the most part, was great as well. It’s kind of a pinkish-salmonish color sky during the day–
Dr. Regina Barber DeGraaff: Except for…
Dr. Melissa Rice: –except they missed the sunset! And I think I’ve said this every time I’ve been on the show.
Dr. Regina Barber DeGraaff: I love it.
Dr. Melissa Rice: I won’t let it go. The best part about the day on Mars is the sunset, because the sky on Mars is red normally during the day because there’s lots of red Mars dust in the atmosphere. But right at sunset, and also right at sunrise, that’s the only time of day when briefly sunlight is traveling through a thick-enough column of atmosphere that you can see the scattering processes that we see in the earth’s sky during the day. So only at sunset and sunrise, for a brief period of time, do you see a blue sky on Mars. And they did not get that right in The Martian, but you know.
Dr. Regina Barber DeGraaff: Not Oscar-worthy.
Dr. Melissa Rice: They did pretty well overall. But really the egregious thing that was wrong with The Martian was the whole premise of the whole movie.
[laughing]
Dr. Regina Barber DeGraaff: Tell us more about that.
Dr. Melissa Rice: Yeah so in the beginning of the movie, we’ve all seen it, but for anyone listening at home who maybe hasn’t–
Dr. Regina Barber DeGraaff: Spoiler alert.
Dr. Melissa Rice: –spoiler alert.
Dr. Regina Barber DeGraaff: We’re gonna be talking about the movie.
Dr. Melissa Rice: There’s a big storm on Mars, things are blowing around, you see like big rocks flying through the air–
Dr. Regina Barber DeGraaff: Things being stabbed.
Dr. Melissa Rice: Communication tower tips over and it blows and it stabs Matt Damon through his suit. That’s the whole setup to the whole movie. Kind of an important plot point, otherwise there’s no reason to leave him stranded there on Mars. So I understand why they had to do it, but the problem is Mars’ atmosphere is not very thick, so there’s just not much air, not many air molecules to blow around. So even if the winds are howling, super high speed winds–
Dr. Regina Barber DeGraaff: It’s gonna be doing like this.
Dr. Melissa Rice: — there’s just, yeah, not enough pressure, ’cause there aren’t enough air molecules going fast to actually push something over. So that communications tower would have been just fine. It’s a really hard problem on Mars just to blow single grains of sand in air because the pressure is so low, let alone the like big hunks of debris we can see flying around in the opening scene of the movie.
Dr. Regina Barber DeGraaff: I’m gonna let the audience ask their questions.
Audience member: What did you discover in your dissertation?
Dr. Melissa Rice: In my dissertation I worked with the Spirit rover.
Dr. Regina Barber DeGraaff: So which one was that on the… oh it’s the one with the small solar power–
Dr. Melissa Rice: That’s the medium one.
Dr. Regina Barber DeGraaff: Solar powered one, yeah.
Dr. Melissa Rice: Solar powered rover.
Dr. Regina Barber DeGraaff: I guess the little one is too.
Dr. Melissa Rice: And Spirit– so all of our rovers have 6 wheels, and as Spirit was in its second year, so already past its 90-day warranty, but its front-right wheel broke, and what that meant was that the rover was stuck. So it was really hard for the rover to drive forward ’cause it was kind of pushing that wheel into the dirt, so the rover spent the next 5 years of its mission driving backwards, kind of dragging that dead wheel through the dirt.
Dr. Regina Barber DeGraaff: Oh wow.
Dr. Melissa Rice: Now how this led to my dissertation was that it made the rover drive really slow. It seemed like a big bummer, but as that wheel was digging this trench through the dirt, it surprisingly discovered that there were some really strange soils buried just a couple centimeters below the surface. Right when I showed up to start graduate school, my advisor said, “You wanna do something with Mars? Here, figure out what these soils are about. We just got these pictures down last week.”
Dr. Regina Barber DeGraaff: Wow.
Dr. Melissa Rice: And these soils were bright white, they were bright yellow. Those are weird colors on the reddish-brownish-orange planet. So my thesis was mainly about analyzing
those soils with the cameras–
Dr. Regina Barber DeGraaff: That no one had seen before.
Dr. Melissa Rice: –that no one had seen before, trying to figure out what they were. And with the cameras we saw that they contained a lot of water, and then the story that emerged was that these were hydrothermal deposits, so these were silica and sulfate materials, the kinds of minerals that form in places like Yellowstone. So this is our very strong evidence now for an ancient hydrothermal system on Mars, and that site was so exciting that it was proposed as one of the possible landing sites for the next rover, Perseverance, the new 2020 rover.
Dr. Regina Barber DeGraaff: Did it win?
Dr. Melissa Rice: It did not. Where the perseverance rover is going to land is a spot called Jezero crater, and it’s a spot where there is a beautifully preserved river delta inside an ancient what’s now dry crater lake. It does drive, just very slowly, too. So about the length of a football field, that’s one good day of driving, where the rover’s doing nothing but driving. So really slow, like 3 centimeters a second.
Dr. Regina Barber DeGraaff: Wow. I think Julia has a question.
Julia: Hi. Yeah, I have a question about the drilling. How does this drill– how deep is it going to go? And then, how does that compare, if at all, to any drills on other missions?
Dr. Melissa Rice: Yeah that’s a great question. Yeah so the drill is really just gonna scratch the surface. We’re talking about maybe 5 inches deep. That’s not very deep. So you know if we’re really interested in searching for life on Mars, ideally we’d want to go deeper, and go to places that are protected from the harsh UV radiation and everything bombarding the Martian surface. So if we wanna find organic molecules, evidence of life, we might have to go deeper with another mission. The European Space Agency, they have a mission called ExoMars. The Rosalind Franklin rover is set to launch this year, so around the same time as this new rover. That mission, their biggest objective is to search for life as deep as they can go, and their drill is supposed to go as deep as 2 meters, so closer to 6 feet depth. So that would be great, but you know the drill that we have here is the same depth of drill as what the Curiosity rover has done, and we’ve seen that it can certainly go beneath, you know, the top layer of dust and the top layer of the rock that’s been altered. We don’t have a full understanding, though, of where deep in the Martian crust might be the best place to look for life.
Audience member: Could you talk more about how they chose the specific crater for Perseverance, cause you said there was a competition.
Dr. Melissa Rice: Right, right, so there was a competition over a period of several years. Anyone in the world can purpose where on Mars a rover should land. So at an initial meeting, there were 38 different sites that were proposed, mostly by scientists who work in this
business, but you know, we had a high school student purpose a landing site, and that high school student was able to come to the meetings and present his arguments, just like all the PhD scientists. So a really open process. I love how NASA does this. So 38 sites were proposed and vetted by the engineers. Those were down-selected to 8. I had a site in the running at that level. Another chapter of my PhD thesis was on a site on Mars called Eberswalde crater that also has a beautiful river delta preserved in it, a little more beautiful than Jezero crater, if I have to say.
Dr. Regina Barber DeGraaff: I’m just gonna side with you.
Dr. Melissa Rice: I was advocating for that site and then they down-selected from 8 sites to 3, and Eberswalde crater came in number 4, so it didn’t make the cut.
Dr. Regina Barber DeGraaff: Oh wow.
Dr. Melissa Rice: So then there was a lot of debate over the last 3 sites. Jezero crater won in part because it’s close enough to midway in northeast Syrtis that we can envision a scenario where if the rover lives as long as the previous rovers have, we can drive up and out of the crater and go to some of those other terrains as well.
Dr. Regina Barber DeGraaff: Was it a very heated argument?
Dr. Melissa Rice: Oh yes. It always is. People with red faces and screaming and… I’ve seen scientists lose their cool in this process. They’re passionate.
[upbeat electronic music]
Dr. Regina Barber DeGraaff: We’d like to thank Dr. Melissa Rice for being our guest for episode number 1 and episode number 100, and always being up for anything. If you’d like to learn more about Dr. Rice’s work, you can visit wp.wwu.edu/mars. You can follow her on Instagram @westernmartians and on Twitter @martian_mel. Spark Science is produced in collaboration with KMRE and Western Washington University. Today’s episode was recorded at Western Washington University in Bellingham, Washington. Our producers are Suzanne Blais, Robert Clark, and myself, Regina Barber DeGraaff. Our audio engineers are Zerach Coakley, Julia Thorpe, and Aaron Howard. Script support by Ariel Shiley. If you missed any of the show, go to our website, SparkScienceNow.com. And if there’s a science idea you’re curious about, send us a message on Twitter or Facebook at SparkScienceNow. Thank you for listening to Spark Science.
