Planetary Radio: Space Exploration, Astronomy and Science - Marc Rayman’s Dawn Mission Update

Episode Date: January 19, 2016

The Dawn Mission Chief Engineer Marc Rayman returns for another report on the ion-engine powered mission, now orbiting 240 miles above dwarf planet Ceres in the Asteroid Belt.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Mark Raymond on the Dawn mission, this week on Planetary Radio. Welcome to the travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. Dawn's Chief Engineer and Mission Director returns with news that the ion-engine driven spacecraft is now closer to dwarf planet Ceres than ever. Mark will share the latest science. Commercial space access reached two more milestones in the last few days. We'll talk about them with Bill Nye.

And we're giving away one of the coolest prizes ever in the What's Up Space Trivia Contest with Bruce Betts. Emily Lakdawalla is the Planetary Society's senior editor. Emily, there is more news from Cassini this week. Tell us why it is bittersweet. Well, we got toward the end of 2015, the beginning of this year, some really wonderful icy moon images from Cassini. And of course, I've always loved processing these pictures.

Writing about Cassini is the first kind of science writing I did for the Planetary Society. But it's bittersweet because Cassini just flew past Titan, which it does a lot, but this particular Titan flyby tilted the orbit up and out of the ring plane. And Cassini has to be in the orbit of the ring plane for frequent moon encounters. This marks the very last time that Cassini will ever be in a ring plane orbit from now until the very end of the mission. It's going to be diving up and below the rings. And of course, that isn't a terrible thing. Cassini will be getting fantastic views of the rings from here on to the end of the mission. But this is pretty much it for dense moon encounters. There's a couple more moon flybys coming up this year. There will be some really good tiny moon, ring moon flybys toward the very end of the mission. But we're kind of done with the Voyager era surveying of all of the moons of Saturn, and that's pretty much it. So that's what made me sad.

The beginning of the end, perhaps. This is a nice way to mark it, though, in your January 15 blog entry. I want to start with this gorgeous image of Enceladus, which has Saturn beneath it. It's really stunning. And I love the fact that even though it's only showing a tiny sliver of Enceladus' surface, you are seeing it from the north to the south. And in the north, there's this ancient crater terrain. And in the south, it's all this wrinkly, ridgy terrain. It really shows you all that Enceladus has to offer, even in this slivery view. And it is Titan that Cassini will get to take a few more looks at as it adjusts its orbit even further.

There is one of these wonderful before and after images that you've included in this January 15 blog. Tell us about this. You know, I always like to show moons as they would appear to your eye if you were there. And when you do that for Titan, Titan is quite striking, but it's also bland because it's just this orange-colored ball with a little sliver of blue around the edge.

So I always like to show what you can see on Titan's surface. And with a pair of images that was processed by Val Clavins, I was able to do that, allow you to peel away the atmosphere and see the features on the surface, including my favorite region of Titan, the Fensal-Aztlan area, which is these dark lowlands that are filled with sand dunes that just makes a striking sideways H figure on the face of Titan. I am sliding it back and forth right now, going from before to after, and just below it is this map of these features on Titan that you've created. I recommend taking

a look. It's a January 15 entry. Thank you, Emily, very much. I'll talk to you again next week. Thank you, Matt. She is our senior editor, planetary evangelist for the Planetary Society, Emily Lakdawalla. Up next is the CEO, our boss at the Society, Bill Nye, the science guy. Bill, we look to the news again this week, and it's again about the commercial space efforts by several companies. Orbital, SpaceX, and Sierra Nevada. These are companies that take money from NASA to make rockets, and the goal is to make them cheaper, and not just rockets, to get transportation, especially to the International Space Station.

And this is new space. This is the next wave, the next cycle of rocketry. This is to say, instead of being built exclusively by space agencies, the space agency is hiring these companies to produce these rockets much more hands-off fashion. Everybody figures it will lower the cost of getting to space. And it's exciting. I mean, SpaceX is very high profile. As we speak, just yesterday, they yesterday, SpaceX successfully got a Jason satellite, the Jason 3 into orbit. This is a satellite that monitors the sea surface. And they tried again to

land their lower stage on a barge. The ocean was rough and apparently one of the landing gear didn't lock into place. And so it fell over. But they're getting closer and closer every time. And this would make space access to low earth orbit cheaper. And then I just, between us, Matt, and I guess all the listeners, Sierra Nevada's dream chaser is just a cool, it's a cool ship. It looks like a space shuttle times 0.3. And so I'll just tell you, my old aeronautics professor when I was in college talked about you can put your winged spacecraft on top of the rocket. You can put it in a sense in front of the rocket if you're going to launch from a runway, but be very careful about mounting it on the side of the rocket, which is what the old space shuttle was. And sure enough, the Dream Chaser is on top of the rocket. So it's a winged spacecraft that's

going to land on a runway, but it takes off or launches from a conventional style rocket. And so this could greatly lower the cost of bringing stuff back down from space. Parachutes landing on the steps in Eurasia or landing in the ocean near North America, it's fine, but it's a lot of messing around. It's much nicer to have it land right there on a runway. So I'm excited about this. It shows that NASA's taken some chances and these contractors are taking chances and this will lower the cost of low Earth orbit, which will advance space science and exploration. That's our thing, Matt. It's exciting. I can't wait to see that dream chaser come back from low-Earth orbit and land on a runway.

And don't forget orbital. Don't forget that blue origin lands on its tail, just like Flash Gordon, like what's happening right now. Lots of cool stuff going on. Thank you, Bill. Thank you, Matt. He's the CEO of the Planetary Society. Bill Nye, the science guy. We're going to go to a guy who's not on as often as Bill, but a lot. Mark Raymond is going to give us

an update on the Dawn mission now orbiting very close to Dwarf Planet series. Mark Raymond is more than the chief engineer and mission director for the Dawn mission. He's also a terrific communicator. He shares his Dawn journal with us at planetary.org. The latest installment was posted on New Year's Day, and it had big news from the only spacecraft that has orbited two destinations in our solar system. It spent more than a year at protoplanet Vesta in the asteroid belt between Mars and Jupiter.

It then fired up one of its three ion engines and departed for Ceres, by far the biggest object in the belt. Mark recently joined me via Skype from his office at the Jet Propulsion Lab near Pasadena, California. I started by asking him about Dawn's health, now that it has been in space for well over eight years. Dawn is in very good shape. It's doing beautifully in its lowest altitude orbit at dwarf planet Ceres, collecting lots of data and doing everything we're asking it to. I'm very happy with it. doing everything we're asking it to. I'm very happy with it.

So how much closer is the spacecraft to Ceres now than when it first arrived? Let's see. When it captured into orbit, it was about 38,000 miles away. And now it is only 240 miles away. So it's quite a bit closer. In fact, it's even a little bit closer to the surface of Ceres than the International Space Station is to Earth. Wow, that's impressive. I mean, didn't you say in the blog something like 1,500 times closer? And that's to say nothing of how much closer it is than any telescope on Earth. That's right. It's 1,500 times closer to Ceres now than it was at the beginning of 2015. And as I mentioned in the blog, more than a million times closer to Ceres than Earth is. And that's why we send spacecraft to distant planets, right? You can get perspectives, views, that are essentially impossible to get from Earth. This allows us

not only to take measurements that are truly impossible from the surface of Earth because of our atmosphere and other constraints, but also simply to get much closer views that are otherwise unattainable. Yeah, there is nothing like getting up close and personal. There is also in the blog this wonderful sequence of images that literally zooms from Ceres being a little tiny sphere in a field of black to the eye-popping walkabout close-ups of the surface that you are getting now. How many images are we getting? I don't know. How many have we gotten over like the last year from Dawn as it's closed in on this world? Well, let's see. We've probably gotten, I don't know what the count today is, but I think as well over 17,000 pictures of series at this point. And at this point, we're returning an average of more than a thousand pictures a week. Wow. And in fact, that isn't even Dawn's highest priority.

But that's just an illustration of how fantastically productive the spacecraft is being. Yeah, and we're definitely going to talk about all that other science. But those images, they amaze everyone, as you say in the blog. By the way, I'm ready to join you for a hike across that terrain. You talk about that one image that just makes everything pop out. It's fantastic. Willie would be a heck of a hike, wouldn't it? It would be, and I'm ready to take it with anybody who'd like to join me.

All right, so they keep pouring in. I want to assure people we're going to keep teasing you for a few more minutes. We will talk about those bright spots. But first, let's go ahead and talk about the science. Tell us about those instruments and other than the cameras and what they are telling us about this dwarf planet. Well, one of the other instruments is a combination actually of two, a visible mapping spectrometer and an infrared mapping spectrometer. And these spectrometers are devices that break up the light into its constituent colors,

just as a prism breaks up light into literally all the colors of the rainbow. When we do that, the light carries the signature of the material that it's reflected from. It's like a fingerprint. signature of the material that it's reflected from. It's like a fingerprint. So we break up not only the visible light, but the infrared light as well. And infrared light, of course, being light that we can't see with our eyes, but that our instruments can detect, just as there are wavelengths of sound that we can't hear, but the dogs can detect. So we've used this infrared mapping spectrometer to study the minerals that are on the surface and found that one class of minerals there are called phyllosilicates. In them is the material ammonia, which is something many people are familiar with.

And this is very important because ammonia is a very common molecule in the solar system, but it tends not to occur in the inner solar system close to the sun. So this is perhaps telling us either that Ceres formed much farther from the sun than it is now, perhaps even beyond the orbit of Neptune, and then its orbit was distorted so that it came in to where it resides now, or that it formed where it is now, but that other material from the outer solar system drifted in and fell to Ceres' surface. So we don't yet know, but this is going to give us important clues about the evolution of the early solar system. And that, of course,

is the whole idea of the Dawn mission, because we want to understand the dawn of the early solar system. And that, of course, is the whole idea of the Dawn mission, because we want to understand the dawn of the solar system. Yeah, I'm glad you mentioned the ammonia, because you got an interesting question from a reader of this January 1st Dawn Journal blog entry. He commented on your mention not just of the ammonia, but of water ice found on Ceres. And then he asked you about the astrobiology significance of this find out. No one's suggesting there's life on Ceres, I don't think, but you shared his wonder about this angle. That's right. And Ceres has been of astrobiological interest for some time.

In fact, I wrote about this in one of my blogs in August of 2014. We know it has water. There's good reason to believe it has organic materials. We now know it has ammonia, which maybe it's not so obvious because most people don't think of it, is that sunlight falls on Ceres. And while Ceres is up to three times farther from the sun than Earth, that's still close enough to the sun that warming from the sun contributes to the chemistry on Ceres and internal heating as well from radioactive materials that were incorporated into the dwarf planet when it formed. So it may have many of the ingredients that are necessary for chemistry related to that of life. So sometimes it's called prebiotic chemistry. And in fact, that's the reason that we will never let Dawn come in contact with Ceres. We're not allowed to because we want to protect that pristine environment from our organically dirty spacecraft.

Mark Raymond of the Dawn mission, now orbiting dwarf planet Ceres. He'll tell us more after a short break. This is Planetary Radio. This is Robert Picardo. I've been a member of the Planetary Society since my Star Trek Voyager days. You may have even heard me on several episodes of Planetary Radio. Now I'm proud to be the newest member of the Board of Directors. I'll be able to do even more to help the Society achieve its goals for space exploration across our solar system and beyond.

You can join me in this exciting quest. The journey starts at planetary.org. I'll see you there. Hey, hey, Bill Nye here. I'd like to introduce you to Merk Boyan. Hello. He's been making all those fabulous videos, which hundreds of thousands of you have been watching.

That's right. We're going to put all the videos in one place, Merk. Is that right? Planetary TV. So I can watch them on my television? No. So wait a minute. Planetary TV is not on TV? That's the best thing about it. They're all going to be online. You can watch them anytime you want.

Where do I watch Planetary TV then, Mark? Well, you can watch it all at planetary.org slash TV. Welcome back to Planetary Radio. I'm Matt Kaplan, and I'm talking once again with Mark Raymond, Chief Engineer and Mission Director for the Dawn mission that is now circling just 240 miles, or 385 kilometers, above the surface of Ceres, out there in the asteroid belt between Mars and Jupiter. Before the break, Mark was telling us about the instrument payload aboard the spacecraft.

There is another very powerful instrument on Dawn called GRAND. Seems like a very apt name for this device. It is. It is an apt name, but the instrument is actually quite humble despite that name. It's got a terrific attitude. And it actually is two instruments in one. It measures gamma rays, which are very high energy photons. So beyond visible light, which is composed of photons, there's ultraviolet light, X-rays, and by measuring the number and the energy of these particles, Grand can reveal to us the elements that occur on Ceres. That is, which members of the periodic table that are of interest to geologists occur on

the surface and in the material within a yard or so of the surface. And I think this is a really cool instrument. I just think it's really neat that measuring this nuclear radiation coming from more than 200 miles below the spacecraft allows us to determine the elemental composition. Many spacecraft have gamma ray spectrometers and many have neutron spectrometers. Many also have both. So it isn't unique that Dawn carries it. But, of course, the reason for that is because this is a very powerful tool for scientists to use to understand the composition of extraterrestrial bodies. We have also talked on the show about how the radio signals from other spacecraft,

including Cassini at Saturn, are used to reveal the inner structure of worlds. How is Dawn doing the same thing? Well, that's a good question. We use the radio signal to make very, very accurate measurements of the spacecraft's orbit. And we do that using a couple of techniques. One is the Doppler effect, which most people are familiar with. In fact, they're listening now. So if they think of a siren that goes, you know, that change in pitch as the source of the sound moves by you is because of the compression of the sound waves and the expansion as the source moves toward you and away from you, the compression of the wavelength and then its expansion. And the same thing happens with the radio waves as the spacecraft flies toward or away from Earth as it's revolving around Ceres.

And we have other methods as well to use the radio signal to track the spacecraft. So what that tells us is what its orbit is. And its orbit is determined by how all the different mass arranged within Ceres is pulling and tugging the spacecraft around. So by plotting the orbit, we can work backwards to figure out where all that mass must have been in order to cause Dawn to move the way it has. And so that lets us look deep, deep inside Ceres and know how its interior is arranged. And so that's data that we're taking right now, and we will use that to determine its interior structure.

All right, Mark, I think we've kept everyone in suspense long enough. Has the mystery of those so-called white or rather bright spots been solved? The mystery hasn't been solved, but we've made tremendous progress on it. And the reason I say it hasn't been solved is it's not definitive, but we do have now what we consider to be a very good explanation that we're continuing to test as we get more data. And that is that what happened is an impact occurs, that is a rock from space, a small asteroid, say, crashes into the surface of Ceres, excavates material from underground

that includes subsurface briny water ice. So underground there's ice, or perhaps there's liquid water underground, but it has dissolved salts in it. That water gets to the surface and even if it's initially liquid, it freezes quickly and then exposed to the vacuum of space, the water sublimes. That is, it transfers from being a solid to a gas. So the individual water molecules disperse and leave behind the salt that was dissolved. And that salt is more reflective than most of the rest of Ceres. And so you can think of these bright regions as salt flats.

They reflect more light. And so what we're seeing is the residue from water that made its way to the surface and then departed and left its salts behind. So we are closing in on this. It sounds like a pretty good theory is finally in place. And I said up front, you know, it's probably better to call these bright rather than white. Why is that, Mark? Well, the reason people called them white is because our early pictures were black and white, and these looked white. But of course, white is really a description of color. And until we had color pictures, we couldn't tell whether they were truly white. And now that we do have color pictures, we know that most of them have a very,

very slight blue tint. It isn't a tint that your eyes would discern. Nevertheless, they're not truly white, but they're bright, and that's what matters. You know, speaking of this very faint color, there is also in the January 1st blog this image of Ceres literally rotating under dawn, and we see the entire dwarf world, but it's in false color. And that is something that comes up periodically on the show as well. But tell us why use of false color is so useful to scientists. Well, the reason is related to what we were discussing earlier, and that is the details of the way an object reflects light contain information about the nature of the material, its composition or its structure. And so even when there are details that are too subtle for our eyes

to detect, our instruments can detect them. And so then we exaggerate it when we display it so that then our eyes can see it. And it helps draw our attention to areas of different composition or different structure. You close this blog entry with a little of your personal history with Ceres. When did you first see this dwarf planet? I first saw it when I was 12 years old. And normally I don't put that much personal information in my blogs, partly because I feel like this is a mission of humankind and I'm trying to write it for everybody. But I just couldn't resist mentioning just how exciting it is having seen this. In fact, as I think I said in there, as a starry-eyed youth and now as a starry-eyed adult, getting to be involved in a mission to explore this dwarf planet. It's very exciting, Matt. And not just for you, Mark, but for the rest of us who are following the mission and look

forward to more updates and more revelations from the Dawn spacecraft. Thank you so much for making another of these appearances on Planetary Radio, and I look forward to the next one. And I do too. I always appreciate your interest. Thanks, Matt. Mark Raymond of the Jet Propulsion Lab is Chief Engineer and Mission Director for DAWN, the spacecraft that has made history with its exploration of protoplanet Vesta and now has moved on, thanks to its ion engine, to Dwarf planet Ceres, the largest object in the asteroid belt. It's now orbiting just 240 miles or 385 kilometers above that world. Mark is a JPL fellow, and he's the only person to have received

both the Exceptional Technical Excellence Award and the Exceptional Leadership Award from the lab. If you ever get the chance to hear one of his public talks, don't miss it. Time once again for What's Up on Planetary Radio. Here's Bruce Betts, the Director of Science and Technology at the Planetary Society. I've never said it that way before. Welcome back. It was an exciting moment that we'll look back upon in this week of space history next year.

Yeah. This will be, mark your calendars, everybody. It's coming again soon. Tell us, what's up? Beautiful example that we live in a solar system where the planets all orbit in roughly the same plane. You can see in the predawn sky, going east to west, Venus, Saturn, Mars, Jupiter, all in a nice, roughly, line because of that orbiting in the similar orbital plane. Venus, super bright, low in the east. Jupiter, sneaking into the evening sky, so you can check it out in the east in the evening.

Looking very, very bright, coming up around 9 or 10 in the evening. On to this week in space history. 1962, John Glenn became the first American to orbit the Earth. Did you say Earth? I did say Earth. Okay. I like that. How's that spelled?

E-A-R-F? Yes. Yeah. All right. Before you go on, since Random Space Fact is next, I wanted to read you this note from Paul Johnston in Rochester, New York. He had an answer for the trivia question this week. He says, that was said about as excitedly as that last week's Random Space Fact.

Get it together, Bruce. So your fans want to hear more oomph. I don't know if I can do that. Random Space Facts! The Andromeda Galaxy, which is the closest major galaxy to the Milky Way, is about 25 Milky Way diameters away from the Milky Way galaxy. That's actually closer than I would have guessed. It is.

That was kind of the feeling I thought until I remembered that the Milky Way galaxy is 100,000 light years across. So it's really not a stone's throw, but it is in comparative location. I agree with you. I'm feeling some territoriality. I think Andromeda should back off. Back off. Yeah. I think it's doing just the opposite, but we've got a few billion years to deal with that.

All right, on to the trivia question. I asked you, what is the third most abundant atom in the galaxy by mass fraction, whereas hydrogen and helium dominate? What's third in the galaxy? Huge response for this and so many lovely comments from listeners. Here's what we got from Sid Rajput in Temecula, California. He said, running third in this race, Oxygen, our friend.

That is correct. Our friend Oxygen. So congratulations Sid. You are going to get that big prize package, Planetary Radio t-shirt, a 200-point itelescope.net astronomy account for that worldwide nonprofit collection of telescopes, and a set of Year in Space wall and desk calendars from Year in Space at yearinspace.com. Nathan Quinn, West Deptford, New Jersey.

He put it this way. Oxygen takes the bronze medal in the all Milky Way mass off, though it beat out all other competitors in the Terran regional qualifiers. Tim Peterson, Clarksville, Arkansas. He wanted us to remember that it's not just oxygen, but specifically oxygen 16, that isotope that largely comes at the end of helium fusion in stars when they're about to move on, I guess, to fusing other stuff? Yes, it is the standard, normal, most common oxygen isotope of oxygen-16. Here is the winner for coolest observation this week. Kevin Hecht in Pleasant Plains, Illinois. We've

heard from Kevin many times. He said, I was going to say something about the universe's preference for elements with even atomic numbers, having just discovered it myself, but I see that it has been noted by others and it makes sense. He's right. The universe, just like Star Trek movies, prefers elements with even numbers. What else you got, man? Just one more, because I recognize this quote that Anders Brolin in Sweden sent in, and I've always liked this quote. It's from the great Frank Zappa, the great late Frank Zappa. Some scientists say the major building block of the universe is hydrogen because it's the

most plentiful element. But my theory is the universe is made out of stupidity because it is more plentiful than hydrogen. Which isotope? Stupidity 14, I think. All right.

As you will recall, the Pioneer spacecraft leaving the solar system contained plaques, messages to the universe from Earth. On the Pioneer spacecraft leaving the solar system contained plaques, messages to the universe from Earth. On the Pioneer spacecraft plaques, Earth's position is shown relative to 14 what? What are the 14 things that are displayed to give Earth's relative position? Go to planetary.org slash radio contest. Good question and a great prize.

You can go to planetary.org slash radio contest. Good question and a great prize. First, I will tell you that the deadline is Tuesday the 26th. That's Tuesday, January 26th at 8 a.m. Pacific time. And here it is. We did this once before, but now it is new and improved. It's ISS above. This is the great little self-contained box that is programmed to tell you when the International Space Station is flying above you. But not only that, when LightSail is in orbit, as we are still planning for hopefully later this year, it will become LightSail Above. And you can also hook it up to a monitor.

LightSail Above. And you can also hook it up to a monitor, and it has just an incredible array of wonderful information about ISS and who's on it. It really is a tremendous thing from our friend Liam, and he has made it available to give to whoever wins this next

contest. And you can learn more about ISS Above at, where else, ISSAbove.com. Coolness. We've had some very nice surprise packages lately. We really have. And I didn't even see the need to throw in a t-shirt with this one. But if somebody says pretty please, I'll put that in too. All right, everybody, go out there, look up in the night sky, and think about lint rollers. Thank you, and good night.

Oh, man, do we need those? We just did a long trip with the dog in the car yesterday. He's Bruce Betts, the Director of Science and Technology for the Planetary Society, and he joins us every week here for What's Up. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its lofty members. Danielle Gunn is our Associate Producer. Josh Doyle wrote the theme music. I'm Matt Kaplan. Clear skies.