Planetary Radio • Jan 16, 2019

Flying the Skies of Saturn’s Moon Titan

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Elizabeth "Zibi" Turtle

Planetary Scientist at Johns Hopkins Applied Physics Lab and Dragonfly Principal Investigator

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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

Imagine soaring over what may be the solar system’s most Earth-like world, if you ignore the chill. If funded, the nuclear electric-powered Dragonfly will do exactly this. Principal Investigator Elizabeth “Zibi” Turtle shares her enthusiasm. Emily Lakdawalla reports on Chang’e 4, China’s pioneering lander and rover on the far side of the Moon. Bruce and Mat answer a question that had no answer till New Horizons flew by Ultima Thule days ago. That’s part of this week’s What’s Up.

Dragonfly over Titan (artist's concept)
Dragonfly over Titan (artist's concept) Image: John Hopkins APL
Dragonfly Mission Concept
Dragonfly Mission Concept Dragonfly is a dual-quadcopter lander that would take advantage of the environment on Titan to fly to multiple locations, hundreds of kilometers apart, to sample materials and determine surface composition to investigate Titan's organic chemistry and habitability, monitor atmospheric and surface conditions, image landforms to investigate geological processes, and perform seismic studies. It was selected as one of two possible missions for the next New Frontiers launch opportunity in 2017.Image: NASA

This week's question:

What 180 kilometer diameter crater did Chang’e 4 land in, and who is the crater named after?

To submit your answer:

Complete the contest entry form at or write to us at [email protected] no later than Wednesday, January 23rd at 8am Pacific Time. Be sure to include your name and mailing address.

Last week's question:

When is the next total lunar eclipse after this month’s that will be seen from Earth?


The answer will be revealed next week.

Question from the January 2nd space trivia contest question:

Is 2014 MU69 or “Ultima Thule” a binary, a contact binary, or none of the above? (No one will know till after New Horizons sends back higher resolution images!)


2014 MU69 or Ultima Thule turns out to be a contact binary object.


NOTE: This automated transcript is currently being edited by a human. Check back soon for updates.

[00:00:00] A flying machine for Saturn's moon Titan this week on planetary radio.

Welcome. I'm at Kaplan of the planetary Society with more of the Human Adventure across our solar system and beyond they call it dragonfly and there has never been anything like it. Will it get the chance to fly across the frigid yet surprisingly earth like surface of Saturn's moon. We'll learn more from the Project's principal investigator Elizabeth Zippy Turtle.

It was a question. No one could answer when Bruce vets asked it two weeks ago. Now we're ready to resolve that space trivia contest quiz about New Horizons recently visited. The planetary Society is Jason Davis is keeping up with China's great success on The Far Side of the Moon. You can read his work in the planetary Society blog at planetary dot-org Jason's colleague senior editor Emily locked Walla [00:01:00] is also on top of this Mission.

I talked with her at planetary Society Headquarters A few days ago. I passed by your office a little bit earlier today and there you were working away at Photoshop creating something which is now available to. Everybody online and it's pretty terrific. We have some really amazing video from China showing The Descent of the Lander chonga for to the surface and a lunar far side, and then even better for me the deployment of the Rover.

It's little wheels rolling out onto these tracks the tracks being lowered like a forklift to the lunar surface, and then just instantly the Rover drives right off leaving tracks in the very powdery dust of the lunar surface. It's just amazing. I guess you. Did it out but our colleague Jason who has been writing regularly about Chung F4.

He'll be blogging about this. He already has, you know, there's been so much space stuff going on in the last couple of weeks Jason and I have been working on each other's stuff. We've [00:02:00] got the chonga for landing. We've got the osiris-rex going into orbit the MU 69 flyby. It's just been overwhelming in a good way.

But I'm also kind of tired well, and you didn't mention in sight but you have written about it because inside. Is just going great guns when we had that wonderful live launch event. It sounded like it was going to be a lot longer before the real science started to come back. But I guess they're pretty close.

They're very close. We're definitely not quite at real science yet. They still have to do some things like putting the very important wind and thermal Shield over their instrument to keep it protected from changes in temperature. And yes Martian wind that would upset the delicate balance of the seismometer, but the instruments.

Have gotten back their first data and it's looking spectacular the scientists are so happy any word about when they will start drilling down below the surface that will happen. Probably late February. They'll start doing that. It's not exactly a drill. Remember. It's a self [00:03:00] hammering mold the kind of just pings its way down.

It's going to be kind of fun. So much going on as you said, it's a big time for Planetary Exploration. It really is and it's just a pleasure to have so many International collaborators. I'm on Twitter and I see, you know at the end of my day, Japan and Australia are waking up overnight. I see Europe come online and Just As the World Turns.

We have data coming in from from agencies all over the world, and it's just a it's a great time. Thanks Emily. Thank you Matt. That's Emily locked Walla senior editor for the planetary Society. And part of that means that she's in charge of the planetary report which you can now check out online.

The whole magazine is there in a great online format and see what's happening all over the solar system as well as the terrific writing that goes into that magazine each month. We'll talk to her again soon. In [00:04:00] 2020 the next Mars Rover from the US will carry a flying machine to the red planet. This tiny helicopter will mostly be a proof-of-concept a far more ambitious.

Cousin is being planned at the Johns Hopkins University Applied Physics lab if it is funded and successfully reaches Saturn's clouds shrouded moon. Titan dragonfly will allow us to explore far more of this tantalizing world than a Rover could hope to cover one of the highlights of my recent visit to APL was the chance to sit down with the leader of the dragonfly effort.

Elizabeth Turtle goes by zbi a nickname. She picked up as a toddler when she. Quite say Elizabeth Zippy has joined us a couple of times previously. But this is her first visit as principal investigator for both dragonfly and the [00:05:00] camera system that will be aboard the Europa Clipper spacecraft when it leaves for that other moon in the early to mid 2020s.

ZD Elizabeth, welcome back to planetary radio. Thanks very much pleasure to be here again and nice to be doing it for the first time face to face. Thanks to the fact that I'm here to cover this wonderful Mission this encounter with Ultima to lie, but I'm getting all this other wonderful material, which I guess is just terrific evidence of all the great things happening here at APL.

Yeah, they're a lot of a lot of exciting things going on and especially as you mentioned with the New Horizons flyby of ultimate too late. That's been that's been really exciting and we're anxious to see what they got as we speak. We are only about three hours away from seeing the latest and greatest that has been sent back by the spacecraft.

So, where are you going to be in the room again looking for that new higher res image? I hope so I hope so it'll be very interesting to see what they what they see [00:06:00] out there in the far reaches of the. Our system. Yeah, can't wait but you're a busy person. You have a lot going on and we're going to talk about just a couple of those things that are keeping you busy right now beginning with the one and I've been trying to think of how to talk about this because everybody that I know.

Myself included is so excited about this mission that is still just a candidate that is waiting to see if it's going to be funded and you know where the planetary Society every mission that reaches this stage. The dragonfly has reached. We would love to see get out there into the solar system, but there certainly is something especially captivating about sending a flying machine to this.

Absolutely stunning world of Titan. I don't think you'll disagree. No, I won't there are certainly a lot of important places in the solar system to explore and we're [00:07:00] very excited to be at this stage in The Proposal process for New Frontiers and have the to be able to work on the dragonfly mission in this at this point.

There's a lot of work that's been done in the the phase a. Study that we've were just completing and we were really hoping to be able to get back to tighten. You said it's a New Horizons Mission, excuse me, New Frontiers Mission New Horizons was the first face. Yes in that class and this is because it's a cheaper than one of the most expensive missions.

I mean things like curiosity or the James Webb Space Telescope. Right or Europa Clipper the flagship or you can see me the flagship class mission right New Frontiers is the The Next Step. So the mystery from its the mid-range. It's the next step up from Discovery with the discovery Mission stand exactly at the lower level.

Yeah still big Investments, of course, and so we would expect NASA. [00:08:00] To do a great job of evaluating these how do you make the case for dragonfly? I mean, of course one of the things that we know from past experiences that NASA likes to go with proven technologies that seemed safer because they have worked in the past and dragonfly is pretty Innovative.

It is it's an Innovative application. Of existing technology and that's that's really what we've leveraged here in developing. The mission concept dragonfly would send a rotorcraft Lander to tighten and spend most of its time on the surface Making Science measurements, but would be able to fly from place to place so that we can get to multiple sites to make those measurements.

It is an Innovative exploration strategy, but the technology that we use to do that. Is is all technology that exists and has been proven here on Earth or on Mars. And so we're able to leverage [00:09:00] that and take advantage of the technological advances that have already been done and then apply those to tighten.

Other than calling it by the Mission named dragonfly. How do you describe this device this flying machine. I mean I have heard people call it a quadcopter, but it's really double that. It's really an octocopter that gives people the sense that it's got 8 arms, and it's actually got four arms with two rotors on on each.

So technically it's an x 8 rotorcraft, but sometimes we'll call it a dual quad copter or a mostly we refer to it as a rotorcraft Lander so you. Give me because when I first heard about this, I thought okay, I know drones. I got one for my birthday a couple of years ago their little tiny guys and it's only very recently that I've learned how big this craft is going to be give us an idea of its Dimensions.

It's a similar size to Mars. We have a similar type payload, we have four instruments. And so now do you mean [00:10:00] like spirit and opportunity class or more like curiosity? It stands a little over a meter high. Okay meters across. Yeah. So it's a I mean, it's a yeah, it's somewhere in the mix. Yeah the Lander sizes.

So it is much larger than the the drones. That one is used to playing with her. Yeah, it's Rock Yard, it carries everything with it like. Mars rovers, so we have an M mrtg power source, radioisotope thermal generators the same thing. That's the same thing as curiosity and right. Yeah, exactly. And so we have that and the payload and everything comes with us.

It's a single unit that moves from place to place. So this is not going to be a light spacecraft at least in terms of its or if wait because I mean you've got the the RTG that's got a lot of shielding. You've got all these instruments but you can get away with this on Titan apparently, right, right.

The gravity on [00:11:00] Titan is about a seventh of the gravity here on Earth. The other thing that makes aerial exploration such a possibility on Titan, of course is its atmosphere and the atmospheric pressure the surface of Titan is one and a half times that. The surface pressure of the surface of Earth so it's actually easier to fly on Titan than it is on Earth.

I have heard people saying that a human properly insulated could fly on Titan you just flap your arms with the right Wing's attack. Yes, if you if you had wings and a good sweater and be able to fly on time. You ever read the great Robert Heinlein story. I think it was called the Menace from Earth and there are big lava tube type cavities on the moon and this is when people are flying around on the moon exactly this something to think about for the distant future I suppose but for now this idea of a flying machine is I called it on tight.

The [00:12:00] answer to this is probably obvious. But why will it be so useful to be able to do more than just crawl across the surface as we do on Mars so we know from the Cassini observations of Titan that it has a very varied geography. Titan is actually surprisingly earth like it has. With the atmosphere it has a lot of atmosphere surface interactions.

There are sand dunes except it's Organics and there's actually a methane cycle like our water cycle here on Earth. And so they're methane clouds and methane rivers and you know, even methane lakes and seas, so it has a wide diversity of surface features and wide distribution of types of material on those on the.

For us and what we want to be able to do is get to different places to be able to understand the chemistry of Titan in these different environments because this is [00:13:00] fundamentally a mission to understand Prebiotic chemistry. And so we want to be able to understand how materials have interacted how chemical compounds have interacted in different places on Titan where the history has been.

So to be able to get to areas that are tens or hundreds of kilometers apart. We really need to be able to use this technology to fly. It gives us just a much longer range to be able to travel. You said you're going to be looking for Prebiotic conditions. Maybe I'll ask first how your instruments will do this.

And so maybe talk about the instruments that you plan to carry right there for instruments that dragonfly would carry one is the mass spectrometer. This is a mass spectrometer very similar to the Sam instrument that is on Mars right now on curiosity, right? But so this is one of the the applications of current technology to the Titan environment.

So we would be able to sample material from the [00:14:00] surface into the mass spectrometer to measure details of the chemical composition. And this is one of the reasons we want to be able to go to different places is to see what how the chemistry differs from place to place on the surface. So we you have a scoop or a drill drill.

Yeah, and we can use pneumatic transfer because we have an atmosphere now, so you'll just. Like pneumatic tubes and apart just like exactly yeah. Yep fascinating. Okay, which also makes me think of Planet vac the yes technology that the planetary Society has been supporting development side and I believe I believe it for that you're working with honeybee robotics.

We sure are it's their concept. Yeah, and that's the the same the same team. We're working with on dragonfly. How cool I did not know that that had come up. All right another check for the planetary Society there what other instruments. There's a gamma ray and neutron spectrometer. This allows us to measure the bulk Elemental composition in the area under the rotor [00:15:00] craft its complementary to the mass spectrometer, which will measure very detailed chemistry of specific sites.

We get a different sense of the material components available for that chemistry with the gamma and neutron spectrometer. One of the things we have to do a bit differently from other applications is an instrument that's been used on other spacecraft like the messenger spacecraft and the gamma ray Neutron spectrometer is also being developed for the psyche Mission that's in development for Discovery.

But one of the differences for Titan is it because we have an atmosphere that Shields the surface from cosmic rays. So we actually have to bring a neutron generator with us. Oh, so the right generate neutrons to be able to sense the the products of those reaction because it asteroids it's the cosmic ray impacts that give you those make those neutrons and and gamma rays fly off of objects, right?

Okay, exactly. Very very interesting the other two instruments. We have a suite of cameras. [00:16:00] You better that's exactly exactly and we'll be able to take images both on the surface and in flight, and then we have a suite of atmospheric meteorology sensors and geophysical sensors including seismic sensors another.

Technical factor which I find fascinating about this spacecraft because it is a spacecraft even though it's yes nicely. A flying machine is that you you will be able to relay through anything. There won't be anything else in the saturnian system to get help get your signal back to Earth dragonfly is going to have to communicate directly write we do director of communication from the surface.

We have a high gain antenna we're able to do communication directly from the surface of Titan fairly efficiently. What kinds of organic molecules do you hope to find the you know, there is a lot of speculation. Not just that. We will find very complex [00:17:00] Organics on Titan. But that as you said you're going to be looking for Prebiotic stuff, which this would certainly fall into that classification a lot of people still speculate on.

Well, if you did have to figure out how life could have evolved on a body like Titan. Here's a possible model is dragonfly going to help us with that. So we know that there is very complex organic chemistry occurring on Titan. We have measurements from the Cassini spacecraft, which actually sampled the top part of Titan's atmosphere and measured very complex molecules at the even in the very upper reaches of the atmosphere and of course all of those molecules.

Fall down through the through the atmosphere and there's this this Rich Haze, which makes it difficult to see the surface. Yeah, but provides this incredible chemical like deposit on the surface of Titan. It all just falls out onto the surface of Titan There Are Places on Titan. [00:18:00] I mentioned that there you know that there's a methane cycle.

There's liquid methane on the surface. And so that's of course one way that you can get, you know have a solvent to interact with these these complex organic molecules one might call it a methane-based primordial soup. Exactly. Yes. So there's a there's the possibility for chemical progress in a methane-based system the surface or the the crust of Titan is Water Ice Titan is a.

In world, like many of the satellites in the outer solar system. There's a deep liquid water ocean and it may be possible for there to be material exchanged between the Surface and the ocean so for Organics to get down to the ocean or for water to come to the surface in the form of cryovolcanism.

There are some hints of that in the Cassini data, of course Titan is also been subject to impact. And with a water ice crust such [00:19:00] impact events would melt the crust and now you've got a liquid water reservoir that can persist for long periods of time. There's also these operas opportunity or these opportunities on the surface for the Organics to have interacted with liquid water.

We know from laboratory experiments that if you combine the types of organic materials we have on Titan with liquid water. You can get amino acids Etc. And so you can get into this these Prebiotic chemical molecules. This is only making me more excited about what you may be able to find. How are you going to pick?

Where this machine will fly to I mean what will be your targets the initial Landing will be in the inter Dunes Titans low latitudes the equatorial region have these vast sand Seas Seas of organic sand dunes and we know this from Cassini exploration. So we've characterized [00:20:00] these regions. Well, we know that Dunes are made of organic sand particles.

We don't know how they. That's an ongoing question. But we do expect that the dunes will have gathered material from a wide range across Titan similar to some of the sites that have been explored on Mars where material is, you know, we can get a grab bag of materials. And so similarly the dunes may offer that widely sourced organic material from across time.

But the other reason the the dunes are a good place to explore initially is that in between the dunes there? Are these very flat broad inter Dune areas, which not only make for very nice landing sites. Yeah, but also allow access to material with a Water Ice. And so in very close proximity you have both this Rich organic material and material with a water ice component.

And so that allows us to get to two different types of two different types of materials in a [00:21:00] short period of time because they'll be both accessible at the at the initial Landing site from there. One of the things that's particularly exciting about dragonflies that we can scout future Landing sites in advance.

We actually will take off go out and Scout a new area come back. So we're connaissance flight so we can do a reconnaissance flight. Wow, exactly. And so then we'd come back to the same Landing site transmit the data decide where we want to go next what we want to explore next. I'll expect they'll be lots of energetic science team discussion.

I bet ya about about that but we what we would do in the long run is have a leapfrog exploration. Where once we know where our next Landing sites going to be we would fly to the toward that Landing site, but then overshoot go past it Scout a new area and then come back to the previously scouted Landing site.

And that way we have this very [00:22:00] efficient strategy to be able to make progress across the surface and also scout each Landing site in advance. Is there reason to Land close to or on the beaches of tighten the shorelines of some of those lakes and seas? I mean, you know, of course I'm thinking of my t-shirt surf Titan there have to be some risk in that as well.

The the Seas and lakes are certainly very interesting places to explore. There are a couple of reasons why we're focusing on the solid material on the surface. Rather than exploring the lakes and seas directly as previous proposals. So the time mission that was proposed to explore ligeia mare a for example the boat the boat.

Yes, Cassini actually did a very good job of measuring the lakes and the Seas the Cassini radar was actually able to penetrate to the. Of [00:23:00] the the Seas and measure their depths. Yeah, and that also puts constraints on the the material the liquid material in the in the lakes and seas. So we have a pretty good understanding of the liquid composition and what we don't understand after the the tantalizing hints that Cassini and the Huygens probe which landed on the surface of Titan gave us we don't understand at this point is the chemistry of the solid materials.

We have a very basic we know that they're different. Reels and we know some have a water ice component etcetera, but it's at the very high level. And so it's the solid materials that we really it's a big gap in our understanding of Titan is the nature of the composition of the solid materials the other complication with the lakes and seas.

Is that the timeline for this New Frontiers call with that timeline launch would be in 2025 and we would arrive at Titan and 20 30. So that's conveniently actually almost [00:24:00] a year almost exactly a year after the Huygens probe descended down through the atmosphere. So from a conveniently it gives us atmospheric truth.

We know what the atmosphere was like at that season on Titan. So that's very that's very good for planning our our Landing for understanding what the the conditions will be like, but at that time in Titans year. It will be Northern winter the lakes and seas which are primarily at the high Northern latitudes will be in Winter darkness.

And if the sun isn't up the Earth isn't up and the director Earth communication strategy requires us to be able to see Earth with the Lander, of course because at that distance Earth from the sun are not too far apart same part of the sky exactly. Right, so it's you know, initially we looked at that and said well we won't be able to go to the lakes and seas because of the season but then we also have this scientific imperative to really understand the the chemistry of the solid surface on time for the [00:25:00] future.

Would it be interesting to explore those shorelines which I assume we may find and who knows maybe dragonfly will at least image some of these perhaps there's the equivalent of tide pools, right? Yes, it would be very interesting place to explore dragonfly with the MMR TG. That means that there isn't necessarily a constraint.

The mrtg power degrades slowly the power output degrade slowly but we use it to charge a battery. So so one can certainly start to you know, dream of longer extended missions where one can go further and further afield and of course, it's exciting to think about having a way of Dipping dipping one's toes in the shorelines.

Yeah. I'll say this spacecraft. It's got to be pretty tough. It's got it withstand the pressure of the cold and then the other thing that occurred to me was. It's going to have to live through probably some [00:26:00] rain storms. Right? Well we know from we know from Cassini what the seasonal weather patterns are like on Titan because Cassini was able to survive to explore the saturnian system for such a long time for 13 years.

It was almost half a Titan year because he got there when Huygens landed it was late Southern summer the equivalent of January on Titan and the. Seany Mission lasted until late June in Titans year, so we really got to see how the weather changes and at the time when Cassini arrived all of the clouds the the one that South polar rain event we observed that was all at the South Pole.

There was one other rain event that Cassini observed and that was at lower latitude. After that, he was actually well after the northern vernal equinox on Titan and that would be several years after dragonfly [00:27:00] arrives. So we don't expect there to be rain events at the latitude that we're exploring during the mission lifetime.

If there were rain, it wouldn't be a problem rain on Titan. It's the same temperature as the as the you know, the lender everything would be equilibrated on the outside. Of course, the raindrops actually fall very slowly on Titan they fall at about the speed of snowflakes on Earth because the gravity's solo.

So it would actually be pretty interesting to observe but we don't expect that to be something that happens in the in the season that we're that we were on active in the nominal Mission. I just such an amazing world we know from Cassini. The radar images how rich visually this this surface is I am very excited about the possibility of getting back these camera shots of canyons and dunes.

And yeah, I you you clearly agree. Yeah. Absolutely. It's a it's a [00:28:00] very Earth-like place. It's a very familiar place and that's what we've that's what we've seen from Cassini and from you know from the the ones seen that Huygens was able to. Serve on the on the surface and being able to get to a variety of different geologic settings is of course extremely compelling and being able to understand how the, you know, the different interactions of geologic processes atmospheric processes on Titan how they all work.

And of course to understand the chemistry. We really need the context of the environment. And so that's one of the reasons that we've chosen the payload we have because we need not only the specific chemistry at the Landing sites, but to understand the landing site. So we need the atmospheric context and the geologic context what has brought the materials to do the places that we explore.

And then of course the [00:29:00] geophysical context the nature of the surface ground Truth for Cassini measurements and even listening for Titan Quakes with a with a seismometer the same way that that Insight is about to be doing on Mars, which is very exciting. All right, so I certainly love the idea that you're going to get so much science out of these images complementary science, but it's really just those exciting pictures that I want.

I want to see of this of this world. I reluctantly turn away from dragonfly. I'll leave me one more question. When will we know if you are allowed to move on to the next phase so we just turned in the concept study reports. That's the another the big product from the phase a study. There will be a site visit in the spring of 2019.

The review, you know, the reviewers have the proposal at this at this point. They will come ask us questions at the the site visit to discuss details with them at that point after that at some point in the [00:30:00] early summer. Hopefully NASA will be making a decision. Best of luck. Thank you. All right now onto a mission that is a sure thing at least in terms of getting it off the ground.

I know I shouldn't say that right you're allowed to knock on wood the Europa Clipper, which you are deeply involved with and we talk with people about this Mission a lot Bob pappalardo and others and you're in charge of the the Imaging system. Yes, they are of Imaging system or ice as we call it which consists of a narrow-angle camera and a wide-angle camera so comp two complementary.

Is that will observe the the surface of Europa at a wide range of scales to be able to constrain a variety of different aspects, you know from geophysics to surface geology to sir? For plumes so I think back as you mentioned plumes to your mention of the possibility of cryovolcanoes on Titan. We already know they exist on Europa.

That's the point right? Well, there's [00:31:00] certainly some very tantalizing evidence that there may be active plumes or be at times active plume eruptions on your rope. I guess. It's more of a sure thing. It did sell it and sell it as yes. There's ongoing cryo volcanic plume eruptions that Enceladus there.

Like I said a number of lines of evidence for that at Europa, but we don't quite yet have the the same, you know, the same direct observations of the plume. Potential pollutants that Europa that we've had at Enceladus but we hope to be able to do that in the Europa Clipper Mission has a large suite of instruments all of which are designed to be able to study various aspects of the plumes if they're there and of Europa regardless of whether or not they're their plumes another beautiful world, your cameras will be bringing sending us beautiful images of this place as well.

It's really exciting [00:32:00] to be looking forward to getting back to Europa being able to observe the Europa as a system in that it has, you know, potential plumes the the surface geology how the The Ice shell Works potential exchange processes, you know through the ice shell to the the subsurface open ocean.

And with the with the cameras, of course, we get to look at that at a variety of scales from the very high resolution, you know meter scale to Global mapping of the. The world of Europe as a world that has Europa Clipper the the planning of this Mission benefited from previous missions there. I'm thinking particularly of the one that still underway Juno which is doing a pretty good job of surviving in that nasty radiation environment.

Yes, any of the any of the spacecraft that have been in or gone through the Jovian radiation environment provide us [00:33:00] information about the radiation and that's very useful for for designing. Spacecraft for understanding how much shielding we need for the you know for the instruments or other components of the spacecraft?

Absolutely. I haven't talked to anybody for a while now about the current status of Europa Clipper, but I take it things are moving along. Yes, things are things have been moving along at a rapid Pace instruments are actually all coming up on the critical design reviews at this point starting starting this.

Getting through those and then and then really getting into building the flight equipment very exciting times around our solar system. Yes. There's a there's a lot going on. You've been at this for a while, you're getting these opportunities now to explore in ways that we've never. No one even dreamed of until fairly recent years and now some of them at least are becoming reality.

I just think of how your field of planetary science has [00:34:00] changed compared to its. You know, it's Genesis years when even the term was still being. Defined by people like Carl Sagan. You must be a pretty good feeling. It's a amazing to look back and see how far we've come and how much we how much we know now and how many questions right every every new Step brings brings new questions with it going back to the the Cassini Mission and.

When Cassini arrived we only knew that there were large areas on the surface that were somewhat brighter and somewhat darker, you know in the infrared that's that was all we had was the remote telescopic observations at you know the scale of. Thousand kilometers across the surface and and in the span of almost the blink of an eye Titan went to the from that to an incredibly familiar place with you know, where we know the surface geology and we know the geography [00:35:00] and we've gotten to observe the the seasonal cycle of weather and so did to think of just how quickly you know place can go from being.

Unknown to being familiar is amazing. And of course we've done that for many of the the worlds in the outer solar system in the last just the last couple of decades. It's it's been a great adventure. I hope we keep it up absolutely wish you the greatest of success with these projects and everything else said to that you're up to using.

Thanks very much and pleasure to talk to you. It really has thanks Elizabeth. Zippy turtle is principal investigator for the Europa Imaging. System and the dragonfly Mission she is a planetary scientist in the space exploration sector at the Johns Hopkins University Applied Physics lab tougher.

What's up on planetary radio? The chief scientist of the planetary Society is here with us. That's Bruce Betts. Welcome. Welcome. Welcome to you mad. How you [00:36:00] feeling not as well as I would like which probably people can hear if they haven't noticed already during the show, but the show must go on and so we carry on.

You're a Trouper. Thank you. That's what I wanted to hear. I was trying to come up with some space themed thing, but I'll leave it as Showbiz. Tell us what's the show in the skies space Trooper? Haha. That's opposed to a star trooper, sir. Yeah, exactly. So up in the sky. We've got a we've got that total lunar eclipse happening on the night of the 20th to the 21st and the maximum.

Total eclipse will be at 5:12 UT on the 21st. That's 2112 Pacific Standard time for us. The total lunar eclipse will be visible throughout most of North America South America the Eastern Pacific the Western Atlantic Western Europe. And even in D Stern Europe, it'll just and Eastern Africa [00:37:00] because it's visible in Western Africa.

And even in the Eastern parts of that they'll still catch the end of the. It'll be cool. What's hope for Clear weather across the world? It's a worldwide sensation nearly. It's half a worldwide sensation anyway, and then in the pre-dawn, we've got that Jupiter Venus dance going on. So Venus super super bright Jupiter.

Super-bright they will be very close together on the morning. That's the pre-dawn east on the morning of the 22nd of January or Jupiter will pass Venus from night to night heading farther up and getting above Venus to its upper right set clear Mac. Can you understand that three? I got it. I won't add anything.

It would be more foolish than usual for me to add anything else. But yes, I did get it. Thanks. I feel like you're the one who's sick, and I'm the one who's incoherent. But I guess that's no different than usual. Don't make me laugh. Please carry on to this week in space [00:38:00] history. It was 1969 this week that we had the first docking of two spacecraft that actually both had humans on board so used for and so use five and now on to random space.

I wish I could have said that I wish I was capable of thinking something like that. I was trying. Put the put the energy and it for you, maybe it'll transfer. This one's kind of obvious. But I mention it in case people haven't thought of it if you're on the surface of the Moon then your day night cycle is about 29 and a half Earth days long, so you've got day for a little over two weeks.

Earth weeks and night for over two weeks. And so if you're a spacecraft on the surface like the reach recently landed changa for. You experienced about two weeks of daylight and two weeks of night, which plays havoc with thermal [00:39:00] control because the surface of the Moon will change hundreds of degrees no matter what your temperature system pretty much.

Do you think there's anybody left in our audience more broadly? I'm sure there is who still thinks of where Chong you for as as the Dark Side of the Moon? Well, it depends on how you answer that in terms of as opposed to The Far Side. No, I hope not but it is for example when we're recording it the dark side right now.

It just changes from the Dark Side to the light side. So it's it's a chilling hard and lunar night. So it's the temporary. Side, so you're saying that within a few hours, I'll be living on the dark side of the earth. Exactly. It does exist. We move on to the trivia contest. This was the fun one for me because I don't think I ever have asked a question that we didn't know the answer to when I asked it, but now we know the answer I asked his 2014 mu [00:40:00] 69 nicknamed Ultima Thule.

The New Horizons flew by between when we ask this when we answer this. Is it a binary two objects a contact binary two lobes or none of the above. How do we do man? This was really fun. I mean you remember how thrilled I was when you pose this question two weeks ago the audience felt the same way at least the very large group of people who entered this time had a great time and we had people who are.

Just chomping at the bit waiting for Alan Stern and his team to flash that image up on a screen so they could enter the contest. I'm glad I made the flyby exciting because otherwise it would have been boring. I'm kidding that was sarcasm here. I know you are. Here's our winner Josh White. I know he's right because I was there Josh White in Sweetwater Tennessee as far as I know a first-time winner, he says, Ultimate Uli 2014 mu 69 if you prefer is a contact [00:41:00] binary.

That is correct. We see it as the contact binary otherwise known as a snowman. Yeah, two lobes. Congratulations Josh you have one this one you are on top of it a question that could not be answered until about a week and a half ago less than a week and a half ago. We are going to send Josh. A set of those really fun terrific kick asteroid stickers.

They're all five a complete set from Chop Shop Store Chop Shop is where you can check them out co-designed. Is that fair to say by Bruce Betts? Yes, maybe taking a little too much credit. I did none of the art. So don't worry. I just assess the scientific validity in an iterative process you consulted on their design.

There you go that's impressive. Okay, and a 200 point I telescope dotnet astronomy account for that worldwide network of telescopes and I do have others of [00:42:00] course Paul Brewer. Gel in Brooklyn New York. He says New Year's Eve was cool and all but the real countdown was at 12:33 a.m. On January 1st.

That's if you're in the Eastern Time Zone, he says happy full year. No, I get it now Steve White Nell in Antelope. Near another guy we've heard from before he proposes the a new name for this asteroid Altima Frosty and you know why it's because so many people including Alan Stern compared it to a snowman but it has been compared to other things and they were kind of all rounded up by Jonathan Aguilar in Baltimore, Maryland, very close to where I was its shape has been compared variously to sure A Snowman Star Wars bb-8 that little draw.

Kenny from South Park and an odd peanut he says to me though. It reminds me most of my 11 month old daughter Vera back when she was still small enough to be swaddled and quite [00:43:00] pink or this is from Bob clean in Chandler, Arizona. Would you and Bruce consider yourselves to be a contact binary when you're shaking hands?

Yes. I also fight about. Zero and who's the one if we're really binary but nah, we definitely know who the bigger lobe is. Yeah, Dave Fairchild our Poet Laureate will close it out mu 69 we've seen has bodies tied together and like we saw with feel a lobes are closer than a brother were two for two in visiting these solar kissing cousins with billions more to find that we can add to the discussion.

All right, we're ready to go on for next time what 180? Diameter crater to China for Landon and who is the crater named after go to planetary dot org slash radio contest you've got [00:44:00] until the 23rd January 23rd Wednesday at 8:00 a.m. Pacific time to respond and we will have for you will give you another set of those stickers the kick asteroid stickers from Chop Shop.

We will also give you 200 point. I telescope dotnet account. I found the. Hey, and I really had forgotten that I had this yet another signed copy of chasing New Horizons inside the Epic first mission to Pluto by Alan Stern and David grinspoon. It's an excellent book. I use some of you will remember that I talked with both of the author's some months ago.

Well before the flyby of this latest object and as I said, this one is signed by Alan Stern himself, so I get in on it and a little preview. I've been hinting. Now it can be told not this week, but in next week's contest the return. Of the rubber asteroid. Yay. I know long overdue. [00:45:00] We're done.

You've done a masterful job. Matt working through the your sickness. So everyone go out there. Look up the night sky, I think about Matt's health and your own and how to improve them. Thank you and good night. I'm going downstairs now to have some hot tea Bruce is the chief scientist of the planetary society and he joins us every week Here For What?

Planetary radio is produced via the planetary Society in Pasadena, California and is made possible by his high-flying members. Marylou's Bender is our associate producer Josh soil compost our theme which was arranged and performed by Peter Schlosser. I'm at

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