Planetary Radio: Space Exploration, Astronomy and Science - Oceanographer John Delaney Jumps in Europa's Ocean

Episode Date: March 27, 2006

Oceanographer John Delaney believes our growing knowledge of Earth's oceans will help us explore the sea under Europa's ice.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

An oceanographer dives into the seas of Europa, this week on Planetary Radio. Hi everyone, welcome to Public Radio's travel show that takes you to the final frontier. I'm Matt Kaplan. Even as he leads revolutionary research on Earth's oceans, I'm Matt Kaplan. That mysterious moon of Jupiter also floats to the surface in this week's particularly wacky What's Up segment with Bruce Betts. With not a moment to spare, let's review the week's top space headlines. The very first pictures have been returned by the Mars Reconnaissance Orbiter. The test shots are already as good as any yet taken from orbit, with much better images yet to come as MRO settles into a far lower orbit.

Meanwhile, down below on the sands of the red planet, little Spirit continues to limp toward a small hill that may enable it to survive another Martian winter. If it makes it, the incline will help the rover's solar panels gather the needed energy. A broken wheel motor isn't helping any. A bit of sad news that we're late in getting out. We told you several weeks ago that one more attempt would be made by the Deep Space Network to contact faraway Pioneer 10. Well, we called, but no one answered. Pioneer Anomaly team member Slava Turashev has additional details in his report at planetary.org.

Comets, asteroids, solar system is full of them. But what's the difference? That's the Q addressed by Emily this week. I'll be right back with John Delaney. Hi, I'm Emily Lakdawalla with questions and answers. A listener asked, what is the difference between a comet and an asteroid? Before the space age, this was a trivial question to answer. Viewed through a telescope, both comets and asteroids move against the background of more distant stars,

indicating that they reside within our solar system. Asteroids are tiny points of light, mostly unresolvable as disks, unlike planets, and most have orbits that lie between those of Mars and Jupiter, though there are exceptions. Comets, on the other hand, look fuzzy, surrounded by a light-scattering coma of ice and dust particles. As they approach the sun, they get fuzzier and may develop long tails. They mostly have orbits that are extremely elongated, indicating that most come from the outer solar system from a theorized region called the Oort cloud. So there seem to be two clear classes.

Asteroids formed in the inner solar system and are made of rock and metal, and comets formed in the outer solar system and are made of ice. But the story isn't so simple anymore. Stay tuned to Planetary Radio to find out why. We first heard from oceanographer John Delaney three weeks ago on our special coverage of the Europa event at NASA's Ames Research Center. Before he took the stage that

day, the distinguished University of Washington oceanographer and undersea explorer, talked with us about why he's so excited about what we are learning about Earth's oceans and his belief that this knowledge will help us understand a sea that is half a billion miles away. What can the oceans of Earth and what we are learning about them tell us about the oceans that we strongly suspect are hiding there under the ice on Europa. Well, that's an excellent question. And, of course, many of us on both sides of the fence, the space side and the ocean side, ask that question. And I guess the underlying perspective actually originally discussed by Steve Squires way back when the Voyager mission was flying by was the possibility that the discoveries on the seafloor at about that time of submarine hydrothermal systems

are potential analogs for what might actually be going on on the seafloor of a Europan ocean. At the bottom of whatever the layer, the density one layer is, probably water, almost certainly water at the surface, and probably water most of the 100 kilometers that are estimated, is liable to be liquid. It's liable to be, have a salinity of some sort, that is, dissolve salts. And it's liable to be driven now or was once driven by the thermal heat transfer from the underlying rocks to the overlying ocean. What the intensity of that exchange is, both chemically and physically, thermally, is a great question.

That is probably one of the great questions in planetary sciences within our solar system, I think. Is there another planet where processes similar to what may have happened on Earth have taken place? Could there be life that evolved either separately or was salted by some other mechanism on Europa as well as on Earth and maybe other places, but some of the planets have been excellent incubators for whatever life may have either developed or landed. Others have obviously been less so. Our moon would probably be a harsh environment. A harsh mistress, as someone once said. So that leaves us in a very exciting position of saying, well, okay,

So that leaves us in a very exciting position of saying, well, okay, a large fraction of the seafloor here is dominated by the largest volcanic system on our entire planet, the Mid-Ocean Ridge System. It's about 70,000 kilometers long, and it spreads around the world like strings on a baseball. And it's continuously spreading apart at about the speed your fingernails grow. And what's moving into the potential voids is molten rock. It comes to the surface in a few places in Iceland where we can actually see the volcanic eruptions, but we know from visiting it with submarines like Alvin,

anywhere from 2,000 to 4,000 meters below sea level, that it is volcanically active. There are very vigorous submarine hydrothermal systems that have been found in every ocean, Indian, the Pacific, a lot in the Pacific, and the Atlantic now. So the question then is, are these meaningful analogs to what kinds of systems might be on the floor of the Europan Ocean? to what kinds of systems might be on the floor of the Europan Ocean, and if so, what are the mechanisms of research or the approaches to research that we can bring to bear on our own ocean volcano system

that might illuminate some of the questions that are being asked about Europa. There is a lot of focus on Lake Vladivostok and the idea of getting through the ice as being kind of the big event. I'm an oceanographer, so I tend to think of the big event as once you're through the ice, what do you do? And that makes me smile, and I love to imagine what it would be like. Now, we should explain this lake, Lake Vladivostok, or Lake Vostok, I've heard it called. Oh, sorry, you're right, you're right. Vostok is right.

I misspoke. Sorry. Thank you. But it is a lake that has a layer of ice, and we have very good evidence that there is liquid water beneath the surface. And so this would seem to be a pretty good place to go and take a look and see how things work. That's true in terms of getting through the ice. In other words, if you're trying to break into the bank, Lake Vostok is a good place to try your craft.

If, however, what you're trying to look at is what kind of submarine hydrothermal systems might be associated with active underwater volcanoes, it may be far less of, in other words, the right kind of gold may not be in that bank. But learning how to break into banks is a good thing to do if you're looking for life on other planets. We still have so much more to learn about how the ocean works on this planet. Are we anywhere near the point where we could model it in a place like Europa? near the point where we could model it in a place like Europa? I suspect that it would be possible to develop a suite of models that would not be in any way testable for a number of years.

But they may guide the kind of exploration programs we might put together. And I think it would probably be a very valuable effort to have a group of very bright modelers and observationalists and geochemists and at least microbiologists thinking carefully about what the circulation patterns of the Europan Ocean might be, because therein lies a big piece of whatever the tail will be when we get through the ice. There are first principles, that is, if the ocean is heated from below and it's cooled from the top, then it's going to turn over. If it turns over rapidly enough, then it's not going to be very stratified. In other words, it won't have strong layering of different densities.

But that's an open question, and that's a very controversial issue about the dynamics of what the Europan Ocean might be. There may be other factors that are involved in the patterns of circulation. It's possible that the Coriolis effect enters into the global circulation of the Europan Ocean, and it's possible that it actually enters into rising plumes that may be coming off of erupting underwater volcanoes. There are an entire host of possible model components that I think could be put together by the right folks, of which I am not one. But you certainly are a contributor, and this is something that we talked about before we began recording, and that is that up to this time,

the relative isolation of these two communities, oceanographers who look quite logically at the oceans of the Earth and tend to ignore things beyond our planet, and planetary scientists who are not oceanographers but are very curious about Europa. That's true, and I've spent a lot of time thinking about why those two groups spend so little time talking to one another. I think that's slowly changing, but for sure, for a long time,

planetary scientists dealt with Europa as if it was an ice planet and tried to interpret much that they saw on the basis of ice dynamics, and that still works very, very well. Bob Pappalardo is one of the leaders in that area in terms of interpreting surface features. However, if there is an ocean that is anywhere from tens to as much as 100 kilometers deep on that planet, that's a very, very large body of water, and it is incumbent on us to begin thinking deeply about how it must circulate.

Planetary Radio will return with more from oceanographer John Delaney in just a minute. This is Buzz Aldrin. When I walked on the moon, I knew it was just the beginning of humankind's great adventure in the solar system. That's why I'm a member of the Planetary Society, the world's largest space interest group.

The Planetary Society is helping to explore Mars. We're tracking near-Earth asteroids and comets. We sponsor the search for life on other worlds, and we're building the first-ever solar sail. We didn't just build it. We attempted to put that first solar sail in orbit, and we're going to try again. You can read about all our exciting projects and get the latest space exploration news in depth

at the Society's exciting and informative website, planetary.org. You can also preview our full-color magazine, The Planetary Report. It's just one of our many member benefits. Want to learn more? Call us at 1-877-PLANETS. That's toll-free, 1-877-PLANETS. That's toll-free, 1-877-752-6387. The Planetary Society, exploring new worlds. Welcome back to Planetary Radio. Our guest this week is renowned oceanographer John Delaney. Before the break, John talked about the interest in oceanography only very

recently developed by some planetary scientists studying Jupiter's moon Europa. But what about his colleagues that study the seas of Earth? I can explain why the oceanographers don't get too interested in Europa. Most of them are focused on two- to four-year grants that have a cycle time that requires them to go to sea on a regular basis and ships or use satellite data. And they tend to think of Europa as, if you'll forgive me in terms of the financial side, pie in the sky, if you like, and a long ways out and not something that is going to help them raise funds for the next grant cycle, which is probably correct.

But you are an oceanographer who has crossed that line. Yes, but I'm an inveterate dreamer, and so I think it's really cool that there might be, and all of my colleagues think it's cool. They just don't spend very much time, you know, just plain dreaming about it. But frankly, I think one of the things that drives me is the question of, are there comprehensive programs that could be put in motion here on Earth to shed additional light on what kinds of systems might exist on Europa. And one of those clearly is somehow gaining access through the carapace of ice over Vostok.

Another might be a comprehensive program to study the entire ecogenomic suite of microbes that is actually occupying the rocks below the sea floor. You may not be aware, and maybe your listeners aren't aware, that the very famous underwater hydrothermal systems where everybody has seen the lovely bright red tube worms waving in the breeze, that's very fascinating, but it's actually only the tip of the iceberg. There is a vast microbial biosphere that lives below the seafloor in the pores and the cracks of the rocks. And we have found that in 11 out of 11 cases where we've chased underwater volcanic eruptions,

in every single case there's been massive effusion of microbial material and microbes. High-temperature archaea, a very ancient hyperthermophilic, that is a very extremely high-temperature loving microbes, have issued from below the seafloor in waters that are only 10 to 20 degrees centigrade. But many of these don't reproduce until they're at temperatures close to 60, 70, 80 degrees centigrade. So we know they come from hotter places below the seafloor. And in every single case, this massive effusion takes place. And so we conclude that there is a major biosphere that we know very little about. We don't know much about its nutritional

framework. We don't know what the major events are in changing such things. But somehow, it's fascinating to me, somehow it's tied to plate tectonics. When big earthquakes take place, we see these things. When volcanoes erupt, we see them. We see these microbial blooms coming out of the seafloor. So is there a similar type of dynamic going on on the floor of the ocean of Europa? That's an open question. dynamic going on on the floor of the ocean of Europa?

That's an open question. With only a couple of minutes left, we need to talk about yet another thing that might be done here on this planet. You have been working on this for years, and that is to build a network that would be able to monitor our oceans at the genomic level and many others, that would operate essentially without human hands. Yes, and I'm very, very excited about that. To talk to a planetary society group about it is a little unfortunate because we named it using the terms Northeast Pacific Time Series Undersea Networked Experiments, which translates to Neptune.

But it will be a major attempt to lay about 3,000 kilometers of fiber optic cable in a network across the Juan de Fuca Plate, giving access to the seafloor via an extension of the Internet to the seafloor. It's been decided by a community of oceanographers that that's the place for the first of these regional cabled observatories, which is the term that the National Science Foundation uses. I must say that it's part of a bigger program

which will result in global moorings that will be distributed around the planet and a focused effort on coastal environments. And the regional cabled observatory is sort of the mesoscale of this ocean-observing system. However, the technologies that will be developed using robotic remote-sensing platforms that will be autonomous as well as deployable via the fiber-optic cable with communications at the speed of light, two-way turnaround time gives you command control over anything that's in the water in this network. It will also give us moorings that are up in the water column

and meteorological stations that are right at the sea surface. So all of this information comes back via the cable to a central location and is distributed in virtual real time, we hope, to people, anyone who has access to the Internet. So this is a big step. We will be basically running seafloor rovers, if you like, that will be up in the water on the seafloor. Some of them will be down in drill holes. We'll be looking at everything from the dynamics of earthquake activity to the microbial responses to big storms to blue whales migrating

to fish stock evolution to phytoplankton. It just goes on and on and on. Even to the point of sequencing genomic material that these autonomous robotic explorers find in the ocean. That's the intent. So this is very, very exciting. This is going to revolutionize oceanography on this planet. And the hope is 10 to 20 years from now,

we will be able to export much of what we have learned in this robotic, remote-sensing, in-situ, scientific approach that we will be taking into how our own ocean works. And I hope some of that will flow over into a Europa program, which I am desperately hoping will happen before I die. As are we all listening to this program, I'm sure. John, we're out of time. Thank you so much for joining us. I know in a few minutes you're going to be inside sharing some of maybe similar remarks with the public as they show up for this

Europa event at the Ames Research Center near San Jose, California. Well, I hope I won't make the same mistake and call it Lake Vladivostok. I'm willing to bet you won't. I've clearly been out of the business for a while. Dr. John Delaney is a professor of oceanography at the University of Washington, also leader of the Neptune Project, and someone whose interest in the oceans of Earth extends far beyond our home planet, perhaps to that mysterious body of water that lies just under the ice on the moon Europa.

We'll be right back with Bruce Betts in this week's edition of What's Up after this return visit from Emily. I'm Emily Lakdawalla, back with Q&A. The differences between comets and asteroids used to be obvious, but more and more bodies are being discovered that blur these sharp distinctions. First of all, as better and better telescopes are detecting tiny objects in more distant regions of the solar system, we're finding that there are lots of objects with orbits that are intermediate

between the types of orbits in the asteroid belt and the orbits of the shortest period comets. Secondly, we're getting better at determining both the surface compositions and the densities of tiny, point-like objects in our skies. And some things that we have always thought were rocky asteroids are turning out to look much more like the porous, lightweight, pitch-black cores of comets that we've visited with spacecraft like Giotto, Deep Space One, and Deep Impact. the solar system inhabited by the larger planets. A goodly proportion of these objects are actually the extinct cores of comets, whose surfaces have been baked and annealed by too many trips too close to the sun. And that's good news for the future of space exploration.

One day, these closer extinct comets may provide human explorers with a ready source of water waiting in space. Got a question about the universe? Send it to us at planetaryradio at planetary.org. And now here's Matt with more Planetary Radio. Time for What's Up on Planetary Radio. Bruce Betts is here. He's the director of projects for the Planetary Society.

He's going to tell us all about what's up in the night sky this week and bring us a special trivia contest, one that's even more entertaining than usual, I hope. We hope so. We're going to ask you to entertain us. Well, not you, Matt, but our listeners. We're going back to a humorous trivia contest. We'll get back to that in just a few moments.

Little tease. Little tease, yeah. So we'll talk about things in the night sky. In the meantime, I do need to mention, since some people will be hearing this before March 29th, last chance to see that solar eclipse that will be occurring. The umbral shadow will begin in Brazil, go across the Atlantic, northern Africa, central Asia, ending at sunset in Mongolia. Yes, that's right, sunset in Mongolia. Yes, that's right.

Sunset in Mongolia. That's where we will be. In my dreams. Isn't that a movie that you're putting together? Oh, yeah. Yeah. Yeah, we're casting now. Starring the sun as the sun.

Okay, that was silly. No more silliness. Yes. What do you mean no more silliness? More significantly, for lots of you, that there will be a partial eclipse. You will be able to see it throughout much of Africa, Europe, and Central Asia. For those of you like us who will not be seeing it, you can watch live webcasts of it, including from the very nice NASA eclipse site that you can find on the web.

For all those other things we've got in the night sky, let's talk about those fun planets. Let's start in the pre-dawn this time. We've got Venus looking extremely bright, brilliant, white, and spiffy before dawn. You can't miss it off in the east. And you can also see Jupiter off in the west looking less bright, but still really bright. But the neat thing is, for people like me who don't like to get up in the pre-dawn, Jupiter's coming on over to the evening sky. So you can see it by about 10 p.m. now up in the east looking extremely bright.

You can also see Mars hanging out kind of close to Aldebaran and Taurus. They're both kind of reddish. Aldebaran, a bright red giant. So different beasts looking kind of similar. And you can see Saturn in the evening sky. If you find Castor and Pollux, the two bright stars of Gemini. They're kind of pointing towards yellowish Saturn right now. So, let's move on. Turns out this week, absolutely nothing interesting happened in space history. No. Something happened. Come on.

Something interesting happened. Well, I'm sure something interesting happened, but I couldn't find what it was. Sure, there were little random miscellaneous launches here and there, but nothing that significant. So I'm sure if they're, you know, right now, someone out there is going to be highly offended by their great space accomplishment. If we ignore your accomplishments from this week sometime in the past, be sure and write to us, and we'll correct it next year. And those of you in charge of neat things in space, let's try to arrange some for this week, okay? Yeah, you've got a year. Yeah, exactly. We'll check back next year.

We'll evaluate it. This is not the trivia contest we referred to, but it is neat. Let's move on to random space facts. I love these new approaches. Thank you. Thank you very much. Europa, moon of Jupiter, on a large scale is extremely smooth. It's as smooth as a billiard ball if you could squish it down to that size, which would be tough.

But it is very rough, we know from looking at it in high-resolution images when you get to small scales. You've got lots of cracked ice and stuff, but the big features are only a few hundred meters to a couple of kilometers high. So conversely, he said, if we expanded a billiard ball to the size of Europa, it would look all rough and yicky. Well, that wasn't exactly what I was saying, but yeah, I suppose that's possible. The real issue is you'd end up having those little chalk marks. The blue chalk kind of would be huge.

Do billiard balls have liquid centers? No, I think they have chewy centers. Ooh, yum. Nougat. Kind of like Europa with the Tootsie Center. The candy Europa. Candy Europa. Yes, you bite through the crunchy ice shell to the lovely liquid water ocean

and then bite through to the candy nougat Tootsie Pop in the center. The surprise inside. The biologically active surprise inside. Oh, that sounds tasty. And then you can blow bubbles with it when you're done. All right, let's go on to our trivia contest. We asked you, who is the only man who has a feature named after him on Venus? All other features, of course, named after women, either real or mythological, and a couple of Greek letters.

So how did we do, and who is it? Matt, tell us, tell us, tell us. James Clerk Maxwell. Who'd have thought? James Clerk Maxwell got the honor of being the only guy-type person to have a spot on Venus named after him. We had a lot of weird guesses, a lot of strange guesses. Someone guessed Carl Sagan. I'm not sure where that came from.

He does have a feature named after him, but not on Venus. Not on Venus. Wrong planet. But it was Stephen Witte, a regular. Stephen Witte, who's quite witty, actually. And trying to make us laugh this time with some thermodynamics jokes and Einstein and James Clerk Maxwell. But we're not going to take the time to mention those. Thank you, Steve.

Thanks for trying. I will mention, for those unaware, James Clerk Maxwell of the famous, at least in the technical community, Maxwell equations, defining all of electrodynamics and things like that. Yeah, cool stuff, which I guess is how he got named. That's what Stephen says because of the radar they used. He made it all possible. But at any rate. Thanks to him, it works for all of us. Stephen, in Allen Park, Michigan,

we're going to send you an Explorer's Guide to Mars poster, and you watch for that in the mail, will you? All right, here's our new trivia contest. Here's what we've teased you about. That's right, make us laugh, entertain us this week. We're asking you about the new red spot on Jupiter. I kid you not, there is a new red spot that has been observed on Jupiter, a white spot going red, and it is smaller than the great red spot,

which is the official word for the Great Red Spot, which has been seen for hundreds of years on Jupiter. And now what? What should this new red spot be called? And of course, if you tell us, it will be officially named that forever and ever. Yeah, it has to be wacky, and then it will be recognized by what? The International Astronomical Union. I'm sure they'll go along with it. Or at least if it's funny, we'll mention it on the air. And you'll win a poster.

Exactly. And we'll mention a few runners-up as well. But you've got to make us laugh. Come on. Come on. This can't all be on our shoulders. How do they enter? They go to planetary.org slash radio and find out how to enter the contest.

Send us your answer. When do they need to get it in by, Matt? Why they have to get it to us by April 3rd, 2 p.m. Pacific time, April 3rd. And we look forward to seeing every single one of these. Well, or at least the funny ones. Yeah. Okay, thank you, everyone. Go out there, look up at the night sky,

and think about how important magnets have been in your life. Thank you, and good night. He's Bruce Betts. He's the director of projects for the Planetary Society. But you knew that. Well, yeah. He's here with us every week for What's Up. Thanks for joining us.

Planetary Radio is produced by the Planetary Society in Pasadena, California. Have a great week, everyone. Thank you.