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Interviewer: Benjamin Thompson
Welcome back to the Nature Podcast. This week: examining the geology of exoplanets.
Interviewer: Adam Levy
Plus, a new fossil finding reveals a duck-like dual-terrain dino. This is the Nature Podcastfor December the 7th 2017. I’m Adam Levy.
Interviewer: Benjamin Thompson
And I’m Benjamin Thompson
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Interviewer: Benjamin Thompson
A Naturepaper is coming out this week that describes a new dinosaur called Halszkaraptor escuilliei which has some features that might be considered a little odd. This fossil had a rather interesting life, or perhaps that should be a rather interesting life after death. Initially these bones were poached from Mongolia and kept in private collections before being transferred to the Royal Belgian Institute of Natural Sciences in 2015. This is where the find is currently being studied before it’s finally returned to Mongolia in the future. The fossil is believed to be over 71 million years old which makes it from the late cretaceous period. However, because it wasn’t excavated properly or officially, the exact location of where this dinosaur was found is unknown.
Interviewee: Andrea Cau
We suspect that it lived in an environment that it is probably a semi-arid environment with other kinds of dinosaurs, for example the famous velociraptor is from the same locality.
Interviewer: Benjamin Thompson
This is Andre Cau from the University of Bologna in Italy who’s led the new research on this dino. Halszkaraptor escuilliei is a member of a group called the maniraptora. Among the maniraptora are lots of sub-groups of bird-like dinosaurs including the velociraptor as well as birds themselves. According to Andrea, maniraptor and dinosaurs look a bit different to the classic dino that you may have seen in a certain Hollywood movie.
Interviewee: Andrea Cau
We know that they were completely feathered so they were very bird-like in their physical appearance. Halszkaraptor is unexpected because it combines features from different groups of maniraptors and this is one of the reasons we decided to use a novel analysis for interpreting these fossils.
Interviewer: Benjamin Thompson
This novel analysis required some incredibly powerful X-rays, because carefully piecing together a skeleton from its individual bones wasn’t an option and this was due to the minor inconvenience of the fossil being mostly encased in a block of orangey-red sandstone. While making most of the fossil inaccessible, this sedimentary slab did afford the team an unspoiled view of the past.
Interviewee: Andrea Cau
This is typical of the fossils from this locality. They are exquisitely preserved because they probably died during sandstorms that preserved them perfectly – the bodies. And most of the skeleton is still preserved in the natural and the original position of the bones and we suspect that a few bones were eventually damaged during the excavation of the fossils but other bones not visible to us are still inside the sandstone block. They were digitally extracted using the synchrotron scanning.
Interviewer: Benjamin Thompson
The team used a synchrotron in the French city of Grenoble to bombard the sample with X-rays billions of times brighter than those used in hospitals. These rays pierced the sandstone and allowed the team to create a 3D reconstruction of the dinosaur skeleton. To me, the 2D version in the paper looks something like an ostrich with an extended tail. It’s got two long legs and a rather elongated neck that’s held vertically. What I didn’t take into account was the scale bar and rather than resembling an ostrich, Halszkaraptor is actually about the size of a big duck. Turns out though that I was kind of on the right track thinking about birds because Halszkaraptor had a number of avian like featurwes, as Andrea explains.
Interviewee: Andrea Cau
The head is similar to a bird – it’s quite duck like – and even the neck is similar to a swan but no other kinds of dinosaurs showed this particular neck. Another unexpected feature is the strange proportions in the front limbs and when we searched here amongst living animals and fossil animals, those with the similar proportions, we found that in aquatic animals we see similar proportions.
Interviewer: Benjamin Thompson
Because of these features, the researchers hypothesized that Halszkaraptor is a new kind of semi-aquatic dinosaur. They suggest it would have walked about on land on its back limbs but used its flipper like fore-limbs to move about on water. Its elongated, swan-like neck could have helped it forage for food or catch fish. Andrea told me that dinosaurs weren’t generally very successful at adapting to marine environments and there are very few examples of semi-aquatic species. This makes this new finding rather special.
Interviewee: Andrea Cau
We have other dinosaurs that were decided to be semi-aquatic but the reconstructions of these dinosaurs are usually considered more crocodile-like, swimming-styles. This is the first time we have a dinosaur that may have used its front fins during swimming.
Interviewer: Benjamin Thompson
While this dual terrain dino is an interesting find, more fossils need to be unearthed to give us a better idea of how Halszkaraptor moved, whether it swam like any modern birds and where it fits on the evolutionary tree. In the mean time, the mere fact that this fossil has been found is quite exciting enough in itself for Andrea.
Interviewee: Andrea Cau
I was completely shocked the first time I saw this fossil because it’s completely unexpected but at the same time it’s from an area well known in dinosaur paleontology and we usually assume that the most unexpected dinosaurs will be discovered in areas like Antarctica or South Africa that have not been particularly excavated. The discovery of this completely unexpected dinosaur in Mongolia is unexpected itself because we expected to have found all groups of dinosaurs from Mongolia.
Interviewer: Benjamin Thompson
That was Andrea Cau there. You can read his paper over at nature.com/nature. If you’re curious what life is like in the synchrotron where the team scanned their dino, head over to youtube.com/NatureVideoChannel. Our short film, ‘24 hours in a synchrotron’ shows how intense research life can be in a science facility that never sleeps.
Interviewer: Adam Levy
The News Chat is still to come where we’ll be learning about a deep space space-station and the origins of SARS. First up though, Noah Baker is here and he’s armed with the Hesearch Highlights…
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Interviewer: Noah Baker
Who would win this arm wrestle… the world’s greatest women rowers or the first female farmers? Well, a study comparing their arm and leg bones suggests that early agriculturalists would have the upper hand. Even though the prehistoric bones were more like those of semi-elite rowers than runners, the ancient women had much stronger arms. This is probably because the daily grain grind and soil tilling was done by hand before beasts of bird and cultivation contrivances made farming a right doddle. Leg it over to Science Advancesfor the full paper.
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Interviewer: Noah Baker
And now, the latest contender for the mightiest muscles: a robot with an origami skeleton. Engineers have flexed their minds and assembled an artificial muscle that out-performs its human counterparts. They folded a metal or plastic structure into a consatina and put it inside a stretchy skin. The skin could be filled with air or water. Sucking out the fluid forces the skeleton to collapse and contract, generating a pulling power several times that of a human muscle of the same weight. By changing the origami folding pattern the team made muscles that could squeeze, bend and twist and used their dexterous device to lift a twenty-two kilogram car wheel. The simple design could inspire tiny surgical tools or enormous robotic arms on space stations where neither athletes or farmers would be very appropriate. Get to grips with this weighty research over at PNAS.
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Interviewer: Adam Levy
Just how unique is our planet? Earth glistens with water, is home to continents, and its magnetic field protects its surface from harmful solar winds. These factors and many others mean that earth can support life. Nothing else orbiting our sun resembles our green-blue planet and, until a couiple of decades ago, that was the end of the story. The idea that there might be other planets out there, some of which might resemble earth, was sheer speculation. Then, in the 90s, all that changed. Astronomers learned to spot planets orbiting other stars. Sometimes they’d spot a star’s brightness dim as a planet passed in front. Sometimes they’d see a star wobble ever so slightly as it was tugged by a planet’s gravitational pull. Today, thousands of these exoplanets have been discovered which begs the question, are any of them anything like earth? But these planets are lightyears away, meaning we have limited information to go on.
Interviewee: Cayman Unterborn
When we think about exoplanets we kind of have to think about very few observables: mass, radius, something about its orbit and maybe down the line something about its atmosphere and that’s it.
Interviewer: Adam Levy
This is Cayman Unterborn. He’s an exoplanet geologist.
Interviewee: Cayman Unterborn
So with those four parameters I have to build a planet and kind of understand everything going on.
Interviewer: Adam Levy
Understanding exoplanets could teach us which ones are more like earth and this would provide clues in the ultimate quest to find life on other worlds. Finding candidates for worlds that could support life requires astronomers to first observe whether an exoplanet is in its star’s so-called habitable zone, where the distance is just right for the planet to be able to support liquid water. But…
Interviewee: Cayman Unterborn
This habitable zone concept is great for a first cut. Is that planet in its habitable zone? Yes. It’s likely to have liquid water but there’s a lot more steps after that that say, well okay, is it too much water? Well, can it produce continents that are of the right composition to aid in these geochemical cycles? What’s its likelihood of it having magnetic fields? These are all secondary things that the more that planet has in it’s favour, the more the geologist in me would be comfortable to say yeah, go ahead an invest a year’s worth of observations and really dig in.
Interviewer: Adam Levy
If there’s one thing that our observations have taught us so far it’s the sheer diversity of planets in our universe. Researchers can’t just assume that planets orbiting other stars formed in the same way as in our solar system, that’s according to Rick Carlson who generally works on what our sun’s planets made of.
Interviewee: Rick Carlson
You know, we’ve opened our eyes now to the fact that there are many possibilities… We’ve only got four terrestrial planets in our solar system. We’ve got 400 million of them – that’s a guess not a firm number – but some very large number of terrestrial planets, we’ll call them, in other solar systems, and they’re just going to provide us with an eye opening look at the diversity of geological processes that can happen on planets.
Interviewer: Adam Levy
Astronomers are cataloguing more and more exoplantes, each with their own unique conditions and so researchers are going back to the drawing board to find out how different conditions could impact an exoplanet’s geology. For example, astronomers have observed stars with ratios of magnesium and silicon radically different to those in their own sun. To find out what this could mean for alien rocks, geologists have to synthesise similar minerals and see how they respond to extreme conditions.
Interviewee: Cayman Unterborn
We can kind of make guesses on what that might look like but it would be really great to put it in an experiment, bring it up to pressures and temperatures that are characteristic of what that planet will have and see actually what it looks like so we can better formulate our models. If we want to understand whether a planet is habitable or even remotely earth-like, we really need to model a lot of these geologies.
Interviewer: Adam Levy
The more information astronomers can get hold of, the more geologists like Cayman hope to deduce about an exoplanet. Watching starlight shine through an exoplanet’s atmosphere, for example, may tell us what gases that atmosphere contains, and Rick explains that this could, in turn, reveal all sorts of secrets.
Interviewee: Rick Carlson
Information that we could get could tell us about, for example, life which is of course one of the big goals in this but also tell us about volcanism on the planet. It could tell us whether there’s liquid water present on the planet, so it will be a very big extrapolation, to take an atmospheric composition and deduce the geological evolution of the planet, but it’s not impossible.
Interviewer: Adam Levy
Considering just how little raw information we have about exoplanets, geologists like Cayman and Rick remain optimistic about what we may be able to learn. Cayman, for example, suggests that we may one day spot a planet with continents by seeing starlight gleam off the surface in wavering patterns. It’s been little over twenty years since the first exoplanet was discovered. In that time, astronomers have added more and more to the list. And now, geologists are helping unearth as many secrets as they can about these distant worlds.
Interviewee: Cayman Unterborn
It’s the geophysicists and geochemists who are gong to provide the broadest context of what that planet has going on. When the paper comes out in Naturethat we have found a habitable exoplanet and these are the bio-signatures, it hopefully will have been vetted by quite a few geophysicists before that paper comes out.
Interviewee: Rick Carlson
I think there have been few times in human history where just our view of our place in nature has changed so dramatically and it’s just a great time to be in the field. It’s just thrilling to me. I’m obviously biased but I do find it a thrilling time to be in the field.
Interviewer: Adam Levy
That was Rick Carlson of the Carnegie Institution for Science in DC, and Cayman Unterborn who's at Arizona State University. To find out more about exoplanet geology, make sure to read the feature in this week's Nature. Find it at nature.com/news.
Interviewer: Benjamin Thompson
Now it’s time for this week’s News Chat, and I’m joined in the studio by Lizzie Gibney, Senior Reporter here at Nature. Hi Lizzie.
Interviewee: Lizzie Gibney
Hello.
Interviewer: Benjamin Thompson
We’ve just heard Adam talking about space there and obviously we love stories about space so it’s time for another one. Lizzie, what’s going on?
Interviewee: Lizzie Gibney
Well, so this is something called the Deep Space Gateway. It’s currently just a plan. The world space agencies – so we’re talking NASA, ESA, JAXA – they all have this idea for what they want some time in the 2020s as a space station to replace the International Space Station which is currently orbiting around earth but this time it would be in the vicinity of the moon. So it would probably be orbiting in a very elongated funny orbit around the moon and it would be somewhere you could actually send humans to and this is an exciting idea. It’s not one that has yet been funded but there’s a lot of momentum building behind it and what’s happening this week is that scientists are getting together to try and come up with ideas for the kind of science that you would do on that kind of spaceship.
Interviewer: Benjamin Thompson
So this is very much then on paper at the moment?
Interviewee: Lizzie Gibney
It is, exactly. It’s the very early stages but if we want to have a space station that not only fulfuills all the objectives that the space agencies want which are things like being a place for space diplomacy and really, the most important one, is to promote human exploration in space… So, to figure out how to live in deep space, how to survive for a long time as a kind of stepping stone for eventually going further, perhaps to Mars. But if we also want it to do some really good science which you do given that it’s going to cost a huge amount of money and it’s a really unique place to have a laboratory, then you want to get in at the early stages as well to try to figure out even how best to design this space station so that it fits your science goals as well as your exploration ones.
Interviewer: Benjamin Thompson
So when you say space diplomacy then, do you mean that this is agencies from all over the world coming together?
Interviewee: Lizzie Gibney
Exactly, if you think back to the space race, that was really militaristic and that was about a rivalry between the USSR and the US. Today what they’re trying to do is follow on from the International Space Station which was really healing those Cold War wounds and now going even further and saying can we get everybody on the planet, every space agency to come up with a single plan and to explore space together? There is one conspicuous absence from that list which was China. I don’t know if China are at some point going to want to get involved because they certainly have big ambitions in space as well.
Interviewer: Benjamin Thompson
So, speaking of ambitions there, what can this new Space Station do that the ISS can’t?
Interviewee: Lizzie Gibney
Well the main thing is about its location. So, it will be far away from earth and earth has this protective magnetosphere and also an ionosphere of charged particles and that means that the environment much closer to the moon will be very representative of deep space so it’s going to be the best kind of way to mimic the environment that humans will have to face if they then end up going on very long duration journeys out to places like Mars. It’s also going to be really close to the moon – a great vantage point because you can potentially, say, operate rovers from this space station and you can do that even when your rovers are on the dark side of the moon which is where it’s particularly interesting because that’s where the ice is on the moon. And also you could maybe collect samples and then just bring them back to the space station laboratory and you wouldn’t need to then take them all the way back to earth and that way you could get greater diversity of samples, you could get more mass. It’s got this really unique location.
Interviewer: Benjamin Thompson
I mean, all seems pretty well then in our future ‘space-utopia’ but realistically, what are people hoping it’s going to do, or are they still assuming it’s going to do everything?
Interviewee: Lizzie Gibney
Well they’re going to have to whittle this down, I guess, quite a lot. Probably what’ll happen is it’ll be a bit like the ISS, the International Space Station, in that there will be a host of proposals and they will pick from the best ones. What we hope really is that considerations about the kinds of science that they do on this Deep Space Gateway will help shape the actual structure itself. So, for instance, how many observatories, telescopes, could you stick on the outside of it? What kind of orbit can it have? Can it move between orbits? That’s the kind of thing that you might want to do if you want to make different kinds of observations, so I think it’s going to be very hard in the near future to actually come up with a concrete list of things that you’d want to use it to study given that what we’re talking about is the 2020s, perhaps going into the late 2020s. But you want to make sure that science is in there from the start.
Interviewer: Benjamin Thompson
Alright then. Well, changing tack we’ve got a story about SARS as well. What can you tell us about that?
Interviewee: Lizzie Gibney
Well, so if you cast your mind back to 2002 we had the SARS outbreak. It’s a respiratory disease, it infected thousands of people, killed almost 800 and it’s been a bit of a mystery as to where it actually came from originally. So, scientists at the time sequenced the genetic strain of the disease to try and figure out exactly where it may have originated and they found a few leads, one of them being that they found a similar strain in some civets in China. They’re kind of cat like mammals and also in these bats called horseshoe bats. But there’s a little bit of a puzzle because one of the particular proteins that were found in the human strain that proved so deadly wasn’t actually in these varieties that they found. So, scientists in China have been trying to track down, with some very clever detective work, exactly where this strain may have come from.
Interviewer: Benjamin Thompson
So yes, it’s an interesting one. I think the first believed culprit was these civets in food markets, right? So SARS is a zoonotic disease that goes from animals to people and so they’ve been following it back around to a location where the bats live presumably.
Interviewee: Lizzie Gibney
So, they tracked bats to many different cave locations across the country and there was one cave in particular where they found lots of strains that had similarities to this human version of SARS and they spent five years analyzing the guano and sequencing all these different strains and what they found was not exactly the same strain as was found in humans but several different strains that when you put them together, did give you these human strains. So all the building blocks that look very likely to have come together at some point to transmit into civets and then humans.
Interviewer: Benjamin Thompson
Bats are super interesting then for a lot of zoonotic virusal diseases, things like Nipah and maybe even Ebola as well, and they act as these kinds of reservoirs where the virus lives when it’s not in a human host. In this case we’ve talked about individual parts of SARS being in individual bats – is there concern that this can recombine again in future?
Interviewee: Lizzie Gibney
Well that’s the thing… genetic mixing among these different viral starins happens very fast and in this case the cave where we think SARS emerged is just a kilometre from where people live in a village so it does seem that this kind of spill over could in future happen again.
Interviewer: Benjamin Thompson
Yeah, and I think that spill over was an important word there. I think I read somewhere that 60% of human viral diseases are zoonotic in their origins and given that SARS came out of nowhere in 2002 essentially, knowing more about these things and where these spill overs may occur seems super important.
Interviewee: Lizzie Gibney
It is very important and that’s why theyr’re doing this kind of work. The other message that the researchers actually give is that we should really try and leave wildlife in their habitats. The problem here, they think, arose from putting wild animals into the markets so that’s something else that we should perhaps take away from it.
Interviewer: Benjamin Thompson
And that’s something then that’s maybe slightly puzzling. The actual population of these bats is a very, very long way away from where the outbreak of SARS occurred.
Interviewee: Lizzie Gibney
That’s right. So it’s the Guangdong region where this outbreak occurred but the bats are in Yunnan which is about a thousand kilometres away and the researchers haven’t found any intermediary cases. So that part remains a little bit of a puzzle.
Interviewer: Benjamin Thompson
Thanks Lizzie. For more on those two news stories, head over to nature.com/news.
Interviewer: Adam Levy
That’s it for this week. Don’t forget to follow the show on Twitter; we’re @NaturePodcast and you can email any feedback to us on podcast@nature.com. I’m Adam Levy.
Interviewer: Benjamin Thompson
And I’m Benjamin Thompson. Thanks for listening everyone.
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