00:00:00 --> 00:00:00 Professor Fred Watson: Hello again.
00:00:00 --> 00:00:03 Andrew Dunkley: Andrew Dunkley here from Space Nuts, where
00:00:03 --> 00:00:05 we talk astronomy and space science. Good to
00:00:05 --> 00:00:07 have your company. Coming up on this episode,
00:00:08 --> 00:00:10 we are, going to talk about the moon. It's
00:00:10 --> 00:00:12 got a near side, it's got a far side, but
00:00:12 --> 00:00:15 we're going to talk about the inside. it's,
00:00:15 --> 00:00:17 discovery of the Grail mission.
00:00:18 --> 00:00:20 which means what we're talking about is a
00:00:20 --> 00:00:23 flesh wound. another Hubble tension. Think
00:00:23 --> 00:00:26 about it. Another Hubble tension theory. And
00:00:26 --> 00:00:28 we're talking evolution this time. And a
00:00:28 --> 00:00:31 triple system in the Kuiper Belt. Belt. So
00:00:31 --> 00:00:34 buckle up for this episode of space
00:00:34 --> 00:00:34 nuts.
00:00:34 --> 00:00:37 Voice Over Guy: 15 seconds. Guidance is internal.
00:00:37 --> 00:00:40 10, 9. Ignition
00:00:40 --> 00:00:43 sequence start. Space nuts. 5, 4, 3,
00:00:43 --> 00:00:46 2. 1. 2, 3, 4, 5, 5, 4,
00:00:46 --> 00:00:49 3, 2, 1. Space nuts. Astronauts
00:00:49 --> 00:00:52 report it feels good. And back with us
00:00:52 --> 00:00:54 again is Professor Fred Watson Watson,
00:00:54 --> 00:00:56 astronomer at large. Hello, Fred.
00:00:56 --> 00:00:58 Professor Fred Watson: Hello, Andrew. Hello. Took me in couple.
00:00:58 --> 00:01:00 Couple of seconds. But I did get the.
00:01:00 --> 00:01:02 Andrew Dunkley: To get the, flesh. The flesh wound. Flesh
00:01:02 --> 00:01:04 wound. The Grail mission.
00:01:04 --> 00:01:05 Professor Fred Watson: Only a flesh wound.
00:01:05 --> 00:01:06 Andrew Dunkley: It's only a flesh wound.
00:01:06 --> 00:01:09 Professor Fred Watson: That's right. no arms, no legs, but
00:01:09 --> 00:01:10 nothing.
00:01:11 --> 00:01:14 Andrew Dunkley: Flesh wound. so, yes, that I,
00:01:14 --> 00:01:17 I can't help dad jokes and, and, and
00:01:18 --> 00:01:21 I, I. When I do the presentations at golf on
00:01:21 --> 00:01:24 Fridays, which has become my job somehow.
00:01:24 --> 00:01:26 I always have to finish on a dad joke. It's
00:01:26 --> 00:01:27 just become a thing.
00:01:28 --> 00:01:30 Professor Fred Watson: Yes, yes, I'm sure it has.
00:01:31 --> 00:01:33 Andrew Dunkley: The reputation continues to spread. we'll be
00:01:33 --> 00:01:36 talking dad jokes in our next episode,
00:01:36 --> 00:01:38 our Q A episode as well.
00:01:39 --> 00:01:41 we should begin with this,
00:01:41 --> 00:01:44 Grail mission and the findings of the moon's
00:01:44 --> 00:01:47 unusual interior. This might
00:01:47 --> 00:01:49 come as a surprise to some people.
00:01:50 --> 00:01:52 Professor Fred Watson: Well, I think it does. Excuse me. I think it
00:01:52 --> 00:01:54 did come as a surprise when the discovery was
00:01:54 --> 00:01:57 made as well. These, are, scientists from
00:01:57 --> 00:01:59 NASA and other institutions, missions.
00:02:01 --> 00:02:03 yeah, let's do the dad joke first. The, It's
00:02:03 --> 00:02:05 not Monty Python and the Holy Grail.
00:02:07 --> 00:02:10 Grail stands for Gravity Recovery and
00:02:10 --> 00:02:13 Interior Laboratory. And it was a mission,
00:02:13 --> 00:02:16 which I guess it was more than. It's probably
00:02:16 --> 00:02:19 a decade ago. it's a very, very
00:02:19 --> 00:02:21 neat piece, of research. And
00:02:21 --> 00:02:24 NASA, you know, the clever stuff that they do
00:02:24 --> 00:02:25 is just unbelievable.
00:02:26 --> 00:02:28 so what do you do if you want to sense the
00:02:28 --> 00:02:31 gravity of, a planet that
00:02:31 --> 00:02:33 you're flying over? You want to map out the
00:02:33 --> 00:02:36 gravitational details. And by doing
00:02:36 --> 00:02:38 that, you can work out what's underneath the
00:02:38 --> 00:02:41 surface. because that's usually what
00:02:41 --> 00:02:43 affects the gravity above the surface of
00:02:44 --> 00:02:47 a planet. And I'm Talking now about really
00:02:48 --> 00:02:50 minor, disorder, differences and
00:02:50 --> 00:02:53 discrepancies in gravity, how the
00:02:53 --> 00:02:56 Grail mission worked. and I'm kind of casting
00:02:56 --> 00:02:59 my memory back now. two spacecraft,
00:02:59 --> 00:03:01 in orbit around the Moon,
00:03:02 --> 00:03:04 separate in the same. They're both in the
00:03:04 --> 00:03:07 same orbit. They were separated, I think, by
00:03:07 --> 00:03:09 about 200 kilometres, one in front of the
00:03:09 --> 00:03:12 other. But the
00:03:12 --> 00:03:15 distance between them could be detected
00:03:15 --> 00:03:17 by microwave transmission
00:03:18 --> 00:03:20 to well under a millimetre. I can't remember
00:03:20 --> 00:03:23 what it was. It was a few microns, I think.
00:03:23 --> 00:03:25 But this tiny, tiny difference between
00:03:26 --> 00:03:29 the position of the two spacecraft, you can
00:03:29 --> 00:03:32 measure it, by these microwave signals. And
00:03:32 --> 00:03:34 so as the two spacecraft go around the moon,
00:03:35 --> 00:03:38 their separation changes slightly as a
00:03:38 --> 00:03:39 result of the gravitational force,
00:03:40 --> 00:03:42 gravitational pull of the terrain beneath
00:03:42 --> 00:03:45 them. and it actually is
00:03:46 --> 00:03:49 a, really very sensitive way. I love the fact
00:03:49 --> 00:03:51 that they rediscovered, something that we
00:03:51 --> 00:03:54 talked about in the very earliest, history of
00:03:54 --> 00:03:57 moon exploration. Back in the, Gemini and
00:03:57 --> 00:03:59 Apollo era, back in the 19, 60s,
00:04:00 --> 00:04:03 mass, cons, which were mass concentrations,
00:04:03 --> 00:04:05 concentrations of mass that were unexpected
00:04:05 --> 00:04:07 underneath the Moon's surface. They were
00:04:07 --> 00:04:09 actually measured just by spacecraft that
00:04:09 --> 00:04:11 were orbiting. Single spacecraft orbiting
00:04:12 --> 00:04:15 the Moon. but, GRAIL actually mapped them out
00:04:15 --> 00:04:17 in much more detail. We know a lot more about
00:04:17 --> 00:04:19 these mascons now than we did before. But
00:04:19 --> 00:04:22 what has happened, and by the way, I should
00:04:22 --> 00:04:25 just mention one, I should have put this in
00:04:25 --> 00:04:27 as a, As a quirky factoid, shouldn't I?
00:04:27 --> 00:04:29 Flippant factoid that the two,
00:04:30 --> 00:04:32 spacecraft, the two components of Grail. Do
00:04:32 --> 00:04:33 you remember what they were called?
00:04:34 --> 00:04:37 Andrew Dunkley: Oh, no.
00:04:37 --> 00:04:40 Professor Fred Watson: Ebb and flow. And it came.
00:04:40 --> 00:04:43 I think it was school kids who did that. If I
00:04:43 --> 00:04:45 remember rightly, NASA sent out a competition
00:04:45 --> 00:04:47 saying, we've got two spacecraft in orbit
00:04:47 --> 00:04:48 around the Moon. What do you want to call
00:04:48 --> 00:04:50 them? And they were called ebb and flow,
00:04:50 --> 00:04:52 which is very, very nice indeed.
00:04:53 --> 00:04:55 Anyway, ebb and flow, in combination,
00:04:55 --> 00:04:58 measured, virtually the gravitational map of
00:04:58 --> 00:05:01 the whole Moon. But what has
00:05:02 --> 00:05:05 come to light is something a little bit
00:05:05 --> 00:05:08 more subtle. these, researchers who've now
00:05:08 --> 00:05:11 used these NASA data to deduce
00:05:11 --> 00:05:13 that There's a, 2 to 3%
00:05:14 --> 00:05:17 difference in the
00:05:17 --> 00:05:20 ability of the lunar mantle. Now, that's
00:05:20 --> 00:05:22 the layer below the crust. That's the
00:05:23 --> 00:05:25 layer that surrounds the core of the Moon.
00:05:25 --> 00:05:28 The ability of the mantle to
00:05:28 --> 00:05:31 deform. So what you're
00:05:31 --> 00:05:34 saying is there's a difference in sort of
00:05:34 --> 00:05:37 flexibility from one side of the Moon to the
00:05:37 --> 00:05:39 other. And remember, as we know The Moon
00:05:39 --> 00:05:41 always faces the same side to Earth. and
00:05:41 --> 00:05:43 so that's, you know, there's a different
00:05:43 --> 00:05:45 gravitational pull on one side from what
00:05:45 --> 00:05:47 there is on the other. but what they've
00:05:47 --> 00:05:49 interpreted this difference as being,
00:05:50 --> 00:05:53 they say it's symptomatic. The fact that
00:05:53 --> 00:05:55 there's this difference in the Moon's mantles
00:05:56 --> 00:05:59 ability to deform, to change its
00:05:59 --> 00:06:02 shape. they say that is
00:06:02 --> 00:06:05 best explained by the
00:06:05 --> 00:06:07 temperature inside the mantle
00:06:08 --> 00:06:10 on the near side being as much
00:06:10 --> 00:06:13 as 170 degrees Celsius
00:06:13 --> 00:06:16 hotter than what it is on the other side.
00:06:16 --> 00:06:18 Wow, that's a side facing us. Yeah, it is.
00:06:18 --> 00:06:20 It's not a small amount, it's not a few
00:06:20 --> 00:06:23 degrees, it's a lot. and it's enough to
00:06:23 --> 00:06:26 change the viscosity of the mantle, how
00:06:26 --> 00:06:29 flexible it is. and so that's
00:06:29 --> 00:06:32 the new finding that's come from ebb
00:06:32 --> 00:06:34 and flow. And I think what they're saying is
00:06:34 --> 00:06:36 that the spacecraft was in orbit for long
00:06:36 --> 00:06:39 enough that it could detect differences in
00:06:39 --> 00:06:41 the gravitational pull as it flew over the
00:06:41 --> 00:06:44 same part of the Moon more than once. It
00:06:44 --> 00:06:46 could see a difference in the gravitational
00:06:46 --> 00:06:48 pull from one trip to another. So there's a
00:06:48 --> 00:06:50 time dependent thing on it, and that's how
00:06:50 --> 00:06:53 they know about the Moon's ability
00:06:53 --> 00:06:55 to deform. I'm actually, interpreting that in
00:06:55 --> 00:06:58 my own way. There's a nice
00:06:58 --> 00:07:01 paper in Nature magazine, perhaps
00:07:01 --> 00:07:03 one of the two leading journals for science
00:07:03 --> 00:07:06 in the world, which has the title of thermal
00:07:06 --> 00:07:09 asymmetry in the Moon's mantle inferred from
00:07:09 --> 00:07:10 monthly tidal response.
00:07:11 --> 00:07:13 Andrew Dunkley: Okay, so my question
00:07:13 --> 00:07:16 straight up is, could that explain,
00:07:16 --> 00:07:19 or does that explain why the near side
00:07:19 --> 00:07:22 and the far side of the Moon are so
00:07:22 --> 00:07:24 very different? when you're talking
00:07:24 --> 00:07:26 topography, yeah, I.
00:07:26 --> 00:07:28 Professor Fred Watson: Think it's the other way around. I suspect
00:07:28 --> 00:07:30 the difference in topography is,
00:07:31 --> 00:07:33 what causes the difference. Although they're
00:07:33 --> 00:07:36 probably all mishmashed up,
00:07:38 --> 00:07:40 into the same sort of thing.
00:07:41 --> 00:07:42 But the Moon's nearside,
00:07:43 --> 00:07:45 I think probably the way you've put it,
00:07:45 --> 00:07:47 actually Andrew, is probably more correct.
00:07:47 --> 00:07:50 The Moon's nearside, has had much
00:07:50 --> 00:07:53 more volcanic activity than the far side.
00:07:53 --> 00:07:56 This is between 3 and 4 billion years ago. It
00:07:56 --> 00:07:58 was highly volcanically active, which is why
00:07:58 --> 00:08:00 we've got all these lava flows on the near
00:08:00 --> 00:08:03 side, which we see as the maria, the grey
00:08:03 --> 00:08:06 patches on the Moon. but the
00:08:06 --> 00:08:08 details of what these
00:08:08 --> 00:08:11 researchers think, contributes to
00:08:11 --> 00:08:14 the difference, in temperature, they
00:08:14 --> 00:08:17 suggest I might actually, I think this is
00:08:17 --> 00:08:19 Nature's press release So I might just read
00:08:19 --> 00:08:20 straight from it.
00:08:22 --> 00:08:25 they hypothesise that this thermal
00:08:25 --> 00:08:28 difference could be sustained by radioactive
00:08:28 --> 00:08:31 decay of thorium and titanium within the
00:08:31 --> 00:08:33 moon's near side, which could be a
00:08:33 --> 00:08:36 remnant of the volcanic activity that formed
00:08:36 --> 00:08:38 the near side surface 3 to 4 billion years
00:08:38 --> 00:08:39 ago.
00:08:40 --> 00:08:42 Andrew Dunkley: That is really interesting. Yeah,
00:08:43 --> 00:08:46 I'm fascinated
00:08:46 --> 00:08:48 by a couple of things, that we're using old
00:08:48 --> 00:08:50 data to make new discoveries. We've talked
00:08:50 --> 00:08:52 about that in other studies that have more
00:08:52 --> 00:08:54 papers that have been released in recent
00:08:54 --> 00:08:57 years. also the fact that there's
00:08:57 --> 00:09:00 effects on the moon that we see in
00:09:00 --> 00:09:02 other parts of the solar system, with, with
00:09:03 --> 00:09:05 variations in the way the moons
00:09:07 --> 00:09:09 interact with their host planet for example.
00:09:09 --> 00:09:10 I suppose.
00:09:10 --> 00:09:11 Professor Fred Watson: Yes.
00:09:11 --> 00:09:13 Andrew Dunkley: It's a similar situation is it not?
00:09:13 --> 00:09:15 Professor Fred Watson: Yes, that's right. So you've got and in fact
00:09:15 --> 00:09:18 most of these moons around, certainly the
00:09:18 --> 00:09:21 giant planets are ah, which is where most of
00:09:21 --> 00:09:23 the moons in the solar system are. there's
00:09:23 --> 00:09:25 only three in the inner solar system. Ours
00:09:25 --> 00:09:28 and Mars is two little satellites.
00:09:28 --> 00:09:31 But places like Enceladus, Ganymede, perhaps
00:09:31 --> 00:09:34 Callisto, Europa, around Jupiter, perhaps
00:09:34 --> 00:09:36 Titan as well, they,
00:09:37 --> 00:09:40 they could do use
00:09:40 --> 00:09:43 this technology to
00:09:44 --> 00:09:46 actually interpret what's going on
00:09:46 --> 00:09:49 inside these worlds without having to land
00:09:49 --> 00:09:52 a spacecraft on the surface. That's the,
00:09:52 --> 00:09:54 the great thing because putting something
00:09:54 --> 00:09:56 into orbit around Enceladus for example,
00:09:57 --> 00:10:00 would be much more straightforward, much
00:10:00 --> 00:10:03 less energy hungry than putting a
00:10:03 --> 00:10:05 spacecraft down onto the surface where you've
00:10:05 --> 00:10:08 got all the risks of collisions and tipping
00:10:08 --> 00:10:10 over like several of the lunar probes have
00:10:10 --> 00:10:13 done, they've fallen over. all of that is
00:10:13 --> 00:10:16 the hazard when you're landing something on
00:10:16 --> 00:10:19 the surface. So yeah, I think it's got a
00:10:19 --> 00:10:22 future. Now. you can, as I
00:10:22 --> 00:10:24 kind of mentioned earlier, you can do some of
00:10:24 --> 00:10:27 this kind of work with a single spacecraft,
00:10:27 --> 00:10:29 but if you can launch two with this
00:10:29 --> 00:10:31 microwave, microwave bridge between them,
00:10:31 --> 00:10:34 then you can do much, much more as the
00:10:34 --> 00:10:36 Grail spacecraft demonstrated.
00:10:36 --> 00:10:39 Andrew Dunkley: Okay, so yeah, the moon is not as
00:10:39 --> 00:10:42 it seems, at least not on the inside.
00:10:42 --> 00:10:45 Professor Fred Watson: Well no, that's right. Or maybe, maybe it is
00:10:45 --> 00:10:48 as it seems because the two sides are so
00:10:48 --> 00:10:50 different when you look at them. As you said,
00:10:50 --> 00:10:53 the topography is quite different from one
00:10:53 --> 00:10:54 side to the other.
00:10:54 --> 00:10:56 Andrew Dunkley: It's a great story. If you'd like to read up
00:10:56 --> 00:10:58 on that, you can find, you can go find the
00:10:58 --> 00:11:00 paper if you can remember the title of it
00:11:00 --> 00:11:02 because it's got more than three words in it.
00:11:02 --> 00:11:04 So I'm stuffed. But yeah,
00:11:04 --> 00:11:06 DailyGalaxy.com is the website.
00:11:06 --> 00:11:09 DailyGalaxy.com this is
00:11:09 --> 00:11:12 space Nuts with Andrew Dunkley and Professor
00:11:12 --> 00:11:13 Fred Watson Watson.
00:11:16 --> 00:11:18 Three, two, one.
00:11:18 --> 00:11:20 Professor Fred Watson: Space Nuts.
00:11:20 --> 00:11:23 Andrew Dunkley: Fred Watson, I neglected to mention my office
00:11:23 --> 00:11:26 background at the beginning. if I just put my
00:11:26 --> 00:11:29 thumb over the camera, people on YouTube will
00:11:29 --> 00:11:31 see a massive mountain there. That's the Fugo
00:11:31 --> 00:11:34 volcano in Guatemala. I took that photo on
00:11:34 --> 00:11:37 the 7th of April. And Judy and
00:11:37 --> 00:11:39 I have a history of visiting volcanoes,
00:11:39 --> 00:11:40 getting home and then finding out they
00:11:40 --> 00:11:42 started erupting. And that's exactly what's
00:11:42 --> 00:11:45 happened with Fugo. So if you're on YouTube
00:11:45 --> 00:11:47 and you're watching us, when we're finished,
00:11:47 --> 00:11:49 go and have a look at some of the eruption
00:11:49 --> 00:11:52 footage from the Fugo volcano in Guatemala at
00:11:52 --> 00:11:55 the moment. It is spectacular. We had to
00:11:55 --> 00:11:57 drive between three volcanoes to
00:11:57 --> 00:12:00 get to the township of Antigua
00:12:00 --> 00:12:03 and you could see these things for
00:12:03 --> 00:12:05 miles. I mean they're strata volcanoes, they
00:12:05 --> 00:12:08 are absolutely enormous. They're
00:12:08 --> 00:12:11 around 12, 13ft at the peak
00:12:11 --> 00:12:14 above sea level. and they
00:12:14 --> 00:12:16 are spectacular. And we literally had to
00:12:16 --> 00:12:18 drive between two of them to get to the town.
00:12:19 --> 00:12:21 That one was on our left and the
00:12:21 --> 00:12:24 agua volcano was on our right. and
00:12:24 --> 00:12:26 the town is in the foothills of the the two
00:12:27 --> 00:12:29 nearest volcanoes. And it's just an
00:12:29 --> 00:12:32 awe inspiring sight. But I just thought it
00:12:32 --> 00:12:34 was funny that well maybe not funny haha, but
00:12:34 --> 00:12:37 funny that we went to Hawaii, got home
00:12:37 --> 00:12:40 and Kilauea erupted. Happens a lot.
00:12:40 --> 00:12:43 I went to Vanuatu, Matt Yasser, got home, it
00:12:43 --> 00:12:45 erupted and stopped air traffic for a couple
00:12:45 --> 00:12:48 of weeks. And now this one's erupting a month
00:12:48 --> 00:12:50 after we were there. So we're not going to be
00:12:50 --> 00:12:52 invited back I don't think. But
00:12:53 --> 00:12:55 Fugo's got a history though it erupts quite
00:12:55 --> 00:12:57 often. But I just thought people would be
00:12:57 --> 00:13:00 interested to see a photo of it. as you know,
00:13:00 --> 00:13:01 I'm a volcano junkie.
00:13:02 --> 00:13:04 Professor Fred Watson: So when we were in Iceland earlier in the
00:13:04 --> 00:13:07 year, the Reykjanes peninsula had
00:13:07 --> 00:13:10 just erupted as well. Well here there was
00:13:10 --> 00:13:12 a lot of steam coming up from from the, you
00:13:12 --> 00:13:14 know, the fishes in the ground.
00:13:14 --> 00:13:16 Andrew Dunkley: Yeah. In the next few months we'll be
00:13:16 --> 00:13:18 visiting the Canary Islands.
00:13:19 --> 00:13:19 Professor Fred Watson: Sure.
00:13:20 --> 00:13:23 Andrew Dunkley: Yeah. So that one's got an active volcano
00:13:23 --> 00:13:25 and we're visiting Iceland as well.
00:13:26 --> 00:13:28 yeah. Could, could have some stories to tell.
00:13:28 --> 00:13:29 Professor Fred Watson: Yeah.
00:13:29 --> 00:13:32 Andrew Dunkley: Ah, good. Okay Fred Watson, let's move on
00:13:32 --> 00:13:32 to our next story.
00:13:32 --> 00:13:35 And this one is about yet again,
00:13:36 --> 00:13:39 the Hubble tension, the, the
00:13:39 --> 00:13:41 quirk of space that we
00:13:42 --> 00:13:44 can't quite get our heads around. We can't
00:13:44 --> 00:13:47 solve the differentials or the problems. Many
00:13:47 --> 00:13:49 are saying, look, it's natural. But
00:13:50 --> 00:13:52 Now another Hubble
00:13:52 --> 00:13:54 Tension theory, gee that's hard to say.
00:13:56 --> 00:13:59 is making its way into various papers. one in
00:13:59 --> 00:14:01 particular I suspect, because now they're
00:14:01 --> 00:14:04 talking about evolution in
00:14:04 --> 00:14:06 dark matter. This sounds like
00:14:07 --> 00:14:10 pie in the sky type stuff but we've got
00:14:10 --> 00:14:11 to, we've got to come up with answers. The
00:14:11 --> 00:14:14 only way it is to publish papers with
00:14:14 --> 00:14:16 theories and you know,
00:14:16 --> 00:14:17 toss it around.
00:14:19 --> 00:14:19 Professor Fred Watson: Indeed.
00:14:19 --> 00:14:22 Andrew Dunkley: That's like, like a salad. A space
00:14:22 --> 00:14:23 salad.
00:14:25 --> 00:14:27 Professor Fred Watson: yeah, I've just I'm m hesitating because I've
00:14:27 --> 00:14:29 just seen who one of the authors of this
00:14:29 --> 00:14:29 paper is.
00:14:32 --> 00:14:34 it's a scientist who's known for
00:14:34 --> 00:14:37 provocative papers. Avi
00:14:37 --> 00:14:40 Loeb, and he's at Harvard, Smithsonian,
00:14:41 --> 00:14:44 Centre for Astrophysics. So the
00:14:44 --> 00:14:45 paper that we're talking about is called
00:14:45 --> 00:14:48 Evolving Dark Energy or Evolving Dark
00:14:48 --> 00:14:51 Matter. and this
00:14:51 --> 00:14:53 is really esoteric stuff, Andrew.
00:14:54 --> 00:14:55 Always when we're talking about this stuff
00:14:56 --> 00:14:58 we're just glossing over
00:14:59 --> 00:15:01 a lot of really detailed
00:15:02 --> 00:15:05 science that goes into
00:15:05 --> 00:15:08 realms that even I struggle with. And I'm not
00:15:08 --> 00:15:10 actually a cosmologist, which is why. But
00:15:10 --> 00:15:12 I'm supposed to know my way around some of
00:15:12 --> 00:15:15 these topics better than perhaps
00:15:15 --> 00:15:17 the person in the street is.
00:15:18 --> 00:15:21 and this
00:15:21 --> 00:15:22 comes down to something called the equation
00:15:22 --> 00:15:24 of states which you and I haven't talked
00:15:24 --> 00:15:27 about. But the equation of state is a
00:15:27 --> 00:15:30 parameter in the universe. It's a parameter
00:15:30 --> 00:15:32 generally. It comes from thermodynamics,
00:15:33 --> 00:15:36 which essentially characterises,
00:15:37 --> 00:15:39 as the name almost implies, it
00:15:39 --> 00:15:42 characterises the overall behaviour of the
00:15:42 --> 00:15:44 universe. The equation of states, okay,
00:15:44 --> 00:15:46 Symbolised by the, the character W.
00:15:49 --> 00:15:52 so the, the work that's
00:15:52 --> 00:15:54 being reported here. and as I've said
00:15:54 --> 00:15:57 it's on a, on a, there's a, there's a.
00:15:58 --> 00:16:01 Basically a preprint as we used
00:16:01 --> 00:16:03 to call them. this is a paper that's not yet
00:16:03 --> 00:16:06 been refereed which is
00:16:07 --> 00:16:10 going to go into. I can't see
00:16:10 --> 00:16:13 what journal it's aiming for but it
00:16:13 --> 00:16:14 is called
00:16:15 --> 00:16:18 essentially the title of the paper Evolving
00:16:18 --> 00:16:20 Dark Energy or Evolving Dark Matter. I'm
00:16:20 --> 00:16:22 going to read you the abstract, okay?
00:16:23 --> 00:16:26 because that kind of tells the story even
00:16:26 --> 00:16:29 if you don't know what the details are.
00:16:29 --> 00:16:31 We show that the latest
00:16:32 --> 00:16:35 empirical constraints on cosmology, and by
00:16:35 --> 00:16:37 that they mean measured, from a Combination
00:16:37 --> 00:16:40 of desi, that's the Dark Energy Survey
00:16:40 --> 00:16:43 instrument cmb, that's the cosmic
00:16:43 --> 00:16:45 microwave background and supernova data,
00:16:45 --> 00:16:48 that's exploding stars. They've taken all
00:16:48 --> 00:16:51 this data together. The empirical
00:16:51 --> 00:16:52 constraints on cosmology from that
00:16:52 --> 00:16:55 combination can be accounted for. If
00:16:55 --> 00:16:58 a small component of dark matter
00:16:59 --> 00:17:02 has an evolving and oscillating
00:17:02 --> 00:17:05 equation of state within the range minus
00:17:05 --> 00:17:08 1 is greater than less than w, which is
00:17:08 --> 00:17:11 less than 1, that's the range minus 1 to 1 is
00:17:11 --> 00:17:13 somewhere where this equation of state
00:17:13 --> 00:17:16 parameter, W lies. From a fundamental physics
00:17:16 --> 00:17:18 perspective, this interpretation is more
00:17:18 --> 00:17:21 appealing than an evolving phantom
00:17:21 --> 00:17:24 dark energy with W less than minus
00:17:24 --> 00:17:26 1, which violates the null energy
00:17:26 --> 00:17:29 condition. So in a sense
00:17:29 --> 00:17:32 this paper is kind of in response
00:17:33 --> 00:17:35 to what we're seeing from the latest data
00:17:35 --> 00:17:38 actually from desi, the Dark Energy Survey,
00:17:39 --> 00:17:42 which suggests that dark
00:17:42 --> 00:17:45 energy is getting less.
00:17:45 --> 00:17:47 Or at least what it suggests is the
00:17:47 --> 00:17:50 acceleration of the universe's expansion is
00:17:50 --> 00:17:52 getting less. In other words, the expansion
00:17:52 --> 00:17:54 which we know is accelerating because that's
00:17:54 --> 00:17:57 been well measured. But the suggestion is
00:17:57 --> 00:18:00 that that acceleration is slowing down,
00:18:00 --> 00:18:03 so as time goes on it will be accelerating at
00:18:03 --> 00:18:06 a lower rate. What they're saying is,
00:18:07 --> 00:18:09 when you look at the sort of theory that
00:18:09 --> 00:18:12 doesn't make sense, but it makes more sense
00:18:12 --> 00:18:15 if something is going on with
00:18:15 --> 00:18:18 dark matter, that dark matter,
00:18:19 --> 00:18:21 is itself evolving. Now
00:18:22 --> 00:18:25 that suggests, and they apparently
00:18:25 --> 00:18:27 explore this in the paper, I haven't read the
00:18:27 --> 00:18:30 paper, but they explore this, that suggests
00:18:30 --> 00:18:33 that dark matter is something different from
00:18:33 --> 00:18:35 what we think it is because we imagine dark
00:18:35 --> 00:18:38 matter as being some subatomic particle,
00:18:38 --> 00:18:41 which is as yet unknown, which does not
00:18:41 --> 00:18:43 interact with normal matter at all, which is
00:18:43 --> 00:18:46 why we can't see it, and all it reveals
00:18:46 --> 00:18:49 itself by is its gravity. That's the
00:18:49 --> 00:18:51 parameters that we understand dark matter to
00:18:51 --> 00:18:54 be. But what they're suggesting
00:18:54 --> 00:18:57 is that this is something even more
00:18:57 --> 00:19:00 exotic than we have been imagining,
00:19:00 --> 00:19:03 because its parameters
00:19:03 --> 00:19:06 change, its phenomena change and
00:19:06 --> 00:19:09 that leads to a changed equation of state,
00:19:09 --> 00:19:11 the W parameter.
00:19:14 --> 00:19:16 And they actually suggest,
00:19:17 --> 00:19:19 that actually there's some sort of
00:19:19 --> 00:19:22 oscillation going on in it as well. Not just
00:19:22 --> 00:19:25 dark matter. There's a very nice article on
00:19:25 --> 00:19:26 physics phys.org
00:19:28 --> 00:19:30 by Brian Koberlein. I'm going to read
00:19:30 --> 00:19:32 a paragraph for it.
00:19:34 --> 00:19:36 in fact I'm going to read a couple,
00:19:37 --> 00:19:39 let me just read from this because I think
00:19:39 --> 00:19:41 that's going to explain it better than me
00:19:41 --> 00:19:44 waffling on. In work published on the
00:19:44 --> 00:19:46 Arxivist print server, the Authors look at
00:19:46 --> 00:19:49 both evolving dark energy and evolving dark
00:19:49 --> 00:19:52 matter and argue that the latter is a much
00:19:52 --> 00:19:54 better fit to the observational data. The
00:19:54 --> 00:19:55 first thing they know is that the two models
00:19:55 --> 00:19:58 are somewhat related. Since the evolution of
00:19:58 --> 00:20:01 the cosmos depends in part on the ratio of
00:20:01 --> 00:20:04 dark energy to matter density, a model
00:20:04 --> 00:20:06 with constant dark matter, which is what we
00:20:06 --> 00:20:08 have at the moment, and evolving dark energy,
00:20:09 --> 00:20:12 will always appear similar to a model with
00:20:12 --> 00:20:14 evolving dark matter and a constant dark
00:20:14 --> 00:20:17 energy. That's a good point. They then go on
00:20:17 --> 00:20:19 to explore the idea of some kind of exotic
00:20:19 --> 00:20:21 dark matter, one that has a changeable
00:20:21 --> 00:20:23 equation of state to match observation. The
00:20:23 --> 00:20:26 dark matter equation of state must
00:20:26 --> 00:20:29 oscillate in time. This isn't an
00:20:29 --> 00:20:31 outlandish notion. I think
00:20:31 --> 00:20:33 they're trying to convince us here in
00:20:33 --> 00:20:36 space.org neutrinos have mass
00:20:36 --> 00:20:39 and don't interact strongly with light. While
00:20:39 --> 00:20:40 they can't account for all the dark matter in
00:20:40 --> 00:20:43 the universe, they are a form of hot dark
00:20:43 --> 00:20:45 matter. And neutrinos undergo, mass
00:20:45 --> 00:20:48 oscillation. Perhaps cold and dark
00:20:48 --> 00:20:51 matter particles undergo, Sorry. Perhaps cold
00:20:51 --> 00:20:53 dark matter particles undergo a similar
00:20:54 --> 00:20:57 oscillatory, effect. The authors find
00:20:58 --> 00:21:00 that the best fit to observational data is a
00:21:00 --> 00:21:03 universe where about 15% of the cold dark
00:21:03 --> 00:21:05 matter is oscillatory, and the
00:21:05 --> 00:21:08 remaining 85% is standard dark
00:21:08 --> 00:21:11 matter. This would allow for the Hubble
00:21:11 --> 00:21:14 tension to be covered while still matching
00:21:14 --> 00:21:16 the dark matter observations we have.
00:21:16 --> 00:21:18 And I love the last paragraph.
00:21:18 --> 00:21:20 Andrew Dunkley: Yeah, I do too. I was just reading it.
00:21:20 --> 00:21:23 Professor Fred Watson: It should be stressed that this work presents
00:21:23 --> 00:21:26 a toy model. As the authors themselves note,
00:21:26 --> 00:21:28 the work is a broad concept that does not pin
00:21:28 --> 00:21:30 down specific constraints for dark matter
00:21:30 --> 00:21:32 particles. But the work does open the door to
00:21:32 --> 00:21:34 a broader range of dark matter models. At
00:21:34 --> 00:21:36 this point, evolving dark matter is worth
00:21:36 --> 00:21:38 considering. Well, I agree with that. I think
00:21:38 --> 00:21:40 everything's worth calling.
00:21:40 --> 00:21:42 Andrew Dunkley: I was going to ask you where you stand on
00:21:42 --> 00:21:44 this and if it's worth considering, then
00:21:44 --> 00:21:47 obviously it is. But it
00:21:47 --> 00:21:49 just adds another potential
00:21:50 --> 00:21:53 explanation of something we know very little
00:21:53 --> 00:21:54 about and.
00:21:54 --> 00:21:57 Professor Fred Watson: Yep. And we worry about a lot, especially
00:21:57 --> 00:21:58 on space. Nuts.
00:21:58 --> 00:22:01 Andrew Dunkley: Yes, yes. And we get a lot of questions about
00:22:01 --> 00:22:03 it. And so a lot of people thinking about
00:22:03 --> 00:22:06 this stuff, if it's, if it's in fact
00:22:06 --> 00:22:06 stuff.
00:22:07 --> 00:22:09 Professor Fred Watson: Yes, well, yes, that's right. It could be
00:22:09 --> 00:22:10 something other than stuff.
00:22:10 --> 00:22:13 Andrew Dunkley: Yes, yes. So, yeah, it's a
00:22:13 --> 00:22:16 really interesting idea and, well, I
00:22:16 --> 00:22:18 suppose, it'll get tossed around and people
00:22:18 --> 00:22:20 will come up with other explanations. But the
00:22:20 --> 00:22:23 thing is, a paper like this, even if it's
00:22:23 --> 00:22:26 wrong may spawn a level of thinking
00:22:26 --> 00:22:28 that might send us down a path where we might
00:22:28 --> 00:22:29 eventually figure it out. I mean that's
00:22:29 --> 00:22:30 another possibility.
00:22:31 --> 00:22:33 Professor Fred Watson: that's, that's true. That's correct.
00:22:34 --> 00:22:36 and that's the way science works as well.
00:22:36 --> 00:22:37 Exactly as you've said.
00:22:37 --> 00:22:38 Yes, indeed.
00:22:38 --> 00:22:41 Andrew Dunkley: All right. as Fred Watson said, you can read
00:22:41 --> 00:22:44 all about it@the phys.org website. That's
00:22:44 --> 00:22:47 P-Y-S.org or you can
00:22:47 --> 00:22:49 read the published paper on the archive
00:22:49 --> 00:22:52 reprint server if you like. This is Space
00:22:52 --> 00:22:54 Nuts. Andrew Dunkley here, Fred Watson Watson
00:22:54 --> 00:22:54 there.
00:22:57 --> 00:22:58 Okay, we checked all four systems.
00:23:01 --> 00:23:03 Our final topic today, Fred Watson,
00:23:04 --> 00:23:06 is a really interesting one and it
00:23:06 --> 00:23:09 is going to take us to the Kuiper
00:23:09 --> 00:23:09 Belt.
00:23:09 --> 00:23:12 So tighten up your buckle and get ready for
00:23:12 --> 00:23:15 this one because we think there has
00:23:15 --> 00:23:18 been discovered a triple system in the Kuiper
00:23:18 --> 00:23:21 Belt. Now when we talk about the Kuiper
00:23:21 --> 00:23:24 Belt we don't really, we've only been there a
00:23:24 --> 00:23:27 couple of times. fairly recent missions in
00:23:27 --> 00:23:30 the last decade or so. But we've only had
00:23:30 --> 00:23:33 close up observations of two objects
00:23:33 --> 00:23:35 in the Kuiper Belt. So
00:23:36 --> 00:23:39 this discovery was actually made not by
00:23:39 --> 00:23:42 either of those probes but, or the
00:23:42 --> 00:23:44 probe in question. it was made from
00:23:44 --> 00:23:46 Earth, am I correct?
00:23:46 --> 00:23:49 Professor Fred Watson: Yes, that's right. using the Hubble
00:23:49 --> 00:23:50 Space Telescope.
00:23:50 --> 00:23:51 Andrew Dunkley: Yeah.
00:23:52 --> 00:23:54 Professor Fred Watson: Which is you know, still going strong
00:23:54 --> 00:23:57 and still a
00:23:57 --> 00:23:58 fantastic resource
00:24:00 --> 00:24:02 given that it's now 35 years
00:24:03 --> 00:24:05 in space. Yes, it is amazing. That's
00:24:05 --> 00:24:08 right. so, and again this is a team
00:24:08 --> 00:24:11 of researchers from NASA. what they've been
00:24:11 --> 00:24:13 doing is looking through ah, Hubble
00:24:13 --> 00:24:16 telescope data at this very distant
00:24:17 --> 00:24:19 object which is it's a,
00:24:20 --> 00:24:21 an asteroid. So it's got a number
00:24:21 --> 00:24:24 148780 and
00:24:24 --> 00:24:27 it's known as Algeria. that's its name.
00:24:27 --> 00:24:30 and they, they,
00:24:31 --> 00:24:33 they haven't seen the three
00:24:33 --> 00:24:36 bodies that they now think make it up, but
00:24:36 --> 00:24:37 they've seen two.
00:24:37 --> 00:24:38 Andrew Dunkley: Wait, dad, joke coming.
00:24:39 --> 00:24:40 Professor Fred Watson: Oh good. Okay. They're seeing two of them.
00:24:42 --> 00:24:43 Andrew Dunkley: I was going so they haven't seen the three
00:24:43 --> 00:24:44 bodies. That's a problem.
00:24:45 --> 00:24:48 Professor Fred Watson: Oh, there we go. Love it. Love
00:24:48 --> 00:24:51 it. I
00:24:51 --> 00:24:52 don't understand. You must rehearse our
00:24:52 --> 00:24:54 conversations weeks in advance, Andrew, to
00:24:54 --> 00:24:55 get.
00:24:55 --> 00:24:57 Andrew Dunkley: No, the scary part is this
00:24:57 --> 00:24:59 garbage just pops in there
00:25:00 --> 00:25:03 at random moments. It used to happen
00:25:03 --> 00:25:05 when I was on the radio. I'd just be talking
00:25:05 --> 00:25:08 about something and a little voice ago,
00:25:08 --> 00:25:09 hey, tell this joke.
00:25:10 --> 00:25:12 Professor Fred Watson: Yeah. And then at the end of it you think I
00:25:12 --> 00:25:14 got a Wish I hadn't said that.
00:25:15 --> 00:25:15 Yes, yeah.
00:25:15 --> 00:25:17 Andrew Dunkley: Ah, yeah, yeah.
00:25:17 --> 00:25:20 Professor Fred Watson: Anyway, so it's, it,
00:25:20 --> 00:25:23 it basically is new, ah, research.
00:25:23 --> 00:25:25 And so, so they can see two. They can
00:25:25 --> 00:25:27 detect that there are two objects
00:25:28 --> 00:25:29 orbiting one another.
00:25:30 --> 00:25:31 Andrew Dunkley: I sent the but.
00:25:32 --> 00:25:35 Professor Fred Watson: The butt is. Yes, yes. the
00:25:35 --> 00:25:37 but is that it looks as though one of them is
00:25:37 --> 00:25:40 actually a pair of objects. That's the trick.
00:25:41 --> 00:25:44 So we've got two things that have been
00:25:44 --> 00:25:46 seen, but one of them is
00:25:46 --> 00:25:49 probably a double. And they've had to
00:25:49 --> 00:25:52 use the very detailed,
00:25:52 --> 00:25:54 measurements of the way
00:25:55 --> 00:25:58 the object that they can see orbits the other
00:25:58 --> 00:26:00 one, the way that orbit changes.
00:26:01 --> 00:26:03 that is what tells you that the
00:26:04 --> 00:26:06 central object, if I can put it that way,
00:26:06 --> 00:26:09 might actually be two. and so it's
00:26:09 --> 00:26:11 the outer object, its orbit
00:26:11 --> 00:26:14 changes over time. And it's that change,
00:26:15 --> 00:26:18 that allows the deduction that the central
00:26:18 --> 00:26:21 object, if I put it that way, is.
00:26:23 --> 00:26:25 Well, they say it's either extremely
00:26:25 --> 00:26:28 elongated or it's two separate objects.
00:26:29 --> 00:26:31 And that, you know, the odds are that it is
00:26:31 --> 00:26:34 actually probably two. often though,
00:26:34 --> 00:26:36 we've got this situation, especially with
00:26:36 --> 00:26:39 these distant, asteroids,
00:26:40 --> 00:26:43 where you have clearly something that
00:26:43 --> 00:26:46 has been a binary, two objects in orbit
00:26:46 --> 00:26:47 around one another, but they've gradually,
00:26:48 --> 00:26:51 collapsed together, not in a violent way,
00:26:51 --> 00:26:54 and wound up in contact, which is something
00:26:54 --> 00:26:56 we call, believe it or not, a contact binary.
00:26:56 --> 00:26:59 And Arrokoth, it's one of the Kuiper Belt
00:26:59 --> 00:27:02 objects that you actually just referred to.
00:27:02 --> 00:27:04 It's beyond the orbit of Pluto. It was
00:27:04 --> 00:27:06 visited by New Horizons. when we saw it, it
00:27:06 --> 00:27:08 looked like a snowman. And that was very
00:27:08 --> 00:27:10 seasonal because I think it was Christmas
00:27:10 --> 00:27:13 time, when it was discovered. But the
00:27:13 --> 00:27:16 analysis of, New Horizons data as it
00:27:16 --> 00:27:18 flew past Arrokoth showed that it wasn't
00:27:18 --> 00:27:20 actually two balls joined together. It was
00:27:20 --> 00:27:22 two pancakes joined together, rim to rim,
00:27:23 --> 00:27:25 so that it actually looked like a snowman,
00:27:25 --> 00:27:27 but from the edge on, it looked a lot more
00:27:27 --> 00:27:30 like two pancakes stuck together. But that's
00:27:30 --> 00:27:32 a common phenomenon. Two objects, whatever
00:27:32 --> 00:27:34 their shape, is coming together gently and
00:27:34 --> 00:27:37 actually, basically cementing
00:27:37 --> 00:27:39 themselves together just by gravity. But then
00:27:39 --> 00:27:42 the sort of gap between them fills in and you
00:27:42 --> 00:27:43 end up with something that looks like a
00:27:43 --> 00:27:46 peanut. So I think it's still possible
00:27:47 --> 00:27:50 that Algeria could have that sort
00:27:50 --> 00:27:53 of shape. But they actually say,
00:27:53 --> 00:27:55 the research team who's done this, they say
00:27:56 --> 00:27:59 that the triple system actually fits the data
00:27:59 --> 00:28:01 best. it fits it better
00:28:02 --> 00:28:05 than a contact binary or a really elongated
00:28:05 --> 00:28:08 central object. So a triple system is what we
00:28:08 --> 00:28:11 Believe it is, it's a very nice target for
00:28:11 --> 00:28:13 a future mission to the outer solar system,
00:28:13 --> 00:28:15 but that's not going to happen anytime soon.
00:28:16 --> 00:28:18 but, yeah, so, very nice discovery. Triple
00:28:18 --> 00:28:21 systems are rare. That's why, that's why it,
00:28:21 --> 00:28:23 you know, it's making the headlines. These
00:28:23 --> 00:28:26 are rare phenomena. Binaries are very common.
00:28:27 --> 00:28:29 In fact, probably most objects out there in
00:28:29 --> 00:28:31 this outer solar system might be binaries,
00:28:31 --> 00:28:32 but triple systems are rare.
00:28:33 --> 00:28:36 Andrew Dunkley: interestingly, this, rock, if you want to
00:28:36 --> 00:28:39 call it that, or system Algeria,
00:28:39 --> 00:28:41 is much, much bigger than Arrokoth. it's,
00:28:42 --> 00:28:44 about 124 miles wide, or 200
00:28:44 --> 00:28:46 kilometres. That's a big chunk.
00:28:47 --> 00:28:49 Professor Fred Watson: Yes, it is, yes. A lot, more substantial than
00:28:49 --> 00:28:51 Arrokoth, which was only, if I remember
00:28:51 --> 00:28:52 right, it was less than a kilometre, I think.
00:28:53 --> 00:28:55 it's amazing that they found it at all. To
00:28:56 --> 00:28:59 give New Horizons a target beyond, Pluto.
00:29:00 --> 00:29:02 Andrew Dunkley: Yeah, yeah, as you say, we're probably not
00:29:02 --> 00:29:04 going to go back out there in a hurry. These
00:29:04 --> 00:29:07 missions are very long winded
00:29:07 --> 00:29:09 because of the distances involved. We're
00:29:09 --> 00:29:12 talking what, 30 or 30
00:29:12 --> 00:29:14 AU or something?
00:29:14 --> 00:29:16 Professor Fred Watson: Yeah, I think this is more, I think it's more
00:29:16 --> 00:29:18 like 45 AU or something like that. So it's.
00:29:18 --> 00:29:21 Yeah, AU is an astronomical unit,
00:29:21 --> 00:29:23 150 million kilometres.
00:29:23 --> 00:29:25 Andrew Dunkley: Yeah, that's a long way away. but
00:29:26 --> 00:29:29 yeah, it's probably an area of our
00:29:29 --> 00:29:31 solar system, even though it's so remote,
00:29:31 --> 00:29:34 that we need to learn more about because, you
00:29:34 --> 00:29:36 know, some of these rocks get
00:29:36 --> 00:29:38 bumped and end up heading our way.
00:29:39 --> 00:29:42 Professor Fred Watson: yes, that's right, they do, or, you know,
00:29:42 --> 00:29:44 gravitationally interact with other objects.
00:29:44 --> 00:29:47 but you're right, in some
00:29:47 --> 00:29:49 ways it's the last frontier. It's completing
00:29:49 --> 00:29:52 the evidence for the way we think. Our
00:29:52 --> 00:29:55 solar system formed by this icy,
00:29:55 --> 00:29:58 dust and gas cloud that collapsed. And a
00:29:58 --> 00:30:01 lot of this stuff is the last vestiges, the
00:30:01 --> 00:30:03 outer, the outer vestiges of those,
00:30:04 --> 00:30:06 you know, those, objects that eventually went
00:30:06 --> 00:30:08 up to make the inner planets. These are,
00:30:08 --> 00:30:10 these are worlds that have never been heated.
00:30:10 --> 00:30:12 And that's the, you know, the planets have
00:30:12 --> 00:30:15 been, they've been bombarded by gravitational
00:30:16 --> 00:30:19 interactions by collisions and, impacts
00:30:19 --> 00:30:20 and things of that sort, so that they're hot.
00:30:21 --> 00:30:23 these worlds have always been cold and that's
00:30:23 --> 00:30:25 why they're so interesting, because they're
00:30:25 --> 00:30:27 sort of the fossil of the solar system's
00:30:27 --> 00:30:28 earliest history.
00:30:28 --> 00:30:29 Andrew Dunkley: Yeah. Yeah.
00:30:29 --> 00:30:31 Well, I guess the time will come where we do
00:30:31 --> 00:30:33 extensive studies, but, I think we'll have to
00:30:33 --> 00:30:36 get better spacecraft and maybe use
00:30:36 --> 00:30:38 those, superhighways you were talking about.
00:30:38 --> 00:30:39 Professor Fred Watson: Yeah, yeah, that's right.
00:30:39 --> 00:30:41 Andrew Dunkley: Get out there and have a look.
00:30:41 --> 00:30:41 Professor Fred Watson: Yes.
00:30:41 --> 00:30:43 Andrew Dunkley: if you'd like to read up on that, you can do
00:30:43 --> 00:30:46 that at the NASA science website or you can
00:30:46 --> 00:30:49 go, to the study itself, which was published
00:30:49 --> 00:30:51 in the Planetary Science Journal.
00:30:52 --> 00:30:54 that brings us to the end. Fred, thank you so
00:30:54 --> 00:30:54 much.
00:30:55 --> 00:30:57 Professor Fred Watson: it's a pleasure, Andrew. a nice surprise to
00:30:57 --> 00:30:59 see you and, always a pleasure to talk.
00:31:00 --> 00:31:02 Andrew Dunkley: Good to see you too. And we'll catch you on
00:31:02 --> 00:31:04 the very next episode. Don't forget to visit
00:31:04 --> 00:31:06 us online. In the meantime, we've got, plenty
00:31:06 --> 00:31:09 of platforms. We're on Instagram, we're on
00:31:09 --> 00:31:11 YouTube, we're on Facebook, we're on our
00:31:11 --> 00:31:13 own website, spacenutspodcast.com
00:31:14 --> 00:31:16 SpaceNuts IO Either URL will
00:31:16 --> 00:31:19 take you to the same place and have a look
00:31:19 --> 00:31:22 around while you're there. And, Huw in
00:31:22 --> 00:31:24 the studio, he did actually turn up briefly
00:31:24 --> 00:31:26 today, but he forgot to put on his kuiper
00:31:26 --> 00:31:28 belt and his pants fell down, so he had to
00:31:28 --> 00:31:31 make a run for it from me, Andrew
00:31:31 --> 00:31:34 Dunkley. Oh, it's terrible. Thanks, for your
00:31:34 --> 00:31:36 company. We'll see you on the next episode of
00:31:36 --> 00:31:36 Space Nuts.
00:31:36 --> 00:31:37 Professor Fred Watson: Bye. Bye.
00:31:38 --> 00:31:40 Voice Over Guy: You've been listening to the Space Nuts
00:31:40 --> 00:31:43 podcast, available at
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00:31:45 --> 00:31:48 iHeartRadio or your favourite podcast
00:31:48 --> 00:31:50 player. You can also stream on
00:31:50 --> 00:31:53 demand at bitesz.com This has been another
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