Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / The Pink, Salty Exoplanet — Could Humanity Travel to the Galaxy’s Most Colorful World?

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The Pink, Salty Exoplanet — Could Humanity Travel to the Galaxy’s Most Colorful World? · Space Nuts: Astronomy Insights & Cosmic Discoveries

• 0:00
  Andrew Dunkley: Hi there. Thanks for joining us yet again for
• 0:02
  another episode of Space Nuts where we talk
• 0:05
  astronomy and space science. My name is
• 0:07
  Andrew Dunkley. Hope you're well. Thanks for
• 0:09
  your company. Today we're going to try and
• 0:11
  understand the Martian
• 0:14
  moon of Phobos. Um,
• 0:17
  was it born of a collision like our moon, or
• 0:20
  was it captured? And what's going on
• 0:23
  inside might be the only way to find out what
• 0:25
  it really is. Uh, we're also going to look at
• 0:28
  an exoplanet that my wife would adore. My
• 0:30
  wife loves salt. Like, you know, you give her
• 0:33
  a glass of ocean water and she says, can you
• 0:35
  put salt in that, please? Uh, this, this
• 0:37
  is, I'm not joking. This is
• 0:40
  an extraordinary planet and we'll tell you
• 0:42
  why. And uh, a very swift
• 0:45
  mission to save a vital space observatory.
• 0:48
  That'll make sense when we explain it all on
• 0:50
  this episode of, ah, space nuts.
• 0:52
  Andrew Dunkley: 15 seconds. Guidance is internal.
• 0:55
  10, 9. Ignition
• 0:58
  sequence start.
• 0:59
  Professor Fred Watson: Space nuts.
• 1:00
  Andrew Dunkley: 5, 4, 3, 2, 1. 2,
• 1:03
  5, 5, 4, 3, 2,.
• 1:05
  Andrew Dunkley: Space nuts.
• 1:06
  Andrew Dunkley: Astronauts report it feels good.
• 1:09
  Andrew Dunkley: And with us once more is Professor
• 1:11
  Fred Watson Watson, astronomer at large.
• 1:12
  Hello Fred Watson.
• 1:13
  Professor Fred Watson: Hello, Andrew. Hello. Nice to see you again.
• 1:16
  Yes, you too.
• 1:19
  Andrew Dunkley: We could do the whole show just
• 1:20
  Professor Fred Watson: talking rubbish like that.
• 1:23
  Andrew Dunkley: Well, we do that anyway.
• 1:24
  Professor Fred Watson: Uh, yes, I've forgotten that.
• 1:28
  Andrew Dunkley: Indeed.
• 1:30
  Andrew Dunkley: We got some really interesting storeys.
• 1:32
  Um, I mean Mars always fascinate
• 1:35
  me but uh, the moon Phobos in particular.
• 1:39
  Uh, and we've got a salty atmosphere in an
• 1:41
  exoplanet which um, I uh, haven't told my
• 1:44
  wife about because she'd probably want to go
• 1:45
  there and uh, um, a
• 1:48
  mission that's got to get off the ground
• 1:50
  ultra quick to save an
• 1:52
  observatory in space. I really, really
• 1:55
  am looking forward to that storey.
• 1:57
  But, um, let's uh, turn our attention to
• 2:00
  the Martian moon of Phobos.
• 2:03
  Uh, I did a little bit of research and it
• 2:06
  is apparent the um,
• 2:09
  closest orbiting moon of
• 2:12
  any planet in our solar system to its parent
• 2:15
  planet.
• 2:16
  Professor Fred Watson: That's not a surprise.
• 2:19
  Andrew Dunkley: Six thousand kilometres from the surface.
• 2:21
  Professor Fred Watson: Yeah, uh, in fact
• 2:24
  it's got this peculiar aspect
• 2:28
  uh, that uh, it
• 2:31
  orbits Mars. Of course, being a moon of
• 2:33
  Mars, it's the bigger of the two moons of
• 2:36
  Mars. It's only 23 kilometres across. So it's
• 2:38
  not really what you call a big moon. Uh, but
• 2:41
  it's got this extraordinary thing that it
• 2:43
  goes around Mars once in 7 hours and 39
• 2:46
  minutes. But Mars
• 2:49
  takes 24 hours and 40 minutes to rotate
• 2:51
  once on its axis. So this moon
• 2:54
  in Mars sky goes backwards.
• 2:57
  Um, its Own motion
• 3:00
  is enough to overcome the
• 3:03
  rotational motion of the
• 3:06
  planet. So, uh, yes, it goes
• 3:09
  more or less goes around twice a day. Uh, in
• 3:12
  fact, getting on for three times a day. Um,
• 3:16
  in fact, more than three times a day.
• 3:19
  My arithmetic's not very good at the moment.
• 3:22
  Um, so, yeah, uh, it's,
• 3:25
  uh, quite remarkable that you've got this
• 3:28
  phenomenon. So a, uh, very unusual
• 3:31
  moon. It's been known since, I think it was
• 3:34
  the 1880s. Um, uh, it
• 3:36
  was discovered, uh,
• 3:39
  actually by somebody who was related. There's
• 3:42
  a curious link. There's an uncle of
• 3:45
  Venetia Burney. Who you might remember was
• 3:48
  the young woman at the age of 11, I think,
• 3:50
  who gave Pluto its name.
• 3:52
  Andrew Dunkley: Oh, yeah.
• 3:52
  Professor Fred Watson: And she was in Oxford. And her uncle
• 3:55
  discovered, uh, the two moons of Mars. Very
• 3:58
  small objects, as I've said. Since that time,
• 4:01
  everybody's wondered how they got there. Uh,
• 4:04
  partly because they are small enough
• 4:07
  that it's
• 4:10
  possible they've got multiple different
• 4:12
  origins. Not simultaneously, but
• 4:15
  they've originated in, uh, a variety of ways.
• 4:18
  That's the possibility. Uh, so the two
• 4:20
  theories, um, one is. Well, more
• 4:23
  or less what you've alluded to already. One
• 4:26
  is that there was an event similar to the
• 4:29
  event that created our own moon. A collision
• 4:31
  in the early solar system by Mars
• 4:34
  with another, smaller object that sort of
• 4:37
  bashed into it, uh, lifted a whole lot of
• 4:39
  debris which coalesced to form the
• 4:42
  orbital. To form the object, uh,
• 4:45
  Phobos. And the other theory is that it's a
• 4:47
  captured asteroid. And I guess in the case of
• 4:49
  Mars, that's got some attractions to it.
• 4:52
  Because, uh, Mars, of
• 4:55
  course, is right on the inner edge of the
• 4:58
  main asteroid belt. So not very far from
• 5:00
  Mars. There are lots and lots of asteroids
• 5:02
  lurking. And we know from the way
• 5:04
  Jupiter's great gravitational pull Tinkers
• 5:07
  around with that asteroid belt, uh, that once
• 5:10
  in a while they stray from the main belt and
• 5:13
  you might get a capture. Um, it's
• 5:15
  also been known for a long time to have
• 5:19
  a peculiar composition. Its density
• 5:22
  is very low. And the suspicion is that it's
• 5:24
  made of something a bit like pumice. Um, you
• 5:28
  remember pumice being the
• 5:30
  material that, uh, is formed when
• 5:33
  volcanoes erupt underneath the ocean. You
• 5:36
  get this aerated stuff, almost like a
• 5:39
  foam. Um, and so its density
• 5:42
  is low enough that people don't really know
• 5:45
  whether that's what its interiors like.
• 5:48
  Uh, and of course, the other possibility,
• 5:50
  when you've got something with a low density
• 5:52
  like that, um, in common with many asteroids,
• 5:55
  is that it could be a rubber pile in
• 5:58
  other words something that's just made of
• 6:00
  loosely bound material all sort of stuck
• 6:03
  together by its own gravity, very feeble
• 6:05
  gravity because it's very small. Um, I have
• 6:08
  to say, um, Phobos doesn't look like that. It
• 6:10
  does look like a more solid object and it's
• 6:13
  got surface features including several quite
• 6:16
  big craters and one very big crater, uh,
• 6:18
  which is called Stickney. Um, I think
• 6:21
  it's about seven kilometres across and in an
• 6:24
  object that's only 22 and a half kilometres
• 6:27
  across. 22.2 actually. Um,
• 6:30
  that is a big crater.
• 6:33
  So all these factoids come together to make
• 6:36
  us wonder how it got there, what it's made
• 6:39
  of. Uh, and just one other comment about
• 6:42
  its orbit. Um, its orbit around
• 6:45
  Mars is not stable, uh, over a uh,
• 6:48
  long enough period of time and I think we're
• 6:50
  talking a few million years perhaps it
• 6:53
  will probably collide with Mars
• 6:56
  or just be pulled to pieces
• 6:58
  because it will get within the Roche limit of
• 7:01
  Mars. That's the, the limit within which a
• 7:04
  solid object can't exist or
• 7:07
  a solid object of any given size can't exist
• 7:09
  because of the gravitational disturbance.
• 7:11
  We've talked about Roche limits before I
• 7:13
  Andrew Dunkley: think and, and if it's, if it is pumice
• 7:16
  like. Yeah, there's every chance it will
• 7:18
  sort of crumble in the, in the sky.
• 7:21
  Professor Fred Watson: Yes, that's right. Uh, not, you know,
• 7:24
  not a uh, not a
• 7:27
  solid object that would resist uh,
• 7:29
  gravity. Tidal forces is technically what
• 7:32
  they are. Tidal forces are when one end of an
• 7:34
  object feel a different gravitational pull
• 7:36
  from the other end. Uh, and so um, yes,
• 7:39
  tidal forces would perhaps deal
• 7:41
  the final blow. Um,
• 7:44
  but yes, so studies looking
• 7:47
  at what uh, Phobos is
• 7:50
  made of and I guess these are coming out and
• 7:53
  the interest is growing in
• 7:56
  advance of um, an upcoming space
• 7:58
  mission which is being launched by the
• 8:01
  Japanese uh, Aerospace
• 8:03
  Exploration Agency jaxa. Uh,
• 8:06
  it is called the Martian Moons
• 8:09
  Exploration. Uh, it's uh,
• 8:12
  otherwise known as MMX and it is a
• 8:14
  Phobos sample return mission. So
• 8:18
  clearly this mission is expecting to land
• 8:21
  on the surface of Phobos. Uh, it will
• 8:23
  launch later this year and it will.
• 8:27
  What the pundits uh are saying is it will
• 8:29
  attempt a quasi stable orbit around the
• 8:32
  tiny moon. This is a difficult task because
• 8:35
  there is truly no stable orbit around Phobos
• 8:38
  and the reason for that is that you've got
• 8:41
  this thing with such weak gravity that
• 8:43
  getting something into orbit around it will
• 8:45
  be a challenge in the first place. But right
• 8:47
  next to it, 6,000 kilometres away, as you've
• 8:50
  said, is a large planet, um, not a
• 8:53
  large planet by planetary standards, but a
• 8:55
  large by the standards of Phobos.
• 8:58
  So lots uh, of challenges there and I think
• 9:01
  um, hopefully it'll be something we will
• 9:02
  cover uh, over the next couple of years or so
• 9:05
  to find out what is happening with
• 9:08
  Phobos.
• 9:09
  Andrew Dunkley: And I understand that to try and figure out
• 9:12
  how it became Phobos. Is
• 9:15
  everything to do with what's happening inside
• 9:17
  Phobos?
• 9:18
  Professor Fred Watson: That's right, yes. Um,
• 9:21
  there's one. So there's a
• 9:24
  suggestion that it may actually have
• 9:26
  a large ice content, um, as well
• 9:29
  as rock, uh, but we just don't
• 9:32
  know about that. There's also, I think uh,
• 9:35
  there is suggestion too that
• 9:38
  um, there's
• 9:41
  a higher density region
• 9:43
  underneath this crater. Ah, Stickney. And
• 9:46
  you can sort of imagine that would be the
• 9:49
  case if you've got something um, which
• 9:52
  is like a piece of pumice or a kind
• 9:55
  of sponge like structure, you get a large
• 9:58
  ish object clouting the surface, which is
• 10:01
  probably what caused Stickney. You're going
• 10:03
  to get some compression, what you might call
• 10:05
  a localised zone of densified
• 10:08
  material. As the authors of this paper,
• 10:11
  uh, which has appeared in the monthly notices
• 10:13
  of the Royal Astronomical Society.
• 10:15
  Andrew Dunkley: Yeah, well, when you look at the close up
• 10:17
  image that came from NASA jpl,
• 10:20
  uh, yeah, it doesn't look,
• 10:24
  I don't know how you'd describe it. Uh, I
• 10:27
  mean it's got a potato shape about it but
• 10:31
  it almost looks metallic in some respects.
• 10:33
  Professor Fred Watson: It does, that's correct. It's got. And
• 10:37
  I guess what you're looking at is kind of the
• 10:38
  same things that I see when I look at it. And
• 10:40
  that is craters with relatively sharp
• 10:43
  edges to them on the scale that we can
• 10:46
  see. And you know, that doesn't sound like
• 10:48
  something made of pumice. Um, if you've got
• 10:51
  uh, craters that have got well defined edges.
• 10:53
  So many mysteries, um, we came close
• 10:56
  to knowing more
• 10:59
  quite a few years ago. It's probably a decade
• 11:01
  ago now. Do you remember Phobos Grunt? Uh,
• 11:04
  yes. Which was a Russian
• 11:06
  spacecraft, uh, that was uh,
• 11:09
  going to go to Phobos and bring back a
• 11:12
  sample. Uh, Phobos Grunt. Grunt
• 11:14
  is effectively the Russian word for ground
• 11:17
  or you know, landing on the surface.
• 11:20
  Um, and uh, it failed
• 11:23
  because it got into orbit. But the
• 11:26
  spacecraft that was going to push it in the
• 11:28
  transfer orbit to Mars didn't work.
• 11:31
  And so eventually it just re. Entered back
• 11:34
  into the Earth's atmosphere. It was very sad.
• 11:36
  Um, it was um, uh, you know, a
• 11:39
  mission which we, we expected
• 11:42
  great things from.
• 11:43
  Andrew Dunkley: So maybe, um, the engines didn't fire
• 11:45
  properly.
• 11:46
  Professor Fred Watson: I think that was right. Yes. Yeah, that's
• 11:47
  right.
• 11:48
  Andrew Dunkley: And, uh, it. It just got stuck in low Earth
• 11:50
  orbit and that was the end of that.
• 11:51
  Professor Fred Watson: Yep.
• 11:52
  Andrew Dunkley: Yeah, it happens. It happens.
• 11:54
  Professor Fred Watson: It does. We hope it won't happen with mmx,
• 11:56
  the, The Japanese mission.
• 11:58
  Andrew Dunkley: No, no. Um, I. Yeah, well,
• 12:01
  you can never say never, but, um, hopefully
• 12:03
  it will be very successful and we will learn
• 12:05
  more about Phobos and what makes it tick.
• 12:08
  Which way do you lean? Solid object that got
• 12:11
  captured or a collision
• 12:14
  type of event?
• 12:15
  Professor Fred Watson: I didn't know it ticked. Anyway, never mind.
• 12:19
  Andrew Dunkley: I hope not.
• 12:20
  Professor Fred Watson: I do too. Um, I think
• 12:23
  it might be a captured asteroid. That will be
• 12:25
  my view. Um, it's
• 12:28
  got sort of characteristics of asteroids
• 12:31
  that. That makes me think maybe
• 12:34
  it is basically just something that
• 12:37
  wandered too close to Mars and got captured.
• 12:41
  Andrew Dunkley: Yeah, I'm leaning that way too, but only
• 12:44
  because it seems more logical. I have no
• 12:47
  scientific backup to my claim, but, um,
• 12:50
  anyway, neither do I, really.
• 12:54
  It's, ah, interesting, Storey. You can read
• 12:56
  about it in the monthly Notices of the Royal,
• 12:59
  uh, Astronomical Society, as Fred Watson
• 13:01
  said, or you can go to universetoday.com,
• 13:04
  this is space Nuts, the podcast about
• 13:07
  astronomy and space science.
• 13:13
  Space Nuts and Fred Watson.
• 13:15
  We're going a little bit further away than
• 13:17
  Mars. We're heading 50, uh, seven light
• 13:20
  years away to, uh, an exoplanet. Uh, it's
• 13:23
  called GJ 504B.
• 13:26
  Uh, this planet has got a couple of really
• 13:29
  amazing characteristics. Um, one
• 13:32
  being it is pink.
• 13:34
  And the second being its atmosphere
• 13:37
  seems to be very, very salty. In fact, it
• 13:40
  could be the Himalayan
• 13:43
  salt planet, you just never know.
• 13:45
  Himalayan pink salt, very, very popular.
• 13:49
  Um, it's a very strange one
• 13:51
  and my wife would love to go there because,
• 13:55
  uh, as I've said, she really adores salt. You
• 13:57
  give her a steak, put salt on it, give her,
• 13:59
  um, um, vegetables, put salt on it.
• 14:02
  Andrew Dunkley: It.
• 14:02
  Andrew Dunkley: Ice cream, put more salt on it. Yeah,
• 14:05
  she loves her salt. Um, now
• 14:09
  I'm going to suffer a salt and battery if I
• 14:11
  keep talking about it like that.
• 14:14
  Tell us about this unusual pink planet.
• 14:16
  Professor Fred Watson: Yeah, I'm glad you did the Himalayan
• 14:19
  salt thing, because if you hadn't,
• 14:22
  I would have done. Yeah, that's
• 14:25
  right. I don't know that the two are
• 14:26
  necessarily related. So, uh, it's, you know,
• 14:29
  there's quite a backstory with this. This is
• 14:31
  a planet, um, an exoplanet
• 14:35
  that is unusual in that we see it directly,
• 14:37
  as you and I have said many times.
• 14:40
  Uh most exoplanets we only infer their
• 14:43
  presence from the behaviour of their
• 14:45
  parent star. With this one we can
• 14:48
  actually see it which is how we know it's
• 14:50
  pink. Um, we've known about
• 14:53
  it for 13 years, discovered back in 2013.
• 14:57
  Uh but it's also a little
• 15:00
  bit um, of an enigma
• 15:03
  because its mass
• 15:06
  is about 25 times
• 15:09
  that of Jupiter.
• 15:10
  Andrew Dunkley: Yeah, uh, well salt's not light.
• 15:17
  Professor Fred Watson: Well notwithstanding the salt we might get
• 15:19
  back to that in a minute
• 15:23
  to some other salty tales. Um,
• 15:27
  the thing is that if this
• 15:30
  object were ah just on its own in space
• 15:32
  rather than in orbit around another
• 15:35
  world, we wouldn't call it a planet, we'd
• 15:38
  call it a brown dwarf star. Because
• 15:41
  the um, criterion for
• 15:45
  an object to be a brown dwarf star
• 15:48
  is a mass more than 13 times that of
• 15:51
  Jupiter because that's the mass
• 15:54
  at uh, which some low level nuclear
• 15:56
  reactions switch on that distinguish it, I
• 15:59
  think it's deuterium burning is the technical
• 16:02
  term, distinguish it as a star
• 16:05
  rather than a planet. Uh and so I think the
• 16:08
  only reason it's being called a planet is
• 16:09
  because it's going around uh, another star.
• 16:12
  You could in fact almost say it's actually
• 16:15
  a double star. Uh but people
• 16:18
  don't seem to be saying that. I think it's
• 16:20
  because that 13 Jupiter masses is
• 16:23
  a fairly blurry ah sort of
• 16:26
  boundary for an object to be
• 16:29
  classified as a brown dwarf.
• 16:32
  Anyway, um, brown dwarfs are
• 16:35
  well known, well studied. They are this sort
• 16:38
  of interim phase where you've got low level
• 16:41
  nuclear processes, you don't have the nuclear
• 16:44
  fusion that uh, characterises a
• 16:46
  genuine star. Um,
• 16:49
  so um,
• 16:53
  I've just noted a sentence in this
• 16:56
  very nice article about this from the science
• 16:58
  blog, um, which uh,
• 17:00
  puts it perfectly, it sums up just what I've
• 17:03
  said. Uh, it says uh,
• 17:05
  astronomers hedge their bets and call it a
• 17:08
  planetary mass companion and that
• 17:11
  gets over the problem. It's a planetary mass
• 17:13
  companion rather than a planet and
• 17:16
  not necessarily a star. So there you go,
• 17:20
  Andrew Dunkley: to quote Monty Pothon, you're just making
• 17:22
  that up.
• 17:26
  Professor Fred Watson: We make it all up and trim, you know that but
• 17:28
  they don't. You're right, they don't know
• 17:30
  that. So um,
• 17:34
  also interesting uh, because it's
• 17:37
  cool so you know the most of the,
• 17:40
  and I mean cool in a temperature sense rather
• 17:43
  than um, its presence on social media.
• 17:46
  Uh, uh, most of these
• 17:49
  objects like brown dwarf stars are well over
• 17:52
  a thousand degrees Celsius. Um, this
• 17:55
  one is only 290
• 17:58
  degrees Celsius. Uh and once
• 18:01
  again going back to that um,
• 18:04
  science blog article, they've said
• 18:07
  that's about the temperature of an oven
• 18:09
  baking bread, um, which
• 18:12
  is, um, worn by terrestrial standards, but
• 18:15
  not by space standards. And so we've got this
• 18:18
  object, which is a mystery, uh, but
• 18:21
  the reason it's in the news is because,
• 18:24
  uh, there have been studies
• 18:27
  with the James Webb Telescope. Apparently
• 18:30
  this object has been studied a great deal
• 18:34
  in the 13 years that we've known about it.
• 18:36
  Um, but it's some observations now made
• 18:39
  with the James Webb Space Telescope, which
• 18:41
  continues to amaze us because of its
• 18:43
  capabilities. Um, and the
• 18:46
  spectrum,
• 18:48
  uh, of its atmosphere,
• 18:51
  of course, reveals these different spectral
• 18:54
  fingerprints. We talk about that a lot and
• 18:56
  space nuts. And it's what I used to do for a
• 18:58
  living. Uh, the spectral fingerprints of
• 19:01
  stars and galaxies. Uh, anyway, um,
• 19:04
  observations with this revealed a
• 19:07
  spectrum that was very difficult to
• 19:09
  understand, uh, because it had
• 19:12
  features that didn't seem to make
• 19:14
  any sense. Uh, and
• 19:18
  it turns out that the trick was
• 19:21
  to look at different
• 19:24
  sorts of clouds that you might have in the
• 19:26
  atmosphere rather than just a clear
• 19:28
  atmosphere. And it was when they
• 19:31
  basically tried to fit the spectra that would
• 19:34
  be produced by different types of clouds, uh,
• 19:37
  to what they were observing with the Webb
• 19:38
  Telescope, uh, that these, uh,
• 19:41
  authors, uh, who've done this research
• 19:44
  found that the best fit was salt clouds.
• 19:47
  And now I find it hard to imagine whether
• 19:50
  those are clouds of salt, of pure salt, uh,
• 19:53
  in a solid form, um, or
• 19:56
  whether it's not salt vapour.
• 20:00
  I don't think, um, because at, uh,
• 20:02
  temperature, um, it's likely
• 20:04
  to be solid salt.
• 20:07
  Andrew Dunkley: Wow, that's. Wow.
• 20:10
  I'm gonna show this to my wife. She'll be
• 20:12
  very, very excited.
• 20:13
  Professor Fred Watson: It's drifting. It's drifting in the air.
• 20:16
  Andrew Dunkley: Uh, so I could go out there now and say, you
• 20:18
  know, with. They've found planets that are
• 20:19
  made of diamond.
• 20:20
  Professor Fred Watson: Yes.
• 20:21
  Andrew Dunkley: And they found one made of salt. She said
• 20:22
  we're going there.
• 20:23
  Professor Fred Watson: Yeah,
• 20:26
  yeah, there you go.
• 20:28
  Andrew Dunkley: I'm taking, I'm taking the mickey. But, yeah,
• 20:30
  anyway, uh, it, uh.
• 20:33
  I just thought of something which I probably
• 20:36
  should have said at the time, but it can't be
• 20:37
  a brown dwarf. It's got to be a planet.
• 20:39
  Andrew Dunkley: It.
• 20:39
  Andrew Dunkley: Because it's not the right colour.
• 20:43
  Professor Fred Watson: Yes. Being pink. It is not brown. Is. It
• 20:46
  could be a new.
• 20:47
  Andrew Dunkley: Could be. We could have discovered a pink
• 20:49
  dwarf.
• 20:50
  Professor Fred Watson: Yeah, well, maybe that's what it's going to
• 20:52
  be classified as. Because, you know, the, the
• 20:54
  colour itself must, must relate to,
• 20:57
  to what it looks like. To the, to the.
• 21:00
  Sorry, that's a tautology.
• 21:04
  Uh, the colour relates to the
• 21:06
  constituents of its clouds. That's what I
• 21:08
  meant to say, really. Yeah.
• 21:10
  Andrew Dunkley: Well, when you look at Jupiter, I mean, it's
• 21:12
  in the red spectrum too, isn't it, really?
• 21:15
  Professor Fred Watson: Yes, it is. It's got. Yeah. I mean, um,
• 21:18
  and Saturn as well. They've got colours that
• 21:20
  really, uh. In a sense, they're what we might
• 21:23
  describe as warmer colours. Although that
• 21:26
  doesn't. The temperature goes the other way.
• 21:28
  The warmth of the colour relates to something
• 21:30
  called the colour temperature. And the higher
• 21:33
  the colour temperature, the more white, um,
• 21:36
  and brilliant objects are, whether they're
• 21:38
  stars or lumps of metal or whatever.
• 21:41
  Andrew Dunkley: Um.
• 21:41
  Professor Fred Watson: But yes. So a pink one.
• 21:44
  The pink in a way matches
• 21:47
  the low temperature of this because
• 21:50
  anything that's glowing, um,
• 21:53
  would have colours that would characterise
• 21:55
  what its temperature is. So,
• 21:58
  um, I think we've solved one mystery there,
• 22:00
  Andrew.
• 22:01
  Andrew Dunkley: Maybe so. Yes. I knew we'd get somewhere
• 22:03
  sooner or later. We always endeavour to
• 22:07
  adequately deal with these issues.
• 22:10
  Yeah. Um, but no, it's a really fascinating
• 22:13
  planet and, um, well worth reading that,
• 22:16
  Storey.
• 22:17
  It's cool. It's pink. It's salty.
• 22:20
  I mean, that sounds very provocative.
• 22:23
  Professor Fred Watson: Uh, actually, it sounds like
• 22:26
  Scottish porridge.
• 22:28
  Andrew Dunkley: I've had that. I had that last year when we
• 22:30
  went to Edinburgh. I loved it.
• 22:33
  Professor Fred Watson: It's very nice. Yeah. I had my porridge this
• 22:35
  morning, but I put honey in it.
• 22:37
  Andrew Dunkley: Sorry, just reminds m. Me. They, they. They,
• 22:39
  um. They have a drink called salt coffee
• 22:42
  in Vietnam.
• 22:43
  Professor Fred Watson: Okay.
• 22:44
  Andrew Dunkley: Which is. It's to die for, is it?
• 22:47
  It is, yeah. We got addicted to it. We had it
• 22:50
  every day while we were over there.
• 22:51
  Professor Fred Watson: Interesting.
• 22:52
  Andrew Dunkley: It is, really.
• 22:53
  Professor Fred Watson: Is it just coffee with salt in, or.
• 22:55
  Andrew Dunkley: No, it's. It's a. It's a shot of coffee, uh,
• 22:58
  then condensed milk and then cream
• 23:01
  salted. And they give it to you and it comes
• 23:03
  in three different layers and then you just
• 23:05
  stir it up and drink it. And we had it iced
• 23:08
  because it was so hot over there.
• 23:09
  Professor Fred Watson: Yeah.
• 23:10
  Andrew Dunkley: Uh, but you can have it hot as well. It's.
• 23:12
  It's delicious. Yes. And then you have
• 23:15
  a heart attack.
• 23:18
  Professor Fred Watson: Yeah. Which is less. Less delicious.
• 23:20
  Andrew Dunkley: Yeah, yeah, yeah. No, very nice. But, um,
• 23:23
  there you go. If you want to read about the
• 23:24
  salty exoplanet, you can do that at science
• 23:27
  blogs. This is Space Nuts with
• 23:30
  Andrew Dunkley and Professor Fred Watson
• 23:32
  Watson.
• 23:34
  Professor Fred Watson: I believe that this nation should commit
• 23:37
  itself to achieving the goal
• 23:39
  before this decade is out, of landing a
• 23:42
  man on the moon and returning him safely to
• 23:45
  the Earth.
• 23:47
  Andrew Dunkley: Our final storey. Uh,
• 23:50
  Fred Watson, is about a swift mission to save
• 23:53
  A vital space observatory. This. This storey
• 23:55
  I've seen popping up a few times in recent,
• 23:57
  um, days. And
• 24:00
  it's, um. Because of the timing issue
• 24:03
  they've got with this, uh, they've got to act
• 24:06
  very swiftly to save the Swift
• 24:09
  observatory.
• 24:10
  Professor Fred Watson: Um, that's right. It's a swift storey.
• 24:13
  Sorry, a storey we'll cover swiftly
• 24:17
  at the end of the show. Um, it is. It's
• 24:20
  a great storey. And what's making.
• 24:22
  Andrew Dunkley: For all the wrong reasons, it's a great
• 24:24
  storey.
• 24:24
  Professor Fred Watson: Yes, that's right. Uh, what's making the
• 24:26
  headlines is that,
• 24:30
  uh, engineers and scientists have been able
• 24:33
  to do what they do, what they've done. Uh,
• 24:36
  and in fact, the main, uh, proponent of
• 24:39
  this is a company that only started in 2020.
• 24:42
  Uh, and so it's, um. Uh,
• 24:45
  basically a response to NASA
• 24:48
  saying, help, we need help.
• 24:51
  Andrew Dunkley: Somebody pitch an idea to fix this problem.
• 24:53
  Professor Fred Watson: Yeah. And this company, Catalyst Space
• 24:55
  Technologies, did so. Uh, the background
• 24:58
  storey here is that Swift is a satel
• 25:01
  which has actually been in orbit, I think,
• 25:03
  since the early 2000s. I can't remember the
• 25:05
  exact year, but, uh, it's a,
• 25:08
  uh, venerable spacecraft. Uh,
• 25:11
  its job. Yeah.
• 25:14
  November 2004, that was
• 25:17
  when.
• 25:17
  Andrew Dunkley: 20th of, in fact.
• 25:19
  Professor Fred Watson: Indeed the 20th. Lots of twos there.
• 25:21
  Zeros. Um, and
• 25:24
  Swift, Uh, so it's a spacecraft that
• 25:27
  has basically proved its worth in a big way.
• 25:30
  And it's. Its, um, mission was
• 25:33
  and remains to detect gamma ray
• 25:36
  bursts. And these are, uh, bursts of gamma
• 25:39
  rays, as you'd expect, that we now know, come
• 25:41
  from probably colliding neutron
• 25:44
  stars, things of that sort, really energetic
• 25:47
  phenomena in deep space. Um,
• 25:50
  they themselves have an interesting history
• 25:52
  because gamma ray bursts were not known
• 25:54
  before the 1970s. And it was when,
• 25:58
  uh, various agencies launched
• 26:01
  spacecraft that could detect gamma rays,
• 26:04
  uh, in order not to look at the universe,
• 26:07
  but to look down on the Earth to make sure
• 26:09
  nobody was, uh, actually breaking the
• 26:12
  agreements of the nuclear test, uh,
• 26:15
  treaty, uh, and basically, um,
• 26:18
  doing nuclear testing in the atmosphere. That
• 26:21
  was what it was all about. It was to guard
• 26:22
  against, uh, maverick nuclear
• 26:25
  tests in the Earth's atmosphere. But it
• 26:28
  didn't discover any of those. But it did
• 26:29
  discover a whole new cosmic phenomenon. And
• 26:32
  the thing about gamma ray bursts is
• 26:35
  gamma rays itself don't tell you much
• 26:38
  about it except what
• 26:41
  direction this thing lies in. And
• 26:43
  so, uh, Swift, and its name is very well
• 26:46
  chosen, was a spacecraft that was designed to
• 26:49
  give swift measurements, uh, to
• 26:52
  the astronomical world so that they could
• 26:54
  very quickly turn their visible light
• 26:58
  and radio telescopes onto the place where
• 27:01
  this gamma ray burst had emitted and
• 27:03
  essentially sense an afterglow, what we
• 27:06
  call the optical counterpart in the case of
• 27:09
  visible light. And it's the optical
• 27:11
  counterpart that lets you do the
• 27:12
  astrophysics. It lets you make the
• 27:14
  measurements that you need to know how far
• 27:15
  away it is and what's been going on there.
• 27:18
  Uh, it's been a long time coming, our
• 27:21
  understanding of what's really going on with
• 27:23
  gamma ray bursts for a long time, they're a
• 27:25
  complete mystery. Anyway, Swift as a
• 27:28
  satellite has got fabulous track record,
• 27:31
  but it does not boast
• 27:34
  in its retinue, uh, of instruments, it
• 27:37
  doesn't boast any thrusters. Uh,
• 27:40
  and yeah, it does seem like in modern,
• 27:43
  you know, our modern understanding of the way
• 27:45
  you put a satellite into orbit. You want to
• 27:47
  have something that will actually let you
• 27:49
  shift its position or its height, even if
• 27:52
  it's only to get out of the way of the
• 27:53
  nearest Starlink spacecraft that's going to
• 27:55
  collide with it if you don't. So, um,
• 27:58
  it doesn't have thrusters. It would belong to
• 28:00
  an earlier E. And of course
• 28:03
  its initial orbit I think was
• 28:06
  um, something like
• 28:09
  uh, getting on for 600 kilometres. That was
• 28:12
  its early orbit, 585
• 28:14
  kilometres above Earth. But
• 28:17
  over the decades, uh, and there have been
• 28:20
  a couple of them, uh, that
• 28:23
  orbit has deteriorated because even at that
• 28:26
  height there is still
• 28:29
  a trace, excuse me, a trace of the Earth's
• 28:31
  atmosphere. And so
• 28:34
  that trace uh, of atmosphere is enough
• 28:37
  to break the spacecraft. B R A K E not B R
• 28:40
  E A K uh, which will slow it down
• 28:43
  and of course as you slow it down it
• 28:45
  descends and as it descends it hits more
• 28:47
  atmosphere which slows it down even more and
• 28:50
  then it descends even more. And you're on
• 28:52
  this pathway to ah, a re entry.
• 28:55
  Um, it's currently I uh, think,
• 28:58
  uh, flying at 363
• 29:01
  kilometres. So that's quite a long way down.
• 29:03
  Andrew Dunkley: That's a big deterioration in its orbit.
• 29:05
  Professor Fred Watson: It is, that's right. And that deterioration
• 29:08
  will not just continue, it will increase
• 29:11
  as it experiences a thicker atmosphere.
• 29:14
  It's not helped actually by the fact that the
• 29:17
  sun's been pretty active uh, over
• 29:20
  recent years. We've seen a lot of solar
• 29:22
  flares and um, um, coronal mass
• 29:24
  ejections and things of that sort. Uh and we
• 29:27
  know that as the subatomic
• 29:30
  particle flux from the sun increases, which
• 29:32
  it does in these events, it tends to
• 29:35
  kind of fluff up the Earth's atmosphere. Uh,
• 29:38
  it raises its height. In fact, Starlink, uh,
• 29:41
  SpaceX fell foul of that some years ago when
• 29:44
  a Number of the spacecraft that they launched
• 29:46
  didn't uh, actually make it into orbit
• 29:48
  because the Earth's atmosphere was puffed up
• 29:51
  by solar activity. So that's been happening
• 29:54
  and that's increase the um, you know, the
• 29:57
  uh, risk of re entry for
• 29:59
  Swift. So along come, uh,
• 30:02
  um, Catalyst Space Technologies
• 30:05
  and said, uh, we can do it. And
• 30:08
  they've actually built and prepared, I think,
• 30:10
  along with collaborators, a spacecraft
• 30:13
  which will be launched, uh, actually later
• 30:16
  this month, I think in about five days. Uh,
• 30:18
  at the time we're recording this, uh, if I
• 30:22
  read my uh, uh, notes on
• 30:25
  this correctly, uh,
• 30:29
  it will go to orbit. It will actually be an
• 30:31
  air launch. One of these fairly rare launches
• 30:34
  where you carry a rocket underneath the belly
• 30:36
  of a spacecraft, uh, sorry, of an aircraft,
• 30:39
  take it up to 39 or 40,000ft,
• 30:41
  then release it, uh, and the rocket
• 30:44
  burn then takes it up to orbital speed.
• 30:47
  Um, it's a great way of
• 30:50
  choosing just exactly where you want to
• 30:52
  launch from, which often has an impact on the
• 30:54
  orbit that the spacecraft will go into. So
• 30:57
  that's what's going to happen.
• 30:58
  Andrew Dunkley: That's how they used to test the space
• 31:00
  shuttles initially and drop them
• 31:03
  off. Of dropping them off a plane.
• 31:04
  Professor Fred Watson: That's correct, they did. To get their
• 31:06
  landing characteristics. And actually, um, a
• 31:09
  company called Virgin Orbital, uh,
• 31:12
  run by Mr. Virgin, uh, Richard
• 31:15
  Branson, uh, was
• 31:18
  all set uh, to kind of capture that
• 31:20
  market, but they had a failure a few years
• 31:23
  ago when they tried to launch from Cornwall
• 31:25
  and in fact wound up the company.
• 31:27
  Um, so that company doesn't exist. There are
• 31:29
  still other companies doing the same
• 31:32
  sort of thing. Uh, anyway, um, we
• 31:35
  hope that the spacecraft
• 31:38
  that will be launched, which if I remember
• 31:40
  rightly is called Link, uh, Link,
• 31:43
  will link up with Swift. Swift. It will. I
• 31:46
  think it's got three robotic arms that will
• 31:48
  grab, um, onto the Swift spacecraft
• 31:50
  and it will then
• 31:54
  fire its rockets in order to push
• 31:57
  Swift into a higher orbit and it
• 31:59
  may even stay attached so that we've
• 32:02
  got perhaps future opportunities to uh,
• 32:05
  increase its orbital height again. Yeah,
• 32:07
  yeah.
• 32:07
  Andrew Dunkley: If, if they do not succeed, and I'm not going
• 32:10
  to, to put the mocker on them, but uh, if
• 32:13
  they don't, it's likely to come crashing
• 32:15
  down. Late 2000 and twenties, early 2000 and
• 32:18
  thirties. But we've got to get to it
• 32:21
  faster than that because once it gets within.
• 32:24
  Was it 300 kilometres?
• 32:26
  Professor Fred Watson: Yeah.
• 32:26
  Andrew Dunkley: All bets are off.
• 32:28
  Professor Fred Watson: Yes, that's right. It's too high.
• 32:30
  Andrew Dunkley: It's getting pretty darn close to that now.
• 32:32
  Professor Fred Watson: Yep, it's not far off that's right.
• 32:34
  Andrew Dunkley: So they have to, they have to have this
• 32:36
  mission up and done by.
• 32:39
  I think it's October, isn't it? Or something
• 32:40
  like that.
• 32:41
  Professor Fred Watson: Yes, um, that's correct. It's
• 32:44
  got a good deal of urgency about it.
• 32:47
  I think NASA is extremely
• 32:50
  pleased that this company's risen to
• 32:53
  this and been able to do it. Uh,
• 32:55
  and so I, uh, guess what's happened is
• 32:58
  they've, you know, you've built slightly
• 33:00
  higher levels of risk into the whole process
• 33:03
  of manufacturing, designing and manufacturing
• 33:05
  it. Uh, that would not necessarily m. Be
• 33:07
  acceptable, uh, if you were doing
• 33:10
  things the conventional way, but by cutting
• 33:13
  some of that risk aversion, if I can put it
• 33:15
  that way, um, you would save, ah, time.
• 33:19
  Andrew Dunkley: All right, well, we wish them well. Um,
• 33:22
  it's going to be exciting either way, but
• 33:25
  hopefully, fingers crossed, they'll be
• 33:27
  successful and Swift will keep on
• 33:30
  keeping on. Uh, we will know very, very soon.
• 33:34
  They've got no time to muck around with this
• 33:36
  one. So, uh, we'll keep our fingers
• 33:38
  crossed for, uh. And you
• 33:41
  can read all about it@, um,
• 33:44
  arstechnica.com a
• 33:46
  r s
• 33:48
  technica.com and that just about
• 33:51
  wraps it up. Fred Watson, thank you so much.
• 33:53
  Professor Fred Watson: Ah, it's a pleasure. It's always good to have
• 33:56
  some great storeys, Andrew. Yeah, that was
• 33:58
  fun. We usually do.
• 33:59
  Andrew Dunkley: Lots of fun.
• 34:00
  Professor Fred Watson: Yeah.
• 34:01
  Andrew Dunkley: And I know we're our next planet. Um, uh,
• 34:04
  or our next holiday we'll
• 34:06
  Professor Fred Watson: be going to Pink Planet.
• 34:07
  Andrew Dunkley: The Pink Planet. Yes, that's right. We might
• 34:09
  be able to get that company to build us a
• 34:11
  rocket catalyst.
• 34:12
  Professor Fred Watson: They could probably, yeah. If you told them
• 34:14
  now, you could be away in a couple of weeks.
• 34:15
  Andrew Dunkley: Could be easily, yeah.
• 34:17
  Professor Fred Watson: It's only 57 light years.
• 34:19
  Andrew Dunkley: Uh, well, you know, plenty of time to sleep,
• 34:23
  probably. Permanent sleep. Never mind. Um,
• 34:26
  thank you, Fred Watson. We'll catch you next
• 34:27
  time.
• 34:28
  Professor Fred Watson: Uh, it's a great pleasure, Andrew. See you
• 34:30
  soon.
• 34:31
  Andrew Dunkley: Professor Fred Watson Watson, Astronomer at
• 34:33
  large. Don't forget to visit us, uh, online
• 34:35
  between
• 34:36
  episodes@spacenutspodcast.com or
• 34:38
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• 34:41
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• 34:43
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• 34:48
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• 34:50
  Just pop in there, browse. You won't be able
• 34:53
  to say no. And, uh, thanks to Huw in the
• 34:55
  studio who couldn't be with us today because
• 34:58
  he wasn't swift enough. Boom, boom.
• 35:02
  From me, Andrew Dunkley. Thanks for your
• 35:04
  company. We'll see you on the next episode of
• 35:06
  Space Nuts. Bye. Bye. You've
• 35:09
  been listening to the Space Nuts
• 35:11
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• 35:13
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