Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / Rubin’s New Dwarf Planet & Neptune’s Trojan Asteroid: Discoveries on the Solar System’s Edge

Transcript

Rubin’s New Dwarf Planet & Neptune’s Trojan Asteroid: Discoveries on the Solar System’s Edge · Space Nuts: Astronomy Insights & Cosmic Discoveries

• 0:00
  Andrew Dunkley: Hi there. Thanks for joining us on Space Nuts
• 0:03
  where we talk astronomy and space science.
• 0:06
  My name is Andrew Dunkley. It's good to have
• 0:08
  your company coming up on this edition of
• 0:10
  the show. Uh, wow.
• 0:13
  Uh, we've talked about the Vera C. Rubin
• 0:16
  Observatory and what it will mean for,
• 0:18
  uh, the future of discovery. And it's
• 0:21
  already paying big dividends because it has
• 0:24
  found a new dwarf planet
• 0:26
  and it seems to be the biggest one they have
• 0:29
  yet discovered. Tell you about that.
• 0:31
  3i Atlas is back in the news and
• 0:34
  it just got a little bit weirder. And
• 0:37
  Neptune's Trojan asteroids have been found.
• 0:40
  We always knew they were around, but we
• 0:41
  didn't know where they were. Well, it turns
• 0:43
  out the Irish had them. We'll tell you all
• 0:46
  about it on this episode of space nuts.
• 0:49
  Professor Fred Watson: 15 seconds. Guidance is internal.
• 0:52
  10, 9. Ignition
• 0:54
  sequence start.
• 0:55
  Generic: Space nuts.
• 0:56
  Professor Fred Watson: 4, 3, 2. 1, 2, 3, 4, 5.
• 0:59
  5, 4, 3, 2, 1. Space
• 1:02
  nuts. Astronauts report it feels good.
• 1:05
  Andrew Dunkley: And back to tell us all about it is
• 1:08
  Professor Fred Watson Watson, astronomer at
• 1:10
  large. Hello Fred Watson.
• 1:11
  Professor Fred Watson: Hello Andrew. Very good to see you again.
• 1:14
  Andrew Dunkley: Good to see you too. Hope you're well. You
• 1:16
  look well.
• 1:17
  Professor Fred Watson: I'm doing all right. Yeah. I think it's week
• 1:20
  10 now since the knee replacement. So.
• 1:22
  Andrew Dunkley: Huh.
• 1:22
  Professor Fred Watson: Yeah. So,
• 1:23
  Andrew Dunkley: uh,
• 1:24
  Professor Fred Watson: down
• 1:24
  Andrew Dunkley: past its trade in period.
• 1:27
  Professor Fred Watson: Yeah. Down in Victoria the weekend and
• 1:30
  cutting about like somebody with a new knee.
• 1:32
  It was um, very good.
• 1:33
  Andrew Dunkley: Good, nice. Okay,
• 1:36
  uh, uh, shall we get straight into the
• 1:39
  business of the day?
• 1:40
  Professor Fred Watson: Uh, yes, adequacy, of course.
• 1:42
  Andrew Dunkley: Yes, yes, we'll do it, we'll do it all
• 1:44
  adequately. I, I spotted this story on the
• 1:46
  weekend and I thought, wow, this new uh,
• 1:49
  observatory, Vera C. Rubin is
• 1:52
  um, this is just doing some great
• 1:55
  stuff already. It's hardly, it's hardly
• 1:57
  started doing what it's supposed to be doing,
• 1:59
  which I think is basically observing the
• 2:02
  entire known universe from the southern
• 2:04
  hemisphere. Uh, but it has found
• 2:07
  a new dwarf planet and it looks like it's a
• 2:10
  big one.
• 2:11
  Professor Fred Watson: It's relatively big. That's right. Uh,
• 2:14
  it's not the biggest, um,
• 2:16
  Andrew Dunkley: and it's not planet nine.
• 2:18
  Professor Fred Watson: It's not planet nine. No. The biggest, uh,
• 2:21
  still in terms of diameter is still Pluto,
• 2:24
  although Eris is about the same
• 2:27
  diameter but a bit more massive.
• 2:30
  Uh, which means it's made of something denser
• 2:32
  than Pluto is. And just recapping,
• 2:34
  what's a dwarf planet? A dwarf planet is
• 2:37
  an object that orbits the sun. That it is
• 2:41
  at, um, least within the solar system, it has
• 2:44
  sufficient size that its own gravity has
• 2:46
  pulled it into a spherical shape. But it has
• 2:48
  not become the dominant body in its part of
• 2:51
  the solar system. That's what distinguishes
• 2:53
  it from a planet.
• 2:55
  Andrew Dunkley: Right.
• 2:56
  Professor Fred Watson: So um, the uh, story
• 2:59
  is exactly as you've said. It's the
• 3:01
  Vera C. Rubin Observatory's legacy survey
• 3:04
  of space and time, um, which is this
• 3:07
  decade long survey of the southern sky.
• 3:10
  And what they do is they survey the
• 3:13
  entire sky every, I think it's
• 3:16
  every three nights roughly, certainly every
• 3:18
  few nights. And of course what that lets them
• 3:20
  do is um, observe things that change.
• 3:23
  So in a sense it's um, you know its main
• 3:26
  stock in trade is transportation. Transient
• 3:27
  events, whatever they are, whether they're
• 3:30
  stars that come and go.
• 3:31
  And so that includes exploding stars and
• 3:33
  things of that sort. Huh. Or objects
• 3:36
  which are moving, uh, which are ah, in the
• 3:39
  solar system. Uh, and indeed it
• 3:42
  has been uh, credited now
• 3:45
  with the discovery of a new dwarf planet.
• 3:48
  So it was one of the scientists actually,
• 3:51
  um, uh, who's part of the staff of
• 3:54
  the Vera C. Rubin Observatory,
• 3:57
  uh, uh, person by the name of Matthew Holman.
• 4:01
  Uh, he's um, on the staff
• 4:03
  but he uh, is based at the
• 4:06
  Harvard Smithsonian Centre for Astrophysics,
• 4:09
  one of the great institutions in astronomy.
• 4:11
  And basically looking through the data that
• 4:14
  Rubin collects and you know that you
• 4:17
  get well over a million
• 4:20
  alerts of something changing every night and
• 4:23
  it might be even well over 10 million. The
• 4:25
  numbers are huge. Um, and this is where
• 4:28
  basically machine learning and AI and
• 4:30
  techniques like that come into play. Because
• 4:33
  um, of these alerts of things moving or
• 4:36
  coming and going or whatever, you
• 4:38
  can't just pick them out by hand. There's so
• 4:41
  many of them that you need machines to do the
• 4:44
  job. But still at the end of the day somebody
• 4:46
  looks at the data and it was
• 4:49
  um, on the 13th of October, not
• 4:51
  very long ago that uh, Matthew Holman
• 4:54
  uh, was looking through the data and
• 4:57
  discovered an object now classified as
• 5:00
  2026 ED138.
• 5:03
  And it's um, going to be, it will
• 5:06
  eventually have a name, uh, but at the moment
• 5:09
  perhaps its identification number. Uh.
• 5:11
  Andrew Dunkley: Rodney.
• 5:12
  Professor Fred Watson: Rodney. Could be, could be.
• 5:15
  Uh, did he say Rodney?
• 5:17
  Andrew Dunkley: Rodney?
• 5:17
  Professor Fred Watson: Yeah, Rodney. Well there was a battleship
• 5:19
  called Rodney.
• 5:20
  Andrew Dunkley: Yes, I'm aware of that,
• 5:22
  Professor Fred Watson: yes. Yeah,
• 5:23
  Andrew Dunkley: so you don't. I think we should give
• 5:26
  um, planetary bodies more,
• 5:30
  you know, common names. Rodney, Trevor,
• 5:32
  Louise,
• 5:34
  Professor Fred Watson: Andrew.
• 5:35
  Andrew Dunkley: Yep, that's getting, that's getting, you
• 5:38
  know, that's getting higher up the ladder.
• 5:41
  Professor Fred Watson: Um,
• 5:41
  Andrew Dunkley: there's an object. Fred Watson.
• 5:43
  Professor Fred Watson: There's certainly an asteroid called
• 5:45
  Fred Watson Watson.
• 5:46
  Andrew Dunkley: Yeah, yep, there you
• 5:47
  Professor Fred Watson: are. But, but that leads me to um, an
• 5:50
  interesting point. That you raised there,
• 5:51
  what is it going to be called? And it will
• 5:53
  almost certainly be called after one
• 5:57
  the creation gods, uh, in
• 6:00
  the m. Mythology of the
• 6:02
  Mapuche people, who are the first nations
• 6:04
  people down there in Chile, where this
• 6:07
  telescope is based. Uh, and that's
• 6:10
  basically the protocol for naming
• 6:13
  dwarf planets in the far distant solar
• 6:16
  system, which is where this is. We didn't
• 6:17
  mention that It's a Trans Neptunian object.
• 6:19
  So it's well beyond the orbit of Neptune. In
• 6:21
  fact, it's well beyond the orbit of Pluto.
• 6:24
  Um, Pluto's on average about 6 billion
• 6:26
  kilometres away from the sun. This is more
• 6:29
  like 7 billion, not quite, but nearly 7
• 6:32
  billion kilometres away.
• 6:33
  Andrew Dunkley: Yeah, it's a heck of a long way out.
• 6:36
  It's, um, um, at least two more
• 6:39
  AU out. I think if I'm remembering that
• 6:42
  rightly, it might have been more,
• 6:43
  Professor Fred Watson: uh, it's probably more, yes. Uh,
• 6:47
  um,
• 6:48
  Andrew Dunkley: 46 astronomical units from the sun.
• 6:50
  Professor Fred Watson: Yeah. Um, but it will, as
• 6:53
  I said, end up with probably a Mapuche name
• 6:56
  which will be very nice. Um, and we are
• 6:59
  all familiar with Mapuche names because the
• 7:01
  four component telescopes of the Very Large
• 7:04
  Telescope are named after them. Um,
• 7:09
  can't remember the other two. It'll come to
• 7:11
  me in a minute.
• 7:15
  Uh, yeah, anyway, you'll find them, don't
• 7:18
  worry. And my apologies to the Mapuche people
• 7:21
  for forgetting those wonderful names which,
• 7:23
  uh, by the way, are, uh, Sun, Moon,
• 7:26
  Southern Cross and I think it's Evening
• 7:29
  Star is the other one. Might be serious. Um,
• 7:32
  I wish I hadn't drifted off in that direction
• 7:34
  because I've revealed what, uh, happens.
• 7:37
  Yeppon. Uh, and is it Melipal?
• 7:40
  Yeah, yeah,
• 7:43
  Andrew Dunkley: I'll take your word for it.
• 7:44
  Professor Fred Watson: Thanks.
• 7:47
  Um, anyway, um, there will be lovely
• 7:50
  names, a lovely name for this object. Why are
• 7:53
  we excited about it? Because it's big, um,
• 7:56
  up to possibly. And remember that you can't
• 7:59
  actually see a disc here. This is a point of
• 8:01
  light that tells us where it is by its
• 8:04
  movement because we can do the solutions of
• 8:06
  the orbital, um, equations and work out
• 8:09
  whereabouts it is from watching how fast it
• 8:12
  moves. Basically the slower something moves,
• 8:14
  the further away it is. Uh, and, um,
• 8:17
  its brightness is the only other clue that
• 8:19
  we've got. But combining those two things
• 8:22
  suggests that, um, its diameter is up
• 8:25
  to about 1500
• 8:27
  kilometres. Um, might be smaller than
• 8:30
  that, but the upper limit seems to be about
• 8:33
  1500. Uh, compare that with,
• 8:36
  um, the size of Pluto, uh, about
• 8:38
  2,000 kilometres. And I think Eris
• 8:41
  is just about the same size as well. Two
• 8:44
  similar sizes.
• 8:45
  Andrew Dunkley: Yeah. I said at the start, the biggest, I
• 8:46
  think the furthest out is. What is
• 8:48
  Professor Fred Watson: it? Probably is. Um, um,
• 8:50
  Andrew Dunkley: so far,
• 8:52
  Professor Fred Watson: certainly the furthest out of its size. Uh,
• 8:56
  um, we. It's
• 8:59
  interesting because it's going to play
• 9:01
  into the whole debate about Planet nine. Here
• 9:04
  you've got a new object. Uh, the more
• 9:06
  observations we can make, the more accurate
• 9:08
  we can determine its orbit. Uh, and um,
• 9:11
  if we find that it is a highly
• 9:14
  eccentric orbit, a highly elongated one
• 9:16
  that's aligned with all the other,
• 9:19
  um, transectunion object orbits
• 9:22
  that are aligned, then uh,
• 9:25
  it will almost certainly come into the Planet
• 9:27
  nine debate.
• 9:29
  Um,
• 9:30
  Andrew Dunkley: well, I mean one of the theories is that
• 9:33
  there may not be a Planet nine, but there may
• 9:35
  be just enough stuff out there, big stuff,
• 9:38
  to create the same effect.
• 9:42
  Professor Fred Watson: That's right. Uh,
• 9:45
  that's true. Um, although it's hard
• 9:47
  to align all these orbits
• 9:50
  without it being a single large, uh, object
• 9:53
  or
• 9:53
  Andrew Dunkley: a
• 9:53
  Professor Fred Watson: single massive object. Because, um, if it's a
• 9:56
  group of object, they're all in their own
• 9:58
  orbits. Anyway, um,
• 10:01
  there are some interesting things about this
• 10:03
  object, uh, ED138. Uh,
• 10:06
  one is it's tilted, uh,
• 10:08
  quite highly to the plane of the solar
• 10:10
  system. And that
• 10:14
  means it belongs to a category of
• 10:17
  trans neptunian objects called, and I
• 10:20
  love this, the hot classical Trans
• 10:23
  neptunian objects. Most people think of
• 10:25
  Beethoven as being the
• 10:25
  Andrew Dunkley: hot
• 10:26
  Professor Fred Watson: classical, but uh, it's actually
• 10:29
  uh, one of these. And why is it hot? Um, that
• 10:31
  relates to the energy of its orbits and the
• 10:33
  fact that it is highly, ah, inclined. M.
• 10:37
  Maybe it has been disturbed into that highly
• 10:40
  inclined orbit by interactions with the
• 10:42
  planet Neptune itself. But Neptune's actually
• 10:45
  quite a lot further in, uh, into um,
• 10:47
  the solar system. Um,
• 10:50
  Andrew Dunkley: uh, they've got a great diagram on this story
• 10:53
  on the BBC which
• 10:56
  shows the orbit. It really is a long way out.
• 11:00
  Professor Fred Watson: Yeah, yeah, it is. Um, it's
• 11:02
  um, well out of the solar system.
• 11:05
  Andrew Dunkley: Yeah, but
• 11:06
  Professor Fred Watson: it's part of it.
• 11:07
  Andrew Dunkley: It's part of it. But it's sort of like the
• 11:10
  second, uh, cousin twice removed.
• 11:12
  Professor Fred Watson: Yes, that's right. But we do know that
• 11:14
  there's this, um, relatively
• 11:17
  large population of
• 11:20
  uh, the solar system
• 11:24
  that exists way beyond the orbit of
• 11:26
  Neptune. I um, do love the diagram that
• 11:29
  you've just mentioned as well because, um, I
• 11:31
  think they've drawn it with the stars in the
• 11:33
  right position. And there's Orion in the
• 11:35
  background, which is quite nicely done.
• 11:39
  Andrew Dunkley: It looks good,
• 11:40
  Professor Fred Watson: but uh,
• 11:43
  it is a very distant object and it's tilt.
• 11:46
  It's well outside the plane of the orbit. So
• 11:48
  something has disturbed it in that
• 11:51
  regard. Um, but an exciting, you
• 11:54
  know, an exciting uh, discovery. It's
• 11:57
  Andrew Dunkley: absolutely. And a, um,
• 11:59
  another feather in the cap of the Vera C.
• 12:02
  Rubin Observatory which
• 12:05
  has just sort of,
• 12:08
  the minute they switched it on, it, it
• 12:09
  started finding stuff. And you said it
• 12:12
  would, it would change the game, it would
• 12:14
  start finding things lickety split.
• 12:17
  And that's exactly what's happening.
• 12:20
  Professor Fred Watson: Yeah, it's exciting stuff.
• 12:22
  And look, because it's looking
• 12:25
  at the transient universe and this is really
• 12:28
  an aspect of the universe that we haven't had
• 12:30
  the capability of doing before. Looking at
• 12:33
  things that come and go over short
• 12:34
  timescales. Um, that
• 12:37
  means we're almost certainly opening up a
• 12:39
  completely new discovery space here. And it's
• 12:41
  not just asteroids and dwarf planets. It's
• 12:43
  going to be all kinds of things that come um,
• 12:45
  and go in the night, whether they're moving
• 12:46
  or changing in their brightness. Um,
• 12:49
  just wait for a, an influx of um,
• 12:52
  extra, basically extra solar
• 12:55
  comets and things of that sort. Which might
• 12:57
  be a segue into one of our stories later on
• 12:59
  this month. This afternoon.
• 13:00
  Andrew Dunkley: Yeah, maybe so. Okay. If you'd like
• 13:03
  to read all about it, it's on the website
• 13:06
  BBC sky and Night magazine.
• 13:09
  Is there a published paper, Fred Watson?
• 13:11
  There's probably one.
• 13:13
  Professor Fred Watson: Oh, um, yes, there is.
• 13:16
  Uh, maybe the sky at Night hasn't given
• 13:19
  us a link to it though.
• 13:20
  Andrew Dunkley: Maybe not. But uh, yes, it
• 13:22
  Professor Fred Watson: won't be hard to find.
• 13:23
  Andrew Dunkley: Yeah,
• 13:24
  Professor Fred Watson: uh, Holman is the author.
• 13:25
  Andrew Dunkley: Indeed. All right, great, um,
• 13:28
  story and more to come. And when they give it
• 13:30
  a name, uh, Frederica or something like that,
• 13:32
  we will let you know. This is Space
• 13:35
  Nuts with Andrew Dunkley and Professor
• 13:38
  Fred Watson Watson.
• 13:41
  Professor Fred Watson: I'm going to step off the land now.
• 13:45
  That's one floral scale for man.
• 13:50
  1tr
• 13:53
  Generic: space nuts.
• 13:56
  Andrew Dunkley: Our next story takes us to an
• 13:58
  interstellar object that has been making the
• 14:01
  news continuously since it was discovered.
• 14:03
  Comet 3I Atlas. And it's
• 14:06
  in the news again, Fred Watson. And things
• 14:08
  uh, just got a little bit stranger from what
• 14:10
  I understand.
• 14:11
  Professor Fred Watson: Very unusual chemistry. Uh,
• 14:14
  so, um, I think this is the result
• 14:17
  of observations with our
• 14:20
  favourite space telescope, the James Webb
• 14:22
  Space Telescope. Um, and
• 14:26
  basically, um, uh, these observations
• 14:28
  date from December last year. Uh, it
• 14:31
  was about two and a half times as far
• 14:34
  from the sun as we are and
• 14:37
  heading basically through the asteroid belt.
• 14:40
  Uh, and um, this object, um,
• 14:44
  three I atlas clearly when it was
• 14:47
  uh, in the, you know, in that, that close
• 14:50
  up region of the solar system, we could see
• 14:52
  that it was a comet. It was releasing,
• 14:55
  um, basically dust and uh,
• 14:59
  and plasma, uh, because of the
• 15:01
  heating effect of the sun, the radiation
• 15:03
  effect of the sun, um and basically
• 15:08
  to use the technical term solar, uh,
• 15:11
  radiation sublimates its icy volatile
• 15:13
  chemicals. And what that does is
• 15:17
  we have the chance to analyse those chemicals
• 15:20
  spectroscopically. Uh, and
• 15:23
  basically uh, the
• 15:26
  scientists who've done this work have
• 15:30
  um, kind of gone to town almost on the amount
• 15:33
  of detail that they're able to put into
• 15:36
  now. The chemical um,
• 15:39
  constituents of
• 15:42
  the um, the, the object which we haven't
• 15:44
  mentioned.
• 15:45
  We're talking about Three Eye Atlas, in case
• 15:47
  we didn't mention its name earlier on or uh.
• 15:49
  Maybe you didn't. Can't
• 15:50
  Andrew Dunkley: remember anyway. I did. You didn't, but
• 15:52
  that's okay.
• 15:53
  Professor Fred Watson: Yeah. Okay. This
• 15:55
  Andrew Dunkley: uh, is, this is the third
• 15:59
  extra solar comet uh, we've found,
• 16:01
  isn't it? The third one?
• 16:02
  Professor Fred Watson: Yes. So 3i is the third interstellar.
• 16:06
  Andrew Dunkley: Yeah, of course it is.
• 16:07
  Professor Fred Watson: Um, of uh, you know, it doesn't have to be a
• 16:10
  comet. It's a, any
• 16:12
  object with that um,
• 16:15
  our uh, designation is interstellar and it
• 16:18
  could be an asteroid, it could be a comet.
• 16:20
  But this is definitely a comet,
• 16:22
  Andrew Dunkley: right?
• 16:22
  Professor Fred Watson: Not a spacecraft as some people have said.
• 16:25
  So what it's telling us though is
• 16:27
  the, you know, the details that are coming
• 16:30
  out are all about, about isotopes which
• 16:33
  we've talked about before. The number of
• 16:35
  different differing number of neutrons that
• 16:37
  there are present in a, in the nucleus of an
• 16:39
  atom. Um, and they've got
• 16:42
  isotope ratios uh, that um. In
• 16:45
  this Science Alert report, uh, which
• 16:48
  I'm looking at at the moment, um, written
• 16:51
  by Ivan uh, Farkas, uh, that
• 16:54
  uh, is basically the
• 16:57
  uh, you know, the crux that they, the isotope
• 17:00
  ratios are uh,
• 17:02
  unusual and um,
• 17:04
  basically uh, hint
• 17:07
  that at some time in the past of this
• 17:10
  object it was exposed to very
• 17:13
  high levels of radiation.
• 17:16
  Uh, and what they're speculating is that it
• 17:19
  was actually born in
• 17:22
  a gas cloud that is the sort of
• 17:25
  precursor of the core of a star.
• 17:28
  Um, um, it's a region
• 17:31
  that despite the fact that it sounds
• 17:34
  as though it should be very hot, it's
• 17:35
  actually pretty cold gas.
• 17:37
  Uh, and that is
• 17:40
  um. You know what that
• 17:43
  does is makes it very dense. It's cold, it's
• 17:46
  dense. And so it's uh, almost
• 17:49
  like ah, a refrigerator that's
• 17:52
  preserving uh, these signatures of these
• 17:55
  various isotopic ratios that we've been
• 17:57
  talking about. And the suggestion is that it
• 18:00
  was formed at a temperature of something like
• 18:02
  -260 degrees Celsius,
• 18:05
  263 degrees Celsius which is about 10 degrees
• 18:08
  above absolute zero. Uh, it's
• 18:11
  got a very low carbon content as well. One
• 18:14
  particular isotope of carbon, carbon 13, uh,
• 18:17
  which also suggests that it is
• 18:19
  very, very old. Um, in other words, it
• 18:22
  originated at
• 18:25
  a time when the universe was low in
• 18:29
  what we call heavier elements. Um, because
• 18:31
  heavier elements basically increase
• 18:34
  in their numbers, um,
• 18:37
  as the universe gets older. And that's
• 18:40
  because they're formed in the interiors of
• 18:41
  stars and subsequent
• 18:44
  generations of stars, uh, mean that the
• 18:47
  universe is gradually enriched with these
• 18:49
  heavier elements.
• 18:51
  Andrew Dunkley: Extraordinary. Extraordinary. And, uh,
• 18:54
  it seems to also have,
• 18:57
  um, a much more significant,
• 19:00
  uh, methane, heavy methane content than
• 19:03
  anything else we've looked at.
• 19:06
  Professor Fred Watson: That's right. Um, that's
• 19:09
  one of the features of this unusual chemistry
• 19:12
  that we mentioned at the beginning.
• 19:16
  Um, very, very interesting that it has got
• 19:18
  this very high, what's called
• 19:21
  a D to H ratio. That's deuterium to
• 19:24
  hydrogen. And deuterium is heavy hydrogen.
• 19:26
  It's hydrogen with an extra neutron.
• 19:30
  That ratio for methane, um,
• 19:33
  as they say in this article, that elevated D
• 19:35
  to H ratio for methane in 3i Atlas is
• 19:38
  consistent with the hypothesis that its ice
• 19:41
  is formed in a cold, low
• 19:43
  metallicity interstellar or
• 19:45
  protostellar environment under a high
• 19:50
  cosmic ray irradiation rate.
• 19:53
  Uh, that's a quote from the researchers
• 19:54
  who've, uh, done this study.
• 19:58
  So the bottom line is that
• 20:00
  the age that is being Put now on
• 20:03
  Three Eye Atlas is something like 10
• 20:06
  billion years. And that is,
• 20:09
  you know, what is it? 4/5 of the
• 20:12
  age of the universe. Yeah.
• 20:14
  Um, that's
• 20:15
  Andrew Dunkley: amazing.
• 20:15
  Professor Fred Watson: It may have lurked in its own solar system
• 20:18
  for 3 billion years. They think it's been
• 20:20
  travelling perhaps for 7 billion years. Uh,
• 20:23
  and that's of course, 3 billion years before
• 20:25
  our solar system even existed. So
• 20:28
  really quite extraordinary.
• 20:29
  Andrew Dunkley: So I probably got kicked out by, you
• 20:32
  know, for not paying the rent or something.
• 20:35
  Professor Fred Watson: Yeah, it could, it's more likely to be
• 20:37
  gravitational interactions, but it could just
• 20:39
  be not paying the rent. You're right. Yeah.
• 20:41
  Andrew Dunkley: Yeah. Well, it's another,
• 20:44
  um, amazing discovery and I just
• 20:48
  find it extraordinary that something so
• 20:50
  far away, so small and so fast
• 20:54
  you can get a few snapshots of it as it's
• 20:57
  passing by through the likes of the James
• 20:59
  Webb telescope. And then you can study it
• 21:02
  and just unravel everything about it that,
• 21:05
  um, it consists of. And,
• 21:08
  yeah, I'm stunned by this new,
• 21:11
  um, era of telescopic
• 21:13
  capability.
• 21:16
  Professor Fred Watson: It is, yeah, it is
• 21:19
  remarkable, um, where we are at the moment,
• 21:22
  even compared with two years ago, maybe.
• 21:25
  When was it? 20, 21 when, uh, uh,
• 21:28
  the web was deployed. So, yeah,
• 21:30
  certainly compared with a decade ago. We're
• 21:33
  in an extraordinary situation.
• 21:35
  Andrew Dunkley: We certainly are, notwithstanding what
• 21:36
  Hubble's achieved. But, yeah. And it's still
• 21:39
  going strong. Still going strong, yeah.
• 21:42
  If you'd like to read about it, uh,
• 21:43
  sciencealert.com or you can read the study
• 21:46
  in the journal Nature Astronomy. This
• 21:49
  is Space Nuts, Andrew Dunkley here with
• 21:51
  Professor Fred Watson Watson.
• 21:57
  Generic: Space Nuts.
• 21:57
  Andrew Dunkley: Now, Fred Watson, our final story takes us,
• 21:59
  uh, back to the outer reaches of the solar
• 22:02
  system. Not as far as, uh, dwarf planet
• 22:04
  2026. Ed. Ah, 138. But getting out there,
• 22:08
  uh, we're looking at, uh, asteroids
• 22:11
  in the, uh, Neptunian part, ah.
• 22:13
  Of the, um, uh, solar
• 22:16
  system. What's interesting about this is
• 22:19
  that, um, other planets have got these
• 22:21
  asteroids. But, uh, they've never been able
• 22:24
  to find Neptune's, uh, Trojan
• 22:27
  asteroids until now. Because,
• 22:29
  uh, a team in Belfast has made the
• 22:32
  discovery.
• 22:34
  Professor Fred Watson: Exactly. And guess what they've been using to
• 22:36
  make the discovery.
• 22:37
  Andrew Dunkley: Vera C. Rubin Telescope.
• 22:39
  Professor Fred Watson: Yes, that's right.
• 22:40
  Andrew Dunkley: Yeah. Again,
• 22:43
  Professor Fred Watson: um, technically, it's the observatory that's
• 22:45
  called Vera C. Rubin. The telescope has a
• 22:48
  different name, uh, from its benefactor.
• 22:51
  That'll come to me in a minute as well. But
• 22:53
  we usually refer it to it as the Vera C.
• 22:56
  Rubin Observatory. That's right. Um,
• 23:00
  so, uh, it is a
• 23:03
  discovery that exactly as you've said,
• 23:06
  sort of dots the I's and crosses the T's of
• 23:09
  our understanding of these, uh,
• 23:12
  objects. Which we call Trojan asteroids. And
• 23:14
  just to remind our listeners, uh, and
• 23:17
  viewers, um, Trojan asteroids are,
• 23:19
  uh, objects that are not in
• 23:22
  the main asteroid belt between the orbits of
• 23:25
  Mars and Jupiter. They lurk,
• 23:28
  uh, 60 degrees in front of and
• 23:31
  60 degrees behind, um,
• 23:34
  planets. And the best known ones, and
• 23:37
  in fact, the only known ones.
• 23:38
  When I was a young astronomer, my supervisor
• 23:41
  used to work on them. Actually, my, um,
• 23:42
  master's degree supervisor at St. Andrews,
• 23:45
  he worked on these objects. They were the
• 23:47
  ones before and after the planet Jupiter.
• 23:50
  Ah. Uh, but sitting in Jupiter's orbit, the
• 23:53
  Jupiter Trojans, um, at an angle,
• 23:55
  I should say, of 60 degrees. So 60
• 23:58
  degrees ahead of Jupiter, there's one bunch
• 24:00
  of them. 60 degrees behind Jupiter, there is
• 24:03
  another. And they are called, uh. The two
• 24:05
  groups are named Trojan and Greek
• 24:08
  populations. And I can never remember which
• 24:10
  way around they are. I think the Trojan ones
• 24:12
  are the ones at the front. They're the ones
• 24:14
  that go first. Uh, anyway, um,
• 24:16
  so here's the conundrum. Um, we
• 24:19
  know about the Trojans of the planet
• 24:22
  Saturn. We know about the Trojans of the
• 24:25
  planet Jupiter, uh, and Uranus,
• 24:28
  but they have never been found for
• 24:30
  Neptune. So um,
• 24:33
  that is why this is such a
• 24:36
  breakthrough because these uh, scientists,
• 24:38
  yes as you've said, led uh, from Queen's
• 24:41
  University in Belfast and I think
• 24:44
  there's a fairly high degree
• 24:47
  of student uh, members to uh, this
• 24:50
  team. They're at the Astrophysics Research
• 24:53
  Centre at Queen's University. Ah, Meg
• 24:56
  Schwamb, uh. Is uh, an
• 24:58
  astronomer and lecturer there and basically
• 25:02
  led the team of uh, scientists
• 25:04
  working on this including um.
• 25:07
  Uh, some uh, other international
• 25:10
  colleagues, um, and of course using
• 25:13
  the Vera C. Rubin Observatory's
• 25:16
  telescope.
• 25:17
  So, um, how's the discovery been made
• 25:20
  just by what we were talking about a bit
• 25:22
  earlier this session, Andrew, that
• 25:25
  um. The telescope basically
• 25:27
  photographs the entire sky um,
• 25:30
  every three nights. And so if you're looking
• 25:33
  for things that move, that's the way to do
• 25:35
  it. The planet Neptune will have been in
• 25:37
  their field of view at one point and they
• 25:39
  probably subtracted that from the images. Uh,
• 25:42
  but that would have allowed them to see
• 25:45
  uh, this excess of numbers of asteroids
• 25:48
  which fit into the place that we're talking
• 25:50
  about 60 degrees before and
• 25:53
  after, uh, Neptune, but sitting in its
• 25:56
  orbit. So a big triumph actually
• 25:58
  for the uh. Um. Ulster team,
• 26:01
  the Northern Ireland team.
• 26:04
  Andrew Dunkley: I wonder why it's been so hard to nail this
• 26:06
  down. I mean they found nuggets floating
• 26:08
  around Uranus. But, uh. Why
• 26:11
  haven't. I, couldn't help it.
• 26:13
  Why haven't
• 26:14
  Professor Fred Watson: that
• 26:15
  Andrew Dunkley: one.
• 26:18
  Why haven't they been able to until now find
• 26:21
  these objects around Neptune? What makes
• 26:23
  Neptune so difficult?
• 26:25
  Professor Fred Watson: Uh, it's much further away. It's quite
• 26:27
  simple. Um. Um. We think
• 26:30
  of. Yes. Oh yes. Jupiter, Saturn, Uranus and
• 26:33
  Neptune. We think of them as being in a row
• 26:34
  and nicely spaced out, but they're not. The
• 26:37
  distance kind of doubles from each
• 26:40
  one. So, uh, from,
• 26:43
  um. Jupiter. Sorry, from uh.
• 26:46
  Let's get this right. From Uranus to Neptune
• 26:48
  is twice as much as it is from. Basically
• 26:50
  twice as much as it is from Saturn to
• 26:52
  Neptune.
• 26:53
  Andrew Dunkley: And
• 26:54
  Professor Fred Watson: of course, because the brightness of an
• 26:56
  object varies with one over the square
• 26:59
  of its distance, that means, um, that
• 27:02
  it gets fainter very much quicker. So it's
• 27:05
  all about the brightness of these objects.
• 27:06
  Uh, they're below the threshold for
• 27:09
  visibility for most of the telescopes
• 27:12
  that have looked for them before. But yeah,
• 27:15
  Andrew Dunkley: you've got to remember it's really dark out
• 27:17
  there. I mean the sunlight gets there.
• 27:19
  But I think, uh. I can't remember where I
• 27:21
  read it, but Pluto, um, for
• 27:24
  example, daytime is like, like Twilight
• 27:27
  on Earth. I think
• 27:27
  Professor Fred Watson: I would say that's correct. Yes. Yeah.
• 27:31
  Andrew Dunkley: Uh, it is a really dark place. And cold.
• 27:34
  Professor Fred Watson: Yep. All of that. No point in putting your
• 27:37
  solar panels up there because you're not
• 27:38
  going to get much juice from them
• 27:40
  Andrew Dunkley: unless you get one the size of a planet.
• 27:43
  Professor Fred Watson: Yes. Which
• 27:45
  Andrew Dunkley: sort of defeats the purpose. I suppose
• 27:46
  Professor Fred Watson: it does.
• 27:48
  Andrew Dunkley: Although the way things are going on Earth,
• 27:51
  we've just about got a solar panel the size
• 27:53
  of a planet.
• 27:54
  Professor Fred Watson: Yes, it might work that way. That's right.
• 27:56
  Andrew Dunkley: Saw a lot of them in Eastern Europe which
• 27:58
  surprised me. But, um, yeah, they are
• 28:00
  everywhere. But, um, they're almost
• 28:03
  outnumbered by wind turbines.
• 28:05
  Professor Fred Watson: Yes. Yes.
• 28:07
  Andrew Dunkley: That's a whole other story. Uh, yeah, if you
• 28:10
  would like to read about the um,
• 28:13
  uh, discovery of the Neptunian
• 28:16
  Trojan asteroids, you can do so
• 28:18
  on universetoday.com or you can check
• 28:21
  out the paper at the Astrophysical Journal
• 28:24
  Letters. That brings us to the end.
• 28:26
  Fred Watson. Thank you.
• 28:28
  Professor Fred Watson: That went quick. Um,
• 28:30
  Andrew Dunkley: nice
• 28:30
  Professor Fred Watson: to talk to you again, Andrew. Good to
• 28:33
  Andrew Dunkley: talk to you. We stayed
• 28:33
  Professor Fred Watson: in the solar system this time, but um, no
• 28:36
  doubt we'll venture further afield in future
• 28:38
  episodes
• 28:39
  Andrew Dunkley: for sure. Possibly the next one. We'll see
• 28:41
  what people are asking us in our Q and A
• 28:43
  episode. See you soon, Fred Watson. Thank
• 28:45
  you.
• 28:46
  Professor Fred Watson: Sounds great. Cheers, Andrew.
• 28:47
  Andrew Dunkley: Professor Fred Watson Watson, astronomer at
• 28:50
  large. And don't forget to visit us between
• 28:51
  episodes on our website or on social
• 28:54
  media. We've got uh, a very strong presence
• 28:57
  on Facebook, the official Space Nuts
• 29:00
  page. Or you can go to the podcast group
• 29:02
  which uh, is like minded. People chatting to
• 29:05
  each other, sharing their um, their
• 29:07
  images and discussions and all that. Um,
• 29:10
  just space, uh, Nuts podcast group on
• 29:13
  Facebook. Uh, and yeah, I think
• 29:15
  we're on uh, YouTube. I know we are because
• 29:19
  we're on it right now. Ah, going out live
• 29:22
  and uh, um. What's the other one? Instagram.
• 29:26
  So yeah, check it all out there. And thanks
• 29:28
  to Huw in the studio. Couldn't be with us.
• 29:30
  Every time Three Eye Atlas makes the news, he
• 29:32
  thinks he has to go out and buy the latest
• 29:34
  edition of his atlas. It's.
• 29:37
  I'm not telling him. Not going to tell him.
• 29:40
  And from me, Andrew Dunkley, thanks for your
• 29:42
  company. We'll catch you on the next episode
• 29:43
  of Space Nuts. Bye. Uh, bye.
• 29:46
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• 29:48
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• 29:49
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• 30:00
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  production from bytes.com. um,