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Space Nuts: Unraveling the Mysteries of NGC 4698 and Chariklo's Rings
In this exciting episode of Space Nuts, hosts Andrew Dunkley and Professor Fred Watson explore some truly peculiar cosmic phenomena. They kick off with a deep dive into the strange behaviour of the galaxy NGC 4698, known for its unusual rotational patterns and mysterious bulge, leading to discussions about possible galactic mergers. Next, the duo ventures into the intriguing world of Chariklo, a centaur object with changing rings, as they discuss the latest observations from the James Webb Space Telescope and the implications of its unique ring structure. Join Andrew and Fred Watson as they navigate these captivating astronomical tales with their signature blend of humour and insight.
Key topics
- The peculiar characteristics of NGC 4698: What makes this galaxy behave strangely?
- Insights into the dynamics of galaxy mergers and their effects on structure.
- Chariklo's rings: How have they changed since their discovery, and what does this mean for our understanding of ring systems?
- The potential existence of a hidden moon influencing the structure of Chariklo's rings.
Timestamps
00:00 - Introduction and overview of today's topics
01:20 - Discussion on the peculiar galaxy NGC 4698 and its unusual features
15:30 - Exploring Chariklo and the changes in its ring system
25:00 - Insights from the James Webb Space Telescope and the hidden moon hypothesis
35:15 - Final thoughts and listener engagement
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00:00:00 --> 00:00:01 Andrew Dunkley: Hi there. Thanks for joining us on yet
00:00:01 --> 00:00:04 another edition of the Space Nuts
00:00:04 --> 00:00:06 podcast. My name is Andrew Dunkley, your host
00:00:06 --> 00:00:09 and it's good to have your company as we look
00:00:09 --> 00:00:12 into these, uh, issues, you call them issues
00:00:12 --> 00:00:15 stories. Uh, there's a really weird
00:00:15 --> 00:00:17 galaxy out there. It's got a really
00:00:17 --> 00:00:20 odd rotational pattern, uh, and
00:00:20 --> 00:00:21 one wonders why.
00:00:21 --> 00:00:24 I have a theory, but it's probably wrong. Uh,
00:00:24 --> 00:00:27 we're also going to look at the changing
00:00:27 --> 00:00:30 rings of Chariklo. What is
00:00:30 --> 00:00:32 that? It's a weird thing in a weird
00:00:32 --> 00:00:35 place I think is the best way to describe it.
00:00:35 --> 00:00:37 And we don't need to talk about it anymore.
00:00:37 --> 00:00:40 And we've got a juicy story from ESA as well.
00:00:40 --> 00:00:43 That's all coming up on this episode of
00:00:43 --> 00:00:44 Space Nuts.
00:00:44 --> 00:00:46 Professor Fred Watson: 15 seconds. Guidance within channel
00:00:47 --> 00:00:49 N9. Ignition
00:00:49 --> 00:00:50 sequence star.
00:00:50 --> 00:00:51 Professor Fred Watson: Uh, SpaceNets.
00:00:51 --> 00:00:54 Professor Fred Watson: 5, 4, 3, 2, 1. 3, 3, 4,
00:00:54 --> 00:00:57 5, 5, 4, 3, 2', 1. Space
00:00:57 --> 00:00:59 Nuts astronauts reported. Neil.
00:00:59 --> 00:00:59 Good.
00:01:01 --> 00:01:02 Andrew Dunkley: Actually, we've got a couple of stories from
00:01:02 --> 00:01:05 ESA today. Joining us to explain all
00:01:05 --> 00:01:08 of that mystery that I just unveiled is
00:01:08 --> 00:01:10 Professor Fred Watson Watson, astronomer at
00:01:10 --> 00:01:11 large. Hello Fred Watson.
00:01:11 --> 00:01:13 Professor Fred Watson: Good morning. Uh, uh, what's your name again?
00:01:13 --> 00:01:16 Andrew. Yeah, that's it, sorry. Dave.
00:01:16 --> 00:01:19 Andrew Dunkley: Dave. I've copped that many times. I still
00:01:19 --> 00:01:21 get that now. That was years ago that
00:01:21 --> 00:01:23 somebody accidentally calls me Dave. And
00:01:24 --> 00:01:25 it's still going.
00:01:25 --> 00:01:28 Professor Fred Watson: Part of Space Nuts legend is that
00:01:28 --> 00:01:31 Andrew Dunkley: my best friend's name is Dave. So I'm not
00:01:31 --> 00:01:31 offended.
00:01:31 --> 00:01:34 Professor Fred Watson: Uh, could be, actually. Um, I've got several
00:01:34 --> 00:01:35 really close friends who are Dave's as well,
00:01:35 --> 00:01:37 so must be what it is.
00:01:39 --> 00:01:41 Anyway, Dave, it's nice to talk to you again.
00:01:41 --> 00:01:42 Andrew Dunkley: Thank you, Fred Watson.
00:01:43 --> 00:01:43 Professor Fred Watson: Um,
00:01:45 --> 00:01:46 Professor Fred Watson: I usually get Frank.
00:01:47 --> 00:01:47 Andrew Dunkley: Do you?
00:01:47 --> 00:01:50 Professor Fred Watson: Uh, sometimes I get Greg. Yeah. When people
00:01:50 --> 00:01:52 m. Mishear the consonants.
00:01:53 --> 00:01:56 Okay, so it's when you, you know
00:01:56 --> 00:01:58 when you go and order a coffee and they say
00:01:58 --> 00:02:00 what's your name? So they can yell out your
00:02:00 --> 00:02:01 name when your coffee's ready. Yeah.
00:02:01 --> 00:02:04 And um, so I expect Greg or
00:02:05 --> 00:02:07 you know, Ted or anything that's got
00:02:07 --> 00:02:09 different consonants. And occasionally I get
00:02:09 --> 00:02:10 Frank as well.
00:02:10 --> 00:02:12 Andrew Dunkley: Well, my elder, I've got a better one than
00:02:12 --> 00:02:15 that. Uh, my eldest son's name is Kyle. K
00:02:15 --> 00:02:17 Y L E. And uh,
00:02:18 --> 00:02:20 this turned into a Facebook, um,
00:02:20 --> 00:02:23 epidemic, uh, at one stage where
00:02:23 --> 00:02:25 he'd go and order a coffee down in Sydney
00:02:25 --> 00:02:28 somewhere and then they'd call out Kylie,
00:02:29 --> 00:02:32 Kylie. And they'd even
00:02:32 --> 00:02:33 written Kylie on the car.
00:02:33 --> 00:02:34 Professor Fred Watson: Ah, yeah, yeah.
00:02:34 --> 00:02:36 Andrew Dunkley: And every time it happened he'd take a photo
00:02:36 --> 00:02:39 and go put it on Facebook and go what the
00:02:39 --> 00:02:41 bleep? And it still
00:02:41 --> 00:02:44 happens. To him. But he's been down there
00:02:44 --> 00:02:46 for, I don't know, 15 years now. And, um,
00:02:47 --> 00:02:49 he still gets called Kylie.
00:02:50 --> 00:02:52 Professor Fred Watson: I don't understand. Could be there.
00:02:52 --> 00:02:55 Andrew Dunkley: Anyway, he hates us because we named him, so.
00:02:55 --> 00:02:55 Anyway.
00:02:55 --> 00:02:56 Professor Fred Watson: Yeah, yeah.
00:02:56 --> 00:02:57 Professor Fred Watson: Why did he call him Kyle?
00:02:58 --> 00:03:00 Andrew Dunkley: Uh, that's a funny story too, because, uh,
00:03:01 --> 00:03:04 when Judy fell pregnant and I'm
00:03:04 --> 00:03:05 still trying to find the man that did it.
00:03:05 --> 00:03:08 Anyway, um, when
00:03:08 --> 00:03:10 Judy fell pregnant, we were sitting in the
00:03:10 --> 00:03:12 lounge room saying, what are we going to call
00:03:12 --> 00:03:15 him? And we were watching the movie the
00:03:15 --> 00:03:18 Terminator. And the original one, the
00:03:18 --> 00:03:20 very first one, and the. And the, um,
00:03:20 --> 00:03:23 hero's name in that was Kyle. I said, that's
00:03:23 --> 00:03:25 a nice name. And Judy said, yeah, yeah, let's
00:03:25 --> 00:03:25 go with that.
00:03:26 --> 00:03:28 So it's from the mo Movie the Terminator.
00:03:28 --> 00:03:31 There's. There's no family connection
00:03:31 --> 00:03:33 whatsoever with the name. We just liked it
00:03:34 --> 00:03:35 from the film.
00:03:37 --> 00:03:39 Professor Fred Watson: I thought you might. There might be a link
00:03:39 --> 00:03:42 with Scotland there. Uh, no, Kyle is
00:03:42 --> 00:03:45 an estuary. Oh, is it kind of
00:03:45 --> 00:03:47 local? Of Sutherland. Yeah. So he's an
00:03:47 --> 00:03:48 estuary. That's his name.
00:03:49 --> 00:03:51 Andrew Dunkley: I mean, there's a bit of Scottish heritage in
00:03:51 --> 00:03:53 our family, so that probably works.
00:03:53 --> 00:03:53 Professor Fred Watson: That'll.
00:03:53 --> 00:03:54 Andrew Dunkley: That'll do.
00:03:54 --> 00:03:55 Professor Fred Watson: Yeah.
00:03:55 --> 00:03:55 Professor Fred Watson: Yeah.
00:03:56 --> 00:03:58 Andrew Dunkley: And our other two, we. We picked Morgan for a
00:03:58 --> 00:03:59 girl and never had a girl.
00:03:59 --> 00:04:01 So when we had our second boy, we went, well,
00:04:01 --> 00:04:04 let's just use that just in case.
00:04:04 --> 00:04:06 And then the third one came along and we
00:04:06 --> 00:04:08 were. We were still devoid of names. And I
00:04:08 --> 00:04:11 said, well, why not Lachlan? You know, we're
00:04:11 --> 00:04:13 not far from the Lachlan River. Let's just
00:04:13 --> 00:04:15 stick with Lachlan. So that's how that
00:04:15 --> 00:04:17 happened as well.
00:04:17 --> 00:04:18 Professor Fred Watson: Yeah.
00:04:18 --> 00:04:19 Andrew Dunkley: Yeah, it is. It is, yeah.
00:04:20 --> 00:04:20 Professor Fred Watson: There you go.
00:04:21 --> 00:04:24 Andrew Dunkley: Hmm. Yeah. I hadn't thought about
00:04:24 --> 00:04:26 how we named our kids, and I haven't thought
00:04:26 --> 00:04:29 about it for years. And they never asked, so
00:04:29 --> 00:04:30 I. We don't go there.
00:04:32 --> 00:04:35 Professor Fred Watson: We'll do another episode, uh, down the track
00:04:35 --> 00:04:37 and I'll tell you how, uh, we. Why we
00:04:37 --> 00:04:40 named our kids. All right. Yeah,
00:04:40 --> 00:04:42 no, we won't do it now. We won't do it now.
00:04:42 --> 00:04:43 Andrew Dunkley: We'll do it in the next episode.
00:04:43 --> 00:04:44 Professor Fred Watson: Do it in the next episode.
00:04:45 --> 00:04:48 Andrew Dunkley: We should do some stories, though. Um, now
00:04:48 --> 00:04:48 this.
00:04:48 --> 00:04:51 This one's really weird and it's
00:04:51 --> 00:04:54 all to do with observ of a
00:04:54 --> 00:04:57 very strange, uh, galaxy,
00:04:57 --> 00:05:00 uh, that's behaving badly. Or is it just
00:05:00 --> 00:05:02 behaving strangely? Has it had too much to
00:05:02 --> 00:05:03 drink? Fred Watson?
00:05:03 --> 00:05:06 Professor Fred Watson: It could be. Certainly. It probably is a
00:05:06 --> 00:05:08 digestive issue, uh, for the galaxy.
00:05:08 --> 00:05:10 Andrew Dunkley: I was gonna Say that that was my theory. I
00:05:10 --> 00:05:13 bet this is a result of a galaxy merger.
00:05:13 --> 00:05:15 Professor Fred Watson: Yeah, I think that's right. That's the
00:05:15 --> 00:05:17 general view of it. So the galaxy we're
00:05:17 --> 00:05:19 talking about, it's actually not. It's a
00:05:19 --> 00:05:22 nearby galaxy. It's um, 55
00:05:22 --> 00:05:24 million light years away. That's very
00:05:24 --> 00:05:26 much uh, our uh, local backyard. So the
00:05:26 --> 00:05:28 images that we see of it are very, very
00:05:28 --> 00:05:31 detailed. There's a beautiful image, uh,
00:05:31 --> 00:05:33 which I think is on both the ESA and NASA
00:05:33 --> 00:05:36 website because it's a Hubble telescope
00:05:36 --> 00:05:38 image. And of course the Hubble telescope is
00:05:39 --> 00:05:41 um, um, funded by both and uh,
00:05:41 --> 00:05:44 operated by both. Um. Uh,
00:05:44 --> 00:05:47 it's a spiral galaxy, uh, in
00:05:47 --> 00:05:49 the constellation Virgo. As I said, 55
00:05:49 --> 00:05:52 million light years away. Uh, it's one
00:05:52 --> 00:05:55 member of the Virgo Cluster, which
00:05:55 --> 00:05:58 is one of the biggest nearby galaxy clusters
00:05:58 --> 00:06:00 that we can see. Um, there's something like a
00:06:00 --> 00:06:03 thousand galaxies in it. Um, there are a
00:06:03 --> 00:06:06 few really big ones, the Coma Cluster, uh,
00:06:06 --> 00:06:09 Virgo Cluster, a few in our locality. And
00:06:09 --> 00:06:11 they're big, they're big, um, galaxy
00:06:11 --> 00:06:12 clusters.
00:06:12 --> 00:06:15 So um, when you look at
00:06:15 --> 00:06:18 this, there's a lovely Hubble telescope image
00:06:18 --> 00:06:20 that I guess is the centre of uh,
00:06:21 --> 00:06:23 attention on this story. Um,
00:06:24 --> 00:06:27 beautiful image of this galaxy, spiral
00:06:27 --> 00:06:29 arms, which unlike
00:06:30 --> 00:06:32 the spiral arms of our Milky Way
00:06:32 --> 00:06:35 galaxy, we think they are at their
00:06:35 --> 00:06:38 inner edge firmly pinned down to the
00:06:39 --> 00:06:41 um, central bar of the galaxy. That
00:06:41 --> 00:06:44 means when you look at it, and we clearly
00:06:44 --> 00:06:47 can't look at our own galaxy in a photograph
00:06:47 --> 00:06:49 because we're right inside it. Uh, we can't
00:06:49 --> 00:06:51 look at the whole thing but we can map it
00:06:51 --> 00:06:54 through infrared and radio astronomy. And um,
00:06:54 --> 00:06:56 the evidence seems to be that there is a bar,
00:06:57 --> 00:06:59 uh, at the centre. Now that's not a bar you
00:06:59 --> 00:07:02 lean against. It's an elongated distribution
00:07:02 --> 00:07:04 of stars, uh, and
00:07:04 --> 00:07:06 um, with some really interesting dynamics,
00:07:06 --> 00:07:09 really interesting movement in it. Uh, but
00:07:09 --> 00:07:12 our spiral arms, uh, are uh, sort of
00:07:12 --> 00:07:14 fixed to the end of the bar. That's where
00:07:14 --> 00:07:16 they seem to originate from. Um,
00:07:16 --> 00:07:19 whereas with ah, this particular galaxy, and
00:07:19 --> 00:07:22 I haven't given it its name, it is NGC
00:07:22 --> 00:07:24 4698. A uh, lovely,
00:07:24 --> 00:07:27 um, meaningless name. Um,
00:07:28 --> 00:07:30 uh, NGC stands for New General Catalogue
00:07:30 --> 00:07:32 which if I remember rightly was published in
00:07:32 --> 00:07:34 1888. Uh, so it's still pretty new
00:07:35 --> 00:07:37 really. NGC
00:07:37 --> 00:07:40 4698. Uh, the point
00:07:40 --> 00:07:42 about this galaxy is when you look at it you
00:07:42 --> 00:07:44 can see spiral arms, but they're sort of
00:07:44 --> 00:07:47 only in the outer, I guess the
00:07:47 --> 00:07:49 outer third of the galaxy.
00:07:49 --> 00:07:52 And in the middle there's no sign of
00:07:52 --> 00:07:55 spiral arms. So that straight away
00:07:55 --> 00:07:56 tells you that there's something different
00:07:57 --> 00:07:59 about this object. Um, the
00:07:59 --> 00:08:02 other thing, and the thing that is, I guess,
00:08:02 --> 00:08:05 really remarkable is what we
00:08:05 --> 00:08:07 slightly unflatteringly refer to as the bulge
00:08:07 --> 00:08:10 of the galaxy. Um, our galaxy has a bulge.
00:08:10 --> 00:08:13 Uh, it's, uh, what is often known as a
00:08:13 --> 00:08:16 peanut bulge because it's kind of vaguely
00:08:16 --> 00:08:18 peanut shaped. And that probably comes about
00:08:18 --> 00:08:20 because of the, the bar in the centre of our
00:08:20 --> 00:08:23 galaxy. Uh, we see it from our vantage point
00:08:23 --> 00:08:26 here in the solar system. We see it in the
00:08:26 --> 00:08:28 constellation of Sagittarius. And,
00:08:28 --> 00:08:31 um, if you look on winter nights
00:08:31 --> 00:08:33 at the Milky Way, when it's nearly overhead,
00:08:34 --> 00:08:37 that's where it is at its widest. There is a
00:08:37 --> 00:08:40 sort of big swath of stars there
00:08:40 --> 00:08:42 and that's the bulge of our own galaxy. So
00:08:42 --> 00:08:45 you can kind of see it with the naked eye.
00:08:45 --> 00:08:48 Uh, this one has a bulge as well, which is
00:08:48 --> 00:08:50 elongated a bit like ours, but
00:08:51 --> 00:08:53 it's elongated in the wrong direction.
00:08:54 --> 00:08:55 It stretches out
00:08:56 --> 00:08:58 perpendicular to the disc of the
00:08:58 --> 00:09:01 galaxy. And that is a rarity.
00:09:01 --> 00:09:04 I don't think it's unique, but I think it's
00:09:04 --> 00:09:07 pretty rare. Uh, and
00:09:07 --> 00:09:09 so what, um, is
00:09:10 --> 00:09:13 perhaps the smoking
00:09:13 --> 00:09:15 gun about how this originated
00:09:16 --> 00:09:19 is that when you look at the movement of
00:09:19 --> 00:09:21 stars within that perpendicular bulge,
00:09:22 --> 00:09:25 um, you find that the motion of the stars is
00:09:25 --> 00:09:27 perpendicular to the rest of the galaxy as
00:09:27 --> 00:09:29 well. So it's not just that it looks as
00:09:29 --> 00:09:31 though it's at right angles, it really is
00:09:31 --> 00:09:34 because the stars are moving in that
00:09:34 --> 00:09:37 direction, uh, up and down through the centre
00:09:37 --> 00:09:39 of the galaxy, rather than, uh,
00:09:40 --> 00:09:43 swirling around in the same plane as the disc
00:09:43 --> 00:09:43 of the galaxy.
00:09:44 --> 00:09:45 Andrew Dunkley: Yeah, I don't, you know,
00:09:47 --> 00:09:50 is that possibly a rarity or is
00:09:50 --> 00:09:52 this most likely more common than we think
00:09:52 --> 00:09:55 we've just happened to find? The first one
00:09:55 --> 00:09:56 that looks this way.
00:09:56 --> 00:09:57 Professor Fred Watson: Uh, yeah, that's a good question.
00:09:57 --> 00:10:00 Is it, um, you know, is it a selection effect
00:10:00 --> 00:10:03 that we normally don't see that. But I
00:10:03 --> 00:10:06 think it is more likely that this is
00:10:06 --> 00:10:09 quite rare because, um, certainly the
00:10:09 --> 00:10:12 imagery of this object, uh, is
00:10:12 --> 00:10:14 very striking. When you look at it, you can
00:10:14 --> 00:10:17 see straight away that its bulge is
00:10:17 --> 00:10:20 different from, uh, normal
00:10:20 --> 00:10:22 galaxies, that it's got this, uh,
00:10:23 --> 00:10:26 sprinkling of stars which are well above the
00:10:26 --> 00:10:27 plane of the galaxy and that's not what you
00:10:27 --> 00:10:30 expect from, uh, the bulge.
00:10:30 --> 00:10:32 Andrew Dunkley: So you can see it in the image. It's a
00:10:32 --> 00:10:34 beautiful image, by the way, isn't it?
00:10:34 --> 00:10:36 Professor Fred Watson: Isn't it lovely? Um, there's other
00:10:37 --> 00:10:39 fainter galaxies in the background, which,
00:10:39 --> 00:10:41 um, are always nice to see, it looks as
00:10:41 --> 00:10:44 though, um, uh,
00:10:44 --> 00:10:47 the dust is showing up very clearly, uh,
00:10:48 --> 00:10:51 reddish in this image. And that's
00:10:51 --> 00:10:53 probably a true colour as well. So it looks
00:10:53 --> 00:10:55 like the dust looks like gravy swirling
00:10:55 --> 00:10:57 around, uh, the spiral arms at the outer side
00:10:57 --> 00:11:00 of the galaxy. But, um, yes, it's a
00:11:00 --> 00:11:03 very, very, uh, attractive image.
00:11:04 --> 00:11:05 So, um, the reason
00:11:06 --> 00:11:09 possibly is that
00:11:09 --> 00:11:12 maybe there was a collision.
00:11:12 --> 00:11:15 Uh, and we know that galaxies
00:11:15 --> 00:11:18 have grown by sort of gobbling up smaller
00:11:18 --> 00:11:20 galaxies. And if this collision
00:11:21 --> 00:11:23 took place at, uh, this high angle,
00:11:23 --> 00:11:26 uh, so that you've got a dwarf galaxy perhaps
00:11:26 --> 00:11:29 being absorbed by, uh, uh,
00:11:29 --> 00:11:32 NGC 4698, um,
00:11:32 --> 00:11:35 then you might very well get
00:11:35 --> 00:11:37 these velocities which are perpendicular to
00:11:37 --> 00:11:40 the disc of the galaxy. Um, we've
00:11:40 --> 00:11:43 got a similar situation in our own
00:11:43 --> 00:11:46 galaxy with the Two Magellanic Clouds,
00:11:46 --> 00:11:49 the dwarf galaxies. They're quite big for
00:11:49 --> 00:11:52 dwarf galaxies, actually. Uh, but they still
00:11:52 --> 00:11:54 count as that. Uh, they are visible in our
00:11:54 --> 00:11:57 southern hemisphere sky. They are being
00:11:57 --> 00:11:59 absorbed by our own galaxy. And there's a
00:11:59 --> 00:12:01 sort of something called the Magellanic, uh,
00:12:01 --> 00:12:04 stream, which is a stream of stars between
00:12:04 --> 00:12:06 them and connecting with the disc of our
00:12:06 --> 00:12:08 galaxy. And they're at a relatively high
00:12:08 --> 00:12:11 angle. So maybe in a few
00:12:12 --> 00:12:14 hundred million years, when space nuts will
00:12:14 --> 00:12:17 still be going, uh, we might have a
00:12:17 --> 00:12:19 similar phenomenon in our own galaxy. A bulge
00:12:20 --> 00:12:22 that's modified, that sticks up. Uh, although
00:12:22 --> 00:12:24 we've got a bar as well in the middle, which
00:12:24 --> 00:12:27 is a fairly robust feature. I think as
00:12:27 --> 00:12:30 the galaxy evolves, that will stay pretty
00:12:30 --> 00:12:32 solidly there. So we might end up with two
00:12:32 --> 00:12:32 bulges.
00:12:32 --> 00:12:33 Who knows?
00:12:33 --> 00:12:36 Andrew Dunkley: You never know. Yeah, so this one's, uh,
00:12:36 --> 00:12:39 quite, quite amazing. And, uh, uh, you
00:12:39 --> 00:12:41 can read all about it on the
00:12:41 --> 00:12:44 European Space agency website. That's
00:12:44 --> 00:12:47 ESA.int and just do
00:12:47 --> 00:12:49 a search for, uh, NGC
00:12:49 --> 00:12:52 4698, I think, would be probably the easiest
00:12:52 --> 00:12:53 thing to do, Fred Watson.
00:12:53 --> 00:12:56 Professor Fred Watson: Yeah, Or, I mean, the title of their press
00:12:56 --> 00:12:59 release is lovely. A Galaxy Spinning out of
00:12:59 --> 00:13:00 Sink. I like that.
00:13:00 --> 00:13:01 Andrew Dunkley: Yes.
00:13:01 --> 00:13:01 Professor Fred Watson: Yeah.
00:13:01 --> 00:13:03 Andrew Dunkley: Or it fell down a sink or something.
00:13:04 --> 00:13:06 Those tend to spiral as well.
00:13:06 --> 00:13:08 Professor Fred Watson: Yes, well, they do. That's right. Yeah.
00:13:08 --> 00:13:09 Andrew Dunkley: Indeed.
00:13:09 --> 00:13:10 Professor Fred Watson: Two different sinks.
00:13:11 --> 00:13:13 Andrew Dunkley: Have a look for it. Uh, this is Space Nuts
00:13:13 --> 00:13:15 with Andrew Dunkley and Professor Fred Watson
00:13:15 --> 00:13:18 Watson. Okay, we've had a problem here.
00:13:18 --> 00:13:19 Professor Fred Watson: This is Houston. Say again, please.
00:13:20 --> 00:13:21 Professor Fred Watson: We've had a problem.
00:13:21 --> 00:13:23 Professor Fred Watson: We've had a B pup on a vault.
00:13:24 --> 00:13:26 So we're looking at it.
00:13:26 --> 00:13:29 Andrew Dunkley: Space Muffs. And I've got to say
00:13:29 --> 00:13:31 hello to a couple of our live viewers.
00:13:31 --> 00:13:34 Uh, Emily is, uh, watching us from a
00:13:34 --> 00:13:37 taxi in Perth at the moment on her way to a
00:13:37 --> 00:13:39 conference or a training course, I think.
00:13:40 --> 00:13:42 And, uh, yeah, so, um, yeah, the
00:13:42 --> 00:13:45 places we tune in from, I guess we're all
00:13:45 --> 00:13:47 nuts. She says, hi
00:13:47 --> 00:13:48 Emily.
00:13:48 --> 00:13:51 And, uh, Sophie's listening to us, uh, from,
00:13:51 --> 00:13:54 uh. Now, where did she say? Doesn't, uh,
00:13:54 --> 00:13:56 say where she's from, but she does ask if
00:13:56 --> 00:13:59 we'd heard about the potential closure of the
00:13:59 --> 00:14:01 Jodrell bank facility. Oh, she's in
00:14:01 --> 00:14:04 Somerset in the uk. Hi, Sophie. Yes, we, we
00:14:04 --> 00:14:06 were very much aware of that. That's been
00:14:06 --> 00:14:07 brought to our attention by a couple of
00:14:07 --> 00:14:10 listeners recently. Yes, and very
00:14:10 --> 00:14:12 sad news. Very sad news indeed.
00:14:13 --> 00:14:16 Professor Fred Watson: Except that we think it's been the, the, the
00:14:16 --> 00:14:17 prime. The Prime Minister mentioned it in
00:14:17 --> 00:14:20 Parliament about two weeks ago, saying that,
00:14:21 --> 00:14:23 uh, every school kid of his generation
00:14:23 --> 00:14:25 went to visit Jodrell bank and there's no way
00:14:25 --> 00:14:27 he was going to see it being closed in his
00:14:27 --> 00:14:27 watch.
00:14:28 --> 00:14:30 Andrew Dunkley: That's good news. There you go, Sophie. So,
00:14:30 --> 00:14:33 um, it may well be saved. Yeah, that
00:14:33 --> 00:14:34 would be wonderful.
00:14:35 --> 00:14:37 Um, lovely to have a live audience. It's
00:14:37 --> 00:14:38 becoming a new trend for us.
00:14:38 --> 00:14:40 Professor Fred Watson: Isn't it great? Yeah, it's absolutely
00:14:40 --> 00:14:41 fantastic.
00:14:41 --> 00:14:44 Andrew Dunkley: Terrific. Let's go to our next story,
00:14:44 --> 00:14:47 and this one's a little bit weird,
00:14:47 --> 00:14:49 and I'll try and pronounce this correctly,
00:14:49 --> 00:14:51 but we're talking about an object named
00:14:52 --> 00:14:55 Carricklo. Uh, now, um,
00:14:55 --> 00:14:58 the story is about the rings around
00:14:58 --> 00:15:01 Chariklo that are. That are changing. But
00:15:01 --> 00:15:03 we better firstly explain what this
00:15:03 --> 00:15:05 object actually is.
00:15:06 --> 00:15:09 Professor Fred Watson: Uh, yes, that's a, uh, nice way to
00:15:09 --> 00:15:11 introduce the story because, um, Chariklo is
00:15:11 --> 00:15:13 not one that we talk about very much.
00:15:13 --> 00:15:16 Uh, its full name is one zero one. Um, nine.
00:15:16 --> 00:15:18 Nine Chariklo. And the fact that it's
00:15:18 --> 00:15:20 preceded by a number tells you that it's an
00:15:20 --> 00:15:22 asteroid. Uh, uh,
00:15:22 --> 00:15:25 every asteroid, uh, has a number as well as a
00:15:25 --> 00:15:27 name like 5691. Fred Watson Watson.
00:15:28 --> 00:15:31 Sorry, couldn't resist it. So
00:15:31 --> 00:15:33 10199 curriculo. Um, but
00:15:33 --> 00:15:36 it's not, uh, an asteroid. Ah, Fred Watson
00:15:36 --> 00:15:38 Watson, by the way, is probably the single
00:15:38 --> 00:15:40 most boring object in the solar system.
00:15:41 --> 00:15:44 It is in the main asteroid belt. It never
00:15:44 --> 00:15:46 does anything, uh, just sort of circulates
00:15:46 --> 00:15:48 around the sun. Um, there's not really
00:15:48 --> 00:15:50 anything to, you know, to make it stand out
00:15:50 --> 00:15:53 and it definitely won't hit the Earth anytime
00:15:53 --> 00:15:54 soon. Uh,
00:15:55 --> 00:15:57 Cariklo, on the other hand.
00:15:57 --> 00:15:59 Andrew Dunkley: Wouldn't it be ironic though if it hit Earth
00:15:59 --> 00:16:00 and hit your house?
00:16:03 --> 00:16:05 Professor Fred Watson: I probably told you this story before when
00:16:06 --> 00:16:08 more than 20 years ago now, when it was
00:16:08 --> 00:16:11 announced that the IAU was naming an
00:16:11 --> 00:16:13 asteroid after me. I went home from the
00:16:13 --> 00:16:16 observatory, told my two young sons that
00:16:16 --> 00:16:18 that was what had happened. They said, dad,
00:16:18 --> 00:16:20 that was terrible. If it hits the Earth,
00:16:20 --> 00:16:22 it'll be your fault. Um, and, um.
00:16:23 --> 00:16:25 So, yes, I've had that hanging over my head,
00:16:25 --> 00:16:27 uh, ever since. It will never, ever hit the
00:16:27 --> 00:16:29 Earth. The dynamics of the solar system are
00:16:29 --> 00:16:32 such that it will remain, as I said, probably
00:16:32 --> 00:16:34 the single most boring object in the entire
00:16:34 --> 00:16:36 solar system. Unlike Curriculo, um,
00:16:36 --> 00:16:39 which, uh, is, uh. Actually,
00:16:39 --> 00:16:40 it's called a centaur.
00:16:41 --> 00:16:44 That's a class of asteroids and this
00:16:44 --> 00:16:45 is the biggest of them. Curriculo. It's
00:16:45 --> 00:16:48 probably 250 kilometres across itself. A
00:16:48 --> 00:16:51 large ish asteroid. Um, and they
00:16:51 --> 00:16:53 orbit, uh, between the orbits of Saturn
00:16:54 --> 00:16:56 and Uranus. Uh, ah,
00:16:56 --> 00:16:59 that's the centaurs. Uh, this particular one,
00:16:59 --> 00:17:02 Chariklo, has an orbital period of
00:17:02 --> 00:17:04 62 and a half years. That's how long it takes
00:17:04 --> 00:17:07 to go around. Once actually discovered back
00:17:07 --> 00:17:09 in the 1990s at Kitt Peak National
00:17:09 --> 00:17:12 Observatory in Arizona. Uh, it's
00:17:12 --> 00:17:15 got a, uh, dark reddish surface.
00:17:15 --> 00:17:18 Um, uh, uh, this brief
00:17:19 --> 00:17:21 update comes from Wikipedia just
00:17:21 --> 00:17:24 so I can get all the facts in there. It's got
00:17:24 --> 00:17:26 water, ice, silicate minerals, amorphous
00:17:26 --> 00:17:29 carbon and various complex organic
00:17:29 --> 00:17:32 compounds known as solins. Actually, uh, so
00:17:32 --> 00:17:34 these are the things that make
00:17:35 --> 00:17:38 many of those very distant trans. Neptunian
00:17:38 --> 00:17:40 objects, like, um,
00:17:40 --> 00:17:42 our old friend Arrokoth, the most distant
00:17:42 --> 00:17:44 object that's yet been visited by a
00:17:44 --> 00:17:47 spacecraft. Quite a, uh, reddish reddy
00:17:47 --> 00:17:48 brown surface.
00:17:49 --> 00:17:51 Andrew Dunkley: Yeah, SEDNA is like that too, apparently.
00:17:52 --> 00:17:55 Professor Fred Watson: That's right, yeah. It's common. It
00:17:55 --> 00:17:57 comes about because of the, uh,
00:17:58 --> 00:18:01 um, bombardment by
00:18:01 --> 00:18:04 subatomic particles from the sun and also
00:18:04 --> 00:18:06 cosmic rays, which come from outside the
00:18:06 --> 00:18:09 solar system, uh, over, uh, many billions
00:18:09 --> 00:18:11 of years. Like the four billion year history
00:18:11 --> 00:18:13 of the solar system. A four and a half
00:18:13 --> 00:18:16 billion year history. Um, and that modifies
00:18:16 --> 00:18:18 these chemicals to give you this brownish
00:18:18 --> 00:18:20 colour. So, um,
00:18:21 --> 00:18:24 there are, uh, uh, rings around
00:18:24 --> 00:18:26 Curriculo. I think it may have a
00:18:26 --> 00:18:29 moon. Um, I have that
00:18:29 --> 00:18:32 wrong, but it certainly has
00:18:33 --> 00:18:33 rings.
00:18:34 --> 00:18:37 Uh, maybe it doesn't have a moon. Sorry, M. I
00:18:37 --> 00:18:38 don't want to mislead anybody.
00:18:38 --> 00:18:41 Andrew Dunkley: Um, I'll tell you in a second. No,
00:18:42 --> 00:18:44 it does not have a confirmed moon yet,
00:18:45 --> 00:18:46 is the answer.
00:18:46 --> 00:18:48 Professor Fred Watson: Yeah, well, that's right. It's a long way
00:18:48 --> 00:18:50 away. It's beyond the orbit of Saturn.
00:18:51 --> 00:18:53 An object only a couple of hundred kilometres
00:18:53 --> 00:18:55 across, uh, smallish object.
00:18:56 --> 00:18:59 Um, uh, but it's got
00:18:59 --> 00:19:02 rings. And uh, how do we know that?
00:19:02 --> 00:19:05 By this marvellous technique, uh, that I
00:19:05 --> 00:19:07 always think is a great way to find solar
00:19:07 --> 00:19:09 system objects and measure them. Sometimes
00:19:10 --> 00:19:12 what we call occultations. When,
00:19:12 --> 00:19:15 uh, a solar system object passes in front
00:19:15 --> 00:19:18 of uh, a distant star and
00:19:18 --> 00:19:20 so its light is blocked, the light of the
00:19:20 --> 00:19:22 star is blocked. And if you have enough
00:19:22 --> 00:19:25 people observing the occultation, you spread
00:19:25 --> 00:19:27 them out across, well, sometimes across a
00:19:27 --> 00:19:29 nation like Australia, uh,
00:19:30 --> 00:19:33 you can essentially uh,
00:19:33 --> 00:19:36 see the dip in light, uh,
00:19:36 --> 00:19:39 and map it. Map m whatever it is that's uh,
00:19:39 --> 00:19:42 obscuring over uh, this area
00:19:42 --> 00:19:44 of the land where you've got observers.
00:19:45 --> 00:19:47 So you get all the observers to
00:19:48 --> 00:19:51 time when the background star
00:19:51 --> 00:19:53 seems to disappear and reappear. And by
00:19:53 --> 00:19:56 doing that, by plotting all those timings
00:19:56 --> 00:19:59 on a map, you can actually get the shape of
00:19:59 --> 00:20:01 whatever it is that's occulting or blocking
00:20:01 --> 00:20:04 out the light of the star. And back in
00:20:04 --> 00:20:06 2013, uh, Kuriklo,
00:20:06 --> 00:20:09 uh occulted a star and it
00:20:09 --> 00:20:12 was seen that there were
00:20:12 --> 00:20:15 sort of symmetric occultations on either side
00:20:15 --> 00:20:18 of the main object which tell you that you've
00:20:18 --> 00:20:20 got rings. So
00:20:21 --> 00:20:24 that's the backstory. Uh, the front
00:20:24 --> 00:20:26 story is that uh,
00:20:26 --> 00:20:29 curricula has now been observed or
00:20:29 --> 00:20:31 occultations have now been
00:20:31 --> 00:20:34 observed by the James Webb Telescope, which
00:20:34 --> 00:20:36 of course is a very powerful instrument.
00:20:36 --> 00:20:38 And so you get very, very sensitive light
00:20:38 --> 00:20:41 curves or very detailed light curves. And
00:20:41 --> 00:20:44 what they're finding is, uh, that its
00:20:44 --> 00:20:45 rings have changed.
00:20:47 --> 00:20:49 They've changed significantly since that
00:20:50 --> 00:20:53 um, 2013 discovery.
00:20:54 --> 00:20:57 Uh, um, it
00:20:57 --> 00:20:59 basically uh, is a very nice
00:20:59 --> 00:21:01 occultation because it misses the
00:21:02 --> 00:21:05 curricula itself. Curricula, uh, didn't dim
00:21:05 --> 00:21:08 the star, uh, because the
00:21:08 --> 00:21:10 line of sight to the star from the James Webb
00:21:10 --> 00:21:13 telescope was uh, about seven kilometres
00:21:13 --> 00:21:15 above the Curriculo's surface. We're talking
00:21:15 --> 00:21:18 in very small distances here. So that the
00:21:18 --> 00:21:21 rings of Curriculo, and I didn't mention that
00:21:21 --> 00:21:23 there are two, not just one, there are two,
00:21:23 --> 00:21:26 uh, which crossed, uh, passed in
00:21:26 --> 00:21:29 front of the star, uh, and uh, were
00:21:29 --> 00:21:32 able to be measured um, by
00:21:32 --> 00:21:34 the James Webb Space Telescope. Some very
00:21:34 --> 00:21:37 nice observations, uh, of that. And
00:21:38 --> 00:21:41 uh, what we now know, uh, is
00:21:41 --> 00:21:44 that the rings have changed, as I said, since
00:21:44 --> 00:21:47 20. Um, and so what
00:21:47 --> 00:21:50 we've got is a darkening of
00:21:50 --> 00:21:52 the inner ring, uh
00:21:53 --> 00:21:56 m sort of more so than would be
00:21:56 --> 00:21:58 expected. Uh, there have been other
00:21:58 --> 00:22:01 observations since 2013, uh, in 2014
00:22:01 --> 00:22:04 and 2017. Um, so
00:22:04 --> 00:22:07 these, you know, uh, the observations allow
00:22:07 --> 00:22:10 uh, us to see the way things uh,
00:22:10 --> 00:22:13 change. The astronomers who've done
00:22:13 --> 00:22:15 this work do make the comment though
00:22:16 --> 00:22:19 that maybe these rings are unequal in
00:22:19 --> 00:22:22 density. Uh, so if you've got, you know, the
00:22:22 --> 00:22:24 rings are made of material, just
00:22:24 --> 00:22:27 dusty material, uh, in orbit around the
00:22:27 --> 00:22:30 parent star. Uh, but there can be regions
00:22:30 --> 00:22:32 where there's more dust than there is further
00:22:32 --> 00:22:35 along the ring. And so it may be
00:22:35 --> 00:22:38 that uh, we've, you know, that
00:22:39 --> 00:22:41 they, that's what they've seen, a more dense
00:22:41 --> 00:22:44 region. Uh, but um, doing a
00:22:44 --> 00:22:46 statistical um, analysis of that
00:22:47 --> 00:22:49 suggests that that's probably not the case.
00:22:49 --> 00:22:51 That it probably is a real effect
00:22:52 --> 00:22:54 that the rings are actually
00:22:55 --> 00:22:57 um, that you know, the rings themselves are
00:22:58 --> 00:22:59 changing in structure.
00:22:59 --> 00:23:02 Andrew Dunkley: Yeah. Interestingly Fred Watson, we
00:23:02 --> 00:23:05 mentioned um, earlier about whether or not it
00:23:05 --> 00:23:07 had a moon. There is a hidden moon
00:23:07 --> 00:23:10 hypothesis, uh. Ah, yes, attached to this
00:23:10 --> 00:23:13 uh, object. And um, uh, some
00:23:13 --> 00:23:15 astronomers believe a tiny moon about two
00:23:15 --> 00:23:18 miles across, three kilometres, ish,
00:23:19 --> 00:23:21 uh, is orbiting inside or near the
00:23:21 --> 00:23:24 rings. And its gravity acts like
00:23:24 --> 00:23:27 a sheepdog, cosmic sheepdog they say,
00:23:27 --> 00:23:29 containing the icy particles so the rings
00:23:29 --> 00:23:31 stay intact. That's one theory,
00:23:32 --> 00:23:33 yes.
00:23:33 --> 00:23:35 Professor Fred Watson: Uh, and
00:23:36 --> 00:23:36 um,
00:23:39 --> 00:23:41 certainly um, this research
00:23:42 --> 00:23:44 uh, mentions that partly because
00:23:45 --> 00:23:48 um, there are resonances here and we've
00:23:48 --> 00:23:50 talked about resonances before. When you've
00:23:50 --> 00:23:53 got one thing that orbits, for
00:23:53 --> 00:23:54 example, um.
00:23:54 --> 00:23:57 Well, if you've got moons orbiting like
00:23:57 --> 00:23:59 Saturn as resonances, one moon will
00:23:59 --> 00:24:02 orbit uh, twice for
00:24:02 --> 00:24:04 another moon going around three times. These
00:24:04 --> 00:24:07 are uh, what we call resonances. And
00:24:09 --> 00:24:12 apparently uh, one of the rings is a uh, one
00:24:12 --> 00:24:15 to three resonance with curricula itself.
00:24:15 --> 00:24:17 So you've got a ring particle going around
00:24:17 --> 00:24:20 once for every three rotations of
00:24:20 --> 00:24:23 curricula. And that could shape the
00:24:23 --> 00:24:25 structure of the rings. Um, but
00:24:25 --> 00:24:28 that in itself might be caused, exactly as
00:24:28 --> 00:24:30 you've just said, by what they call a
00:24:30 --> 00:24:32 shepherd satellite. An unseen moon
00:24:33 --> 00:24:35 could perhaps uh, help to keep the
00:24:35 --> 00:24:38 ring intact. Uh, exactly as we
00:24:38 --> 00:24:41 see in some of the tiny moons of Saturn,
00:24:41 --> 00:24:43 which are almost embedded in Saturn's ring
00:24:43 --> 00:24:45 system. So yeah, this is um,
00:24:46 --> 00:24:49 really interesting stuff. Uh, if you're an
00:24:49 --> 00:24:51 asteroid fanatic, uh, um,
00:24:52 --> 00:24:54 with these possibilities, um, imagine what
00:24:54 --> 00:24:56 something like that would look like if you
00:24:56 --> 00:24:58 could stand close to it. Because curricula
00:24:58 --> 00:25:00 itself is probably a fairly irregular object.
00:25:00 --> 00:25:02 It is big enough to be more or less
00:25:02 --> 00:25:05 spherical, but um, we don't know its true
00:25:05 --> 00:25:07 shape. That's something else that can be
00:25:07 --> 00:25:08 gained by the way, by occultation
00:25:08 --> 00:25:09 measurements.
00:25:10 --> 00:25:10 Professor Fred Watson: Mhm.
00:25:10 --> 00:25:13 Andrew Dunkley: The other interesting thing is um,
00:25:13 --> 00:25:16 the belief is those rings will disperse
00:25:16 --> 00:25:16 eventually.
00:25:18 --> 00:25:20 Professor Fred Watson: Yeah, exactly as we think with Saturn. Ah,
00:25:21 --> 00:25:24 but I think these might have a relatively
00:25:24 --> 00:25:25 short timescale. I can't remember what sort
00:25:25 --> 00:25:26 of timescale.
00:25:27 --> 00:25:28 Andrew Dunkley: Uh, a few million years
00:25:30 --> 00:25:32 Is the, the theory.
00:25:32 --> 00:25:34 Professor Fred Watson: Relatively short. Saturn's rings are expected
00:25:35 --> 00:25:38 to disperse within the next hundred million
00:25:38 --> 00:25:40 years or so. It's in the diary. I've got it
00:25:40 --> 00:25:41 in my diary. I hope you have too.
00:25:42 --> 00:25:45 Andrew Dunkley: Uh, yes, I have, yes. Um, when they say
00:25:45 --> 00:25:46 disperse, what does that mean? They're just
00:25:46 --> 00:25:48 going to go drifting off into space.
00:25:48 --> 00:25:51 Professor Fred Watson: And probably in um, maybe,
00:25:51 --> 00:25:54 I suspect in both cases it will be a question
00:25:54 --> 00:25:56 of them collapsing onto the, gradually
00:25:56 --> 00:25:59 collapsing onto the surface of the body
00:25:59 --> 00:26:02 itself. We know that um, the inner edge
00:26:02 --> 00:26:05 of Saturn's rings are uh, basically raining
00:26:05 --> 00:26:07 down into Saturn. We saw that with the
00:26:07 --> 00:26:09 Cassini spacecraft. Direct evidence of that.
00:26:10 --> 00:26:12 A kind of rainfall of ice
00:26:13 --> 00:26:16 from the inner edge of the rings, uh,
00:26:16 --> 00:26:18 heading down towards the planet. And I
00:26:18 --> 00:26:20 suspect that's what will happen with
00:26:20 --> 00:26:22 Curriculo. Uh, the rings will end up on the
00:26:22 --> 00:26:24 surface. We think, and you and I have covered
00:26:24 --> 00:26:27 this on space knots, there might be evidence
00:26:27 --> 00:26:29 that the same thing happened on Earth
00:26:29 --> 00:26:30 billions of years ago.
00:26:31 --> 00:26:34 Andrew Dunkley: Interesting. If you'd like to read all about
00:26:34 --> 00:26:36 it, you can find out about uh,
00:26:36 --> 00:26:38 Curriculo's rings on the
00:26:38 --> 00:26:41 Brighterside News website.
00:26:42 --> 00:26:44 This is Space Nuts. Andrew Dunkley here,
00:26:45 --> 00:26:46 Fred Watson Watson there.
00:26:49 --> 00:26:50 Professor Fred Watson: Amen.
00:26:50 --> 00:26:51 Professor Fred Watson: Space Nuts.
00:26:52 --> 00:26:55 Andrew Dunkley: Now Fred Watson, we turn our attention to the
00:26:55 --> 00:26:58 JUICE mission. This is an ESA mission to
00:26:58 --> 00:27:01 Jupiter, uh, to look at its uh,
00:27:01 --> 00:27:04 it's moons and uh, it's about
00:27:04 --> 00:27:07 to do something. By the time this podcast is
00:27:07 --> 00:27:09 out, um, Juice will have done the, something
00:27:09 --> 00:27:11 that we're talking about doing.
00:27:11 --> 00:27:13 Professor Fred Watson: Right? It will, it'll have
00:27:13 --> 00:27:16 done it, it'll have done its thing and uh,
00:27:16 --> 00:27:18 uh, successfully, we hope so. Juice, uh,
00:27:18 --> 00:27:21 it's a really juicy topic of course. We can't
00:27:21 --> 00:27:23 resist, uh, that. I uh, had a nice glass of
00:27:23 --> 00:27:25 orange juice a couple of hours ago as well,
00:27:25 --> 00:27:26 which was good.
00:27:26 --> 00:27:29 Anyway, um, it's um, uh, it is
00:27:29 --> 00:27:31 the European Space Agency's Jupiter
00:27:31 --> 00:27:34 Icy Moons Explorer. That's where the name
00:27:34 --> 00:27:37 comes from. Uh, and uh, it's heading for
00:27:37 --> 00:27:39 Jupiter. Uh, if I remember rightly, it
00:27:39 --> 00:27:42 will orbit the planet itself, making
00:27:42 --> 00:27:45 frequent flybys. Um,
00:27:46 --> 00:27:49 uh, there is NASA's probe which is also
00:27:50 --> 00:27:53 uh, looking at the ice moons. Uh,
00:27:54 --> 00:27:56 that is Europa Clipper, that's called.
00:27:56 --> 00:27:57 Andrew Dunkley: That's right, yeah.
00:27:57 --> 00:28:00 Professor Fred Watson: That will also be in orbit around
00:28:00 --> 00:28:02 Jupiter. Anyway, Juice, um, is
00:28:03 --> 00:28:06 heading out to Jupiter but it's been on its
00:28:06 --> 00:28:08 way there for three and a half years. Uh,
00:28:08 --> 00:28:11 and um, given that it was
00:28:11 --> 00:28:14 launched in April 2023, uh, in
00:28:14 --> 00:28:17 French Guiana. That's where, uh, the
00:28:17 --> 00:28:19 ESA Space Port is. And
00:28:20 --> 00:28:22 what it's done in the time since
00:28:22 --> 00:28:25 then. Uh, first of all, it did,
00:28:26 --> 00:28:29 uh, a lunar Earth flyby. Um,
00:28:29 --> 00:28:31 in other words, kind of taking
00:28:31 --> 00:28:34 the gravitational pull of both the Moon and
00:28:34 --> 00:28:37 the Earth into account. Uh, then
00:28:37 --> 00:28:39 it did a Venus flyby and you think, wait a
00:28:39 --> 00:28:41 minute, Venus isn't on the way to Jupiter.
00:28:42 --> 00:28:43 It's the other way.
00:28:43 --> 00:28:44 Andrew Dunkley: Here we go again.
00:28:44 --> 00:28:46 Professor Fred Watson: Yeah, here we go again. But that's how you do
00:28:46 --> 00:28:49 these gravitational assists, uh, that um,
00:28:49 --> 00:28:51 actually increased its speed. Uh,
00:28:52 --> 00:28:54 and I think I'm right in saying as we stand
00:28:54 --> 00:28:57 here now, there are two more flybys of Earth.
00:28:57 --> 00:29:00 Uh, one on the 28th of September,
00:29:01 --> 00:29:03 um, which is as we're speaking now in the
00:29:03 --> 00:29:05 future, but perhaps won't be by the time our
00:29:05 --> 00:29:07 listeners hear this, except for our live
00:29:07 --> 00:29:09 audience who are hearing it now. Um, and
00:29:09 --> 00:29:10 welcome again.
00:29:11 --> 00:29:14 Andrew Dunkley: By the time this one goes out, this episode
00:29:14 --> 00:29:15 goes out, what we're talking about will have
00:29:15 --> 00:29:16 happened last week.
00:29:17 --> 00:29:19 Professor Fred Watson: Okay, so last week there was another flyby
00:29:20 --> 00:29:23 of the Earth, um, coming
00:29:23 --> 00:29:26 within, uh, actually less than 9
00:29:26 --> 00:29:28 kilometres of the Earth's surface. That is
00:29:28 --> 00:29:31 very close. Uh, and that sets it
00:29:31 --> 00:29:34 up for a, uh, gravitational.
00:29:34 --> 00:29:37 Final gravitational assist in January
00:29:37 --> 00:29:40 2029. A, uh, couple of
00:29:40 --> 00:29:42 years down the track, three years down the
00:29:42 --> 00:29:44 track, um, or two and a half. Um,
00:29:45 --> 00:29:47 and that will put Juice on its,
00:29:48 --> 00:29:51 uh, sort of, um. I guess the
00:29:51 --> 00:29:53 best way to describe it is on the
00:29:53 --> 00:29:55 fastest part of its journey because it will
00:29:55 --> 00:29:58 then head off towards Jupiter, uh, and
00:29:58 --> 00:30:01 intercepting the orbit of Jupiter in July
00:30:01 --> 00:30:04 2031. Uh, so a long
00:30:04 --> 00:30:06 and complicated journey. Still simple
00:30:06 --> 00:30:09 compared with BepiColombo, uh, which is now
00:30:09 --> 00:30:11 in the region of Mercury after I think. Was
00:30:11 --> 00:30:13 it eight or nine gravitational assists?
00:30:13 --> 00:30:14 Andrew Dunkley: It was nine. Yeah.
00:30:14 --> 00:30:17 Professor Fred Watson: Nine. Yeah. Um, so, uh,
00:30:18 --> 00:30:21 it's actually um, one of these things
00:30:21 --> 00:30:24 that uh, uh, we almost
00:30:24 --> 00:30:26 certainly won't notice it. Uh, but
00:30:26 --> 00:30:29 at that height, uh, it's uh,
00:30:29 --> 00:30:32 possible that people who know
00:30:32 --> 00:30:35 how to find the trajectory in the sky
00:30:36 --> 00:30:39 using, uh, telescopes or even binoculars
00:30:39 --> 00:30:41 might be able to track it. And there is a
00:30:41 --> 00:30:43 link on the European Space
00:30:43 --> 00:30:46 Agency's, uh, media
00:30:46 --> 00:30:49 brief on this, a link to tell you how to find
00:30:49 --> 00:30:52 the trajectory. So, uh, head
00:30:52 --> 00:30:54 to, uh, the page called Juice to fly past
00:30:54 --> 00:30:57 Earth for a third gravity assist. Uh,
00:30:58 --> 00:31:01 which might have been revised to Juice flew
00:31:01 --> 00:31:03 past Earth for a third gravity assist.
00:31:03 --> 00:31:04 Andrew Dunkley: It might.
00:31:05 --> 00:31:07 Professor Fred Watson: In which case you don't need to know where
00:31:07 --> 00:31:09 its trajectory is. But anybody who's
00:31:09 --> 00:31:11 listening live now can find that trajectory
00:31:11 --> 00:31:12 data on that website.
00:31:12 --> 00:31:13 I think there's at least two people who are
00:31:13 --> 00:31:14 listening.
00:31:15 --> 00:31:16 Andrew Dunkley: It's a very exciting mission.
00:31:16 --> 00:31:19 Professor Fred Watson: Can't wait. It is, isn't it? Yeah.
00:31:19 --> 00:31:21 Andrew Dunkley: And, and such a complicated way to get
00:31:21 --> 00:31:23 somewhere. But, uh, probably no more
00:31:23 --> 00:31:25 complicated than catching suburban trains.
00:31:26 --> 00:31:29 So, um, you know, sometimes you have to
00:31:29 --> 00:31:31 go out there to get back there, but.
00:31:31 --> 00:31:33 Professor Fred Watson: Yeah, that's right. Yeah, indeed.
00:31:33 --> 00:31:35 Andrew Dunkley: But, yeah, yes, uh, it's on the ESA website
00:31:35 --> 00:31:38 if you want to check it out. The Juice
00:31:38 --> 00:31:41 mission. Um, yeah. Uh, and who
00:31:41 --> 00:31:43 knows what it will reveal? We just gotta be a
00:31:43 --> 00:31:43 bit patient.
00:31:43 --> 00:31:46 We've got a few more years to wait yet. That,
00:31:46 --> 00:31:48 uh, brings us to the end. Fred Watson, thank
00:31:48 --> 00:31:49 you very much.
00:31:50 --> 00:31:52 Professor Fred Watson: Uh, you're welcome, Andrew. It's been a joy
00:31:52 --> 00:31:54 to talk to you again and to our, uh,
00:31:54 --> 00:31:56 listeners and to the audience who will
00:31:56 --> 00:31:59 eventually see this, uh, long after Juice has
00:31:59 --> 00:31:59 come and gone.
00:32:00 --> 00:32:03 Andrew Dunkley: Yes, indeed, professor, um, Fred Watson
00:32:03 --> 00:32:05 Watson, astronomer at large, part of the team
00:32:05 --> 00:32:07 here at Space Nuts. Don't forget to visit our
00:32:07 --> 00:32:10 website. Uh, in the meantime, you can send us
00:32:10 --> 00:32:12 a message on the Ask me Anything link at the
00:32:12 --> 00:32:15 top that's labelled ama. Uh, you can check
00:32:15 --> 00:32:18 out the shop. Uh, you can, um,
00:32:18 --> 00:32:20 subscribe to the Astronomy newsletter
00:32:21 --> 00:32:23 or, or. And, uh, you can, um,
00:32:24 --> 00:32:25 do something else that I've completely
00:32:25 --> 00:32:28 forgotten about. Hate it
00:32:28 --> 00:32:31 when that happens. Anyway,
00:32:31 --> 00:32:33 and thanks to Huw in the studio who couldn't
00:32:33 --> 00:32:36 be with us today. He, um, he
00:32:36 --> 00:32:38 grabbed some juice and now he's
00:32:38 --> 00:32:41 156.7 million kilometres away.
00:32:41 --> 00:32:44 He'll be back next week and from me, Dunkley,
00:32:44 --> 00:32:45 thanks for your company.
00:32:45 --> 00:32:47 We'll see you on the next episode of Space
00:32:47 --> 00:32:47 Nuts.
00:32:47 --> 00:32:48 Professor Fred Watson: Bye.
00:32:48 --> 00:32:48 Andrew Dunkley: Bye.