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Show Notes
Cosmic Queries: Expanding Universe, Space Elevators, and TOI 6894B
In this enlightening Q&A episode of Space Nuts, hosts Andrew Dunkley and Professor Jonti Horner tackle a variety of intriguing questions from listeners, diving deep into the mysteries of the universe. From the nuances of cosmic expansion to the potential of space elevators and the peculiarities of exoplanets, this episode is packed with cosmic curiosities and insightful discussions that will expand your understanding of the cosmos.
Episode Highlights:
- The Acceleration of Cosmic Expansion: Rusty from Western Australia asks about the terminology for the increasing acceleration of the universe's expansion. Andrew and Jonti discuss the complexities of this concept, the implications of dark energy, and the evolving nature of cosmological theories.
- Space Elevators Explained: Barry's inquiry about the gravitational effects of a hypothetical space elevator prompts a detailed exploration of how gravity would be felt at various altitudes. The hosts discuss the feasibility of such a structure and the science behind gravity in different orbital scenarios.
- Understanding TOI 6894B: Casey from Colorado wants to know why TOI 6894B is significant. Andrew and Jonti delve into the characteristics of this unusual exoplanet, its relationship with its low-mass star, and what its discovery means for our understanding of planet formation and the diversity of planetary systems.
- Life in Gale Crater: A whimsical question from Philip McCrackpipe leads to a serious discussion about the potential for ancient life in Gale Crater on Mars. The hosts reflect on Mars' wet past and the types of life that may have thrived there, emphasizing the importance of ongoing exploration and research.
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Stay curious, keep looking up, and join us next time for more stellar insights and cosmic wonders. Until then, clear skies and happy stargazing.
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00:00:00 --> 00:00:03 Andrew Dunkley: Hello again. This is Space Nuts. It's a Q and
00:00:03 --> 00:00:05 A edition. This is where we take questions
00:00:05 --> 00:00:08 from the audience, throw them in the bin and
00:00:08 --> 00:00:10 discuss other things amongst ourselves. No,
00:00:10 --> 00:00:12 we do answer questions from the audience and
00:00:12 --> 00:00:14 we've got a bunch. Um, we've got a question
00:00:14 --> 00:00:17 about the uh, naming of the
00:00:17 --> 00:00:20 increase in the expansion of the universe
00:00:20 --> 00:00:23 rate. Although last episode, if you
00:00:23 --> 00:00:25 were listening, that might not be happening,
00:00:25 --> 00:00:27 but we will still try and tackle it. Uh,
00:00:27 --> 00:00:30 there's a question about space elevators.
00:00:30 --> 00:00:32 We've got uh, a question about an object that
00:00:32 --> 00:00:34 has been getting a lot of attention
00:00:34 --> 00:00:37 TOI6894B. And
00:00:37 --> 00:00:39 a very different kind of question, I
00:00:39 --> 00:00:42 will say, uh, regarding Gale Crater.
00:00:43 --> 00:00:45 That's all coming up on this, uh, edition of
00:00:45 --> 00:00:48 space nuts. 15 seconds. Guidance is
00:00:48 --> 00:00:51 internal. 10, 9.
00:00:51 --> 00:00:53 Ignition sequence start.
00:00:53 --> 00:00:55 Jonti Horner: Space nuts. 5, 4, 3, 2.
00:00:55 --> 00:00:58 Andrew Dunkley: 1. 2, 3, 4, 5, 5, 4, 3,
00:00:58 --> 00:01:01 2, 1. Space nuts. Astronauts report
00:01:01 --> 00:01:04 it feels good. He's back again for
00:01:04 --> 00:01:06 more. He is Jonti Horner, professor of
00:01:06 --> 00:01:08 Astrophysics at the University of Southern
00:01:08 --> 00:01:10 Queensland. Jonti, hello.
00:01:10 --> 00:01:12 Jonti Horner: Good afternoon. How are you going?
00:01:12 --> 00:01:14 Andrew Dunkley: I'm well, I'm very well.
00:01:14 --> 00:01:17 Uh, we've got a lot of questions and this
00:01:17 --> 00:01:19 very first one, we'll jump straight in. Comes
00:01:19 --> 00:01:22 from Rusty in Donnybrook in Western
00:01:22 --> 00:01:22 Australia.
00:01:22 --> 00:01:24 Andrew Dunkley: Johnny and Andrew. G'.
00:01:24 --> 00:01:24 Jonti Horner: Day.
00:01:24 --> 00:01:26 Andrew Dunkley: It's Rusty in Donnybrook and I'm wondering
00:01:26 --> 00:01:29 what the, the term um, for
00:01:30 --> 00:01:32 an increase in the acceleration
00:01:32 --> 00:01:35 rate for the expansion of the universe is.
00:01:35 --> 00:01:37 We've known about. Well we've had this
00:01:37 --> 00:01:39 concept for quite a few years now. And
00:01:39 --> 00:01:42 recently we um, we're now looking at
00:01:42 --> 00:01:44 a reduction in the acceleration of the
00:01:44 --> 00:01:46 expansion rate of the universe as well. So
00:01:46 --> 00:01:49 there's a positive and a negative aspect to
00:01:49 --> 00:01:51 this. And um, since we've had all this time,
00:01:51 --> 00:01:53 someone may have come up with ah, a better
00:01:53 --> 00:01:56 term than jolt or jerk, which seem
00:01:56 --> 00:01:59 to apply to very short term changes
00:01:59 --> 00:02:02 and not very gradual changes that
00:02:02 --> 00:02:05 we theorize uh, in the expansion of the
00:02:05 --> 00:02:07 universe. Thank you.
00:02:07 --> 00:02:10 Andrew Dunkley: Thanks Rusty. Always good to hear from you.
00:02:10 --> 00:02:11 Uh, he's always got a
00:02:12 --> 00:02:15 curveball type question, has Rusty. Although
00:02:15 --> 00:02:16 we might have been able to curve the ball
00:02:16 --> 00:02:19 back to him because last uh, episode we
00:02:19 --> 00:02:21 were talking about this very subject, the
00:02:21 --> 00:02:24 expand, increasing rate of the
00:02:24 --> 00:02:26 expansion of the universe. And uh, he wants
00:02:26 --> 00:02:29 to know what it should be called. But um, the
00:02:29 --> 00:02:31 expansion of the universe theory might be
00:02:31 --> 00:02:33 tipped on its head because of the research we
00:02:33 --> 00:02:35 were talking about last time. So if you
00:02:35 --> 00:02:37 haven't listened to the previous
00:02:37 --> 00:02:40 episode573, go back and have a Listen to
00:02:40 --> 00:02:42 the last story because it, it's
00:02:42 --> 00:02:45 suggesting that, uh, things may not be as
00:02:45 --> 00:02:46 they seem. Jonti.
00:02:47 --> 00:02:49 Jonti Horner: Absolutely. And it's, you know, this advert
00:02:49 --> 00:02:51 brought to you by the developing nature of
00:02:51 --> 00:02:54 science. Essentially it, uh, is how science
00:02:54 --> 00:02:56 evolves. You know, we get new observations
00:02:56 --> 00:02:58 and we revisit our theories. It's a really
00:02:58 --> 00:03:00 good question and it's a really good point. I
00:03:00 --> 00:03:02 have never actually heard any
00:03:02 --> 00:03:05 nickname or any kind of easy roll off
00:03:05 --> 00:03:07 the tongue phrase to talk about the
00:03:07 --> 00:03:09 accelerating expansion of the universe.
00:03:10 --> 00:03:12 Cosmologists talk about things in the context
00:03:12 --> 00:03:14 of the lambda CDM model. And, um, I don't
00:03:14 --> 00:03:16 really understand what that is because I'm
00:03:16 --> 00:03:18 not a cosmologist, but that is not an easy
00:03:18 --> 00:03:21 roll off the tongue nickname. Now, if you go
00:03:21 --> 00:03:23 back to the very, very, very, very early
00:03:23 --> 00:03:26 youth of the universe, there was
00:03:26 --> 00:03:29 a period where there was this incredibly
00:03:29 --> 00:03:32 accelerated expansion that is hypothesized
00:03:32 --> 00:03:34 called inflation. And, um, that was
00:03:35 --> 00:03:38 very, very, very early on. That's called the
00:03:38 --> 00:03:39 inflationary period. That's a little bit
00:03:39 --> 00:03:42 different. What Russ is talking about here is
00:03:42 --> 00:03:45 the, uh, evidence which won the Nobel
00:03:45 --> 00:03:48 Prize in 1998, I think, for the fact that,
00:03:48 --> 00:03:51 that the universe may be expanding at an
00:03:51 --> 00:03:53 accelerating rate. So in other words, the
00:03:53 --> 00:03:54 expansion is getting quicker rather than
00:03:54 --> 00:03:57 slowing down. And if gravity was winning,
00:03:57 --> 00:03:59 you'd expect the expansion to slow down over
00:03:59 --> 00:04:01 time as gravity pulls back on the expansion.
00:04:01 --> 00:04:04 So this was the great evidence for the
00:04:04 --> 00:04:05 existence of dark energy, which people
00:04:05 --> 00:04:08 hypothesize contributes something like
00:04:08 --> 00:04:11 68% of all that there is in the universe.
00:04:11 --> 00:04:13 It's basically we're a dark energy universe
00:04:13 --> 00:04:15 with a fair chunk of dark matter and a tiny
00:04:15 --> 00:04:17 little bit of normal matter on the side, like
00:04:17 --> 00:04:19 less than 2%. That,
00:04:20 --> 00:04:22 as we talked about in the previous episode,
00:04:22 --> 00:04:24 may be a paradigm that is about to change.
00:04:24 --> 00:04:26 There's growing evidence that the universe is
00:04:26 --> 00:04:29 perhaps a bit more complex than that. But in
00:04:29 --> 00:04:31 terms of Rusty's question, I have never come
00:04:31 --> 00:04:34 across a simple term or nickname
00:04:34 --> 00:04:37 or something like that for this theory.
00:04:37 --> 00:04:38 People just talk about the accelerating
00:04:38 --> 00:04:41 expansion rate of the universe. So
00:04:41 --> 00:04:43 unfortunately, Rusty, I can't help you there.
00:04:43 --> 00:04:45 To the best of my knowledge, there is no
00:04:45 --> 00:04:47 really snappy roll off your tongue thing. I.
00:04:48 --> 00:04:49 The model that tries to explain it, like,
00:04:49 --> 00:04:52 say, is a lambda CDM model. But that is
00:04:52 --> 00:04:54 not a snappy, um,
00:04:54 --> 00:04:57 public article, BBC documentary
00:04:57 --> 00:05:00 type name that will capture people's
00:05:00 --> 00:05:01 imaginations. That's just a working
00:05:02 --> 00:05:04 terminology in the industry kind of thing.
00:05:04 --> 00:05:04 Yeah.
00:05:04 --> 00:05:06 Andrew Dunkley: Well, while you've been talking, I asked
00:05:06 --> 00:05:09 Chatgpt what we
00:05:09 --> 00:05:11 should call it. It came up with a whole
00:05:11 --> 00:05:14 bunch, uh, accelerating universe hypothesis,
00:05:15 --> 00:05:17 uh, cosmic expansion theory, uh,
00:05:17 --> 00:05:20 inflation continuum theory, dark energy
00:05:20 --> 00:05:22 paradigm. You use that word. Uh,
00:05:23 --> 00:05:26 that's a more scientific style. But uh, it
00:05:26 --> 00:05:28 came up with some, uh, conceptual names. The
00:05:28 --> 00:05:31 great unbinding, uh,
00:05:31 --> 00:05:32 external expansion
00:05:33 --> 00:05:36 hypothesis, uh, runaway cosmos
00:05:36 --> 00:05:39 model, uh, the horizon drift
00:05:39 --> 00:05:41 theory. I like that one. Metric
00:05:41 --> 00:05:44 unfolding principle, the lambda drive and the
00:05:44 --> 00:05:47 everflight theory. That's what ChatGPT's come
00:05:47 --> 00:05:49 up with. Probably just found stuff that
00:05:49 --> 00:05:50 people have published.
00:05:50 --> 00:05:51 Jonti Horner: I think a lot of those are things that are
00:05:51 --> 00:05:53 linked to this but are other hypotheses and
00:05:53 --> 00:05:56 stuff like that. Yeah, I mean I have to admit
00:05:56 --> 00:05:58 that I didn't really want to Google things
00:05:58 --> 00:06:00 there because I wasn't all that keen on
00:06:00 --> 00:06:01 seeing the Google autocorrect coming back
00:06:01 --> 00:06:03 saying, did you mean expanding wasteland?
00:06:06 --> 00:06:08 Andrew Dunkley: Yeah, it does come up with some. Really what
00:06:08 --> 00:06:10 I hate is when I know exactly what I'm
00:06:10 --> 00:06:11 searching for. I put it in, I've uh, spelled
00:06:11 --> 00:06:13 it right and an autocorrect and finds me
00:06:13 --> 00:06:16 something else. Yeah, that's not what I asked
00:06:16 --> 00:06:18 for. I told you to look for, you know,
00:06:18 --> 00:06:21 lemonade, not lemons. Anyway,
00:06:22 --> 00:06:24 thanks Rusty. Uh, maybe you've got a name you
00:06:24 --> 00:06:26 can send through to us or maybe um, somebody
00:06:26 --> 00:06:28 could pose the question on the Facebook group
00:06:28 --> 00:06:31 or the podcast group on Facebook and uh,
00:06:31 --> 00:06:34 come up with some names. I'd be interested to
00:06:34 --> 00:06:36 see what you think of.
00:06:36 --> 00:06:38 Uh, our next question comes from Barry. Uh,
00:06:38 --> 00:06:41 Barry said, I, uh, recently read a sci fi
00:06:41 --> 00:06:44 book called First Ascent. Based on a space
00:06:44 --> 00:06:46 element. The elevator had six stations, one
00:06:46 --> 00:06:49 being Earth, uh, two at 300 kilometers, five
00:06:49 --> 00:06:52 at 6200 kilometers and six being
00:06:52 --> 00:06:53 geostationary orbit at
00:06:53 --> 00:06:56 35 kilometers. I
00:06:56 --> 00:06:58 know the International Space Station's about
00:06:58 --> 00:07:01 400 kilometers and the crew are in free
00:07:01 --> 00:07:04 fall. This is due to the forward motion of
00:07:04 --> 00:07:06 the iss, which is constantly falling and is
00:07:06 --> 00:07:09 in orbit. In the book they discuss that at
00:07:09 --> 00:07:12 Station 1 at 300 km the travellers are still
00:07:12 --> 00:07:15 at about 1G. Station 5, uh,
00:07:15 --> 00:07:18 at 6200 km they're at 1 quarter G,
00:07:18 --> 00:07:21 they're on the moon, they be at 1/6 and free
00:07:21 --> 00:07:24 fall, weightless, is at station 6,
00:07:24 --> 00:07:27 35 and a bit kilometers. Can you
00:07:27 --> 00:07:30 discuss with accuracy of feeling
00:07:30 --> 00:07:33 gravity if and when a space elevator is
00:07:33 --> 00:07:35 built? Of course, this is totally
00:07:35 --> 00:07:37 hypothetical for at least the next few
00:07:37 --> 00:07:40 hundred or thousand years. Yes it is. It's
00:07:40 --> 00:07:43 not something we can do yet. And even if we
00:07:43 --> 00:07:46 could, I don't know if it would be the
00:07:46 --> 00:07:49 Logical way to do things. But you know, we
00:07:49 --> 00:07:50 don't know what reasons in the future we
00:07:50 --> 00:07:53 might need one. So um, we'll just leave it
00:07:53 --> 00:07:54 hanging in the air. Boom.
00:07:54 --> 00:07:54 Jonti Horner: Boom.
00:07:55 --> 00:07:57 Andrew Dunkley: Um, so, uh, yeah. So can you discuss the
00:07:57 --> 00:08:00 accuracy of feeling gravity if and when a
00:08:00 --> 00:08:01 space.
00:08:01 --> 00:08:02 Jonti Horner: Uh, elevator is built?
00:08:03 --> 00:08:05 Yeah, it's a fabulous question. And it does
00:08:05 --> 00:08:08 sound like this book is hard sci fi in
00:08:08 --> 00:08:10 the sense that it's based on real world
00:08:10 --> 00:08:12 physics is what I'd say. It sounds like the
00:08:12 --> 00:08:14 numbers are right to me. Now the argument is
00:08:14 --> 00:08:16 that a space elevator, once you can get it
00:08:16 --> 00:08:18 built, it's an incredibly challenging thing
00:08:18 --> 00:08:20 to do beyond us at the minute. But once
00:08:20 --> 00:08:23 you've got it, it's suddenly it makes it much
00:08:23 --> 00:08:25 easier to access space. And part of the
00:08:25 --> 00:08:28 argument there is that we will be extracting
00:08:28 --> 00:08:31 resources off Earth. And so it's likely that
00:08:31 --> 00:08:32 there'll be more stuff coming down the
00:08:32 --> 00:08:34 elevator than going up. So effectively you
00:08:34 --> 00:08:37 can ride up for free, just, you know, as a
00:08:37 --> 00:08:39 side effect of it. So it's one of those
00:08:39 --> 00:08:42 things that has become a staple of kind of
00:08:42 --> 00:08:44 relatively near futureish science fiction.
00:08:45 --> 00:08:47 The numbers here about the acceleration that
00:08:47 --> 00:08:50 you'd feel are accurate. So there's two ways
00:08:50 --> 00:08:52 that you can get gravity if you're on a space
00:08:52 --> 00:08:55 elevator. One is that you would feel
00:08:55 --> 00:08:57 a pseudo gravity based on the acceleration
00:08:58 --> 00:09:01 of the lift going upwards. And you
00:09:01 --> 00:09:04 get this when your lift goes up or when it
00:09:04 --> 00:09:06 falls. If you're in a building that has one
00:09:06 --> 00:09:08 of those ultra fast lifts, you feel a little
00:09:08 --> 00:09:09 bit more weightless. If it's going down, you
00:09:09 --> 00:09:11 feel a little bit heavier when it's pulling
00:09:11 --> 00:09:13 up initially because the flow will be
00:09:13 --> 00:09:16 accelerating up to meet you or
00:09:16 --> 00:09:18 accelerating down away from you. And that
00:09:18 --> 00:09:21 will mean that you will get a change to the
00:09:21 --> 00:09:23 gravity you would otherwise feel if you were
00:09:23 --> 00:09:26 stationary at that altitude. So
00:09:26 --> 00:09:29 some sci fi books I've seen with kind of far
00:09:29 --> 00:09:31 future type technology have
00:09:32 --> 00:09:35 your space elevator, uh, able to accelerate,
00:09:35 --> 00:09:38 ah, or in excess of 1g, very hard
00:09:38 --> 00:09:40 acceleration. And what they do is they
00:09:40 --> 00:09:42 accelerate slowly going up through the
00:09:42 --> 00:09:44 atmosphere and then speed up once you're in
00:09:44 --> 00:09:46 vacuum with the acceleration
00:09:46 --> 00:09:49 offsetting the drop in gravity you get as you
00:09:49 --> 00:09:51 get higher, keeping you at a comfortable
00:09:51 --> 00:09:52 level of gravity. And then when you're
00:09:52 --> 00:09:55 halfway to the end point, it turns around,
00:09:55 --> 00:09:57 you have a brief period of pseudo
00:09:57 --> 00:09:59 weightlessness and then you accelerate in the
00:09:59 --> 00:10:01 other direction, slow down. So that's one way
00:10:01 --> 00:10:03 that you could get kind of constant gravity
00:10:03 --> 00:10:05 throughout almost the entire trip. And that
00:10:05 --> 00:10:07 will get you to your uh, End point pretty
00:10:07 --> 00:10:10 quickly. So if you're accelerating at 1G, you
00:10:10 --> 00:10:11 actually accelerate very quickly. And that's
00:10:11 --> 00:10:12 why you wait till you're out of the
00:10:12 --> 00:10:15 atmosphere to do that. But the other thing
00:10:15 --> 00:10:17 is, as you ride up on a space elevator, the
00:10:17 --> 00:10:20 higher you get, you will still feel gravity
00:10:20 --> 00:10:22 pulling you down through the soles of your
00:10:22 --> 00:10:25 feet, but the strength of the gravitational
00:10:25 --> 00:10:27 pull you feel will weaken. Now,
00:10:27 --> 00:10:30 when you're at the end point, which is
00:10:30 --> 00:10:33 a space station in geostationary orbit, you
00:10:33 --> 00:10:35 are moving around the Earth, ah, at orbital
00:10:35 --> 00:10:38 velocity. And, um, the space station around
00:10:38 --> 00:10:39 you is moving around the Earth at orbital
00:10:39 --> 00:10:42 velocity. So that's why you'd be weightless,
00:10:42 --> 00:10:44 because you're accelerating at exactly the
00:10:44 --> 00:10:46 same rate as your surroundings.
00:10:47 --> 00:10:50 So compared to you, there is no acceleration
00:10:50 --> 00:10:51 pulling you down because the flow's falling
00:10:51 --> 00:10:54 away at exactly the speed that you're falling
00:10:54 --> 00:10:56 down effectively. So that's what you'd
00:10:56 --> 00:10:58 experience very briefly if you were in an
00:10:58 --> 00:11:01 elevator on Earth and the wires were cut when
00:11:01 --> 00:11:03 you started to fall, you'd be weightless, but
00:11:03 --> 00:11:05 you wouldn't be enjoying the experience. No,
00:11:05 --> 00:11:06 not much worrying about what happens at the
00:11:06 --> 00:11:09 bottom. Although, thanks to a very, very
00:11:09 --> 00:11:12 silly TV series that's quite swearing
00:11:12 --> 00:11:14 offensive called Archer, my understanding is
00:11:14 --> 00:11:17 that lifts, uh, have been designed in such a
00:11:17 --> 00:11:19 way that if the cables break, there are
00:11:19 --> 00:11:21 safety mechanisms in so you won't just splat
00:11:21 --> 00:11:23 at the bottom. There was a whole episode
00:11:23 --> 00:11:24 based where they were stuck in the lift and
00:11:24 --> 00:11:26 they were worried about that. It's bizarre
00:11:26 --> 00:11:28 what you learn from random TV cartoons.
00:11:28 --> 00:11:31 Anyway, so you have,
00:11:31 --> 00:11:34 at the upper limit, effectively
00:11:34 --> 00:11:37 zero G, you are weightless. You're actually,
00:11:37 --> 00:11:39 you are experiencing the Earth's gravity, but
00:11:39 --> 00:11:40 so is the space station around you. When
00:11:40 --> 00:11:42 you're falling together, just like mentioned
00:11:42 --> 00:11:44 with the International Space Station
00:11:45 --> 00:11:48 at, uh, that point, if you had some way of
00:11:49 --> 00:11:51 sitting stationary in space, so in other
00:11:51 --> 00:11:54 words, you were not orbiting the Earth, you
00:11:54 --> 00:11:56 were motionless, but you had a rocket holding
00:11:56 --> 00:11:58 you up. You would still feel the Earth's
00:11:58 --> 00:12:00 gravity pulling you down because the rocket
00:12:00 --> 00:12:02 would be pushing up against your feet
00:12:02 --> 00:12:04 essentially, and you'd feel the strength of
00:12:04 --> 00:12:06 gravity there. You're, uh, at
00:12:06 --> 00:12:09 36 kilometers, which means you're 42
00:12:09 --> 00:12:11 kilometers from the center of the earth,
00:12:11 --> 00:12:13 which means you're seven times further from
00:12:13 --> 00:12:15 the middle of the Earth, uh, than we are
00:12:15 --> 00:12:17 here. The strength of gravity falls off as 1
00:12:17 --> 00:12:20 over distance squared. So you'd feel about 1
00:12:20 --> 00:12:23 50th of a G there. So if
00:12:23 --> 00:12:25 you were able to sit still rather than
00:12:25 --> 00:12:26 falling with the Space station, you would
00:12:26 --> 00:12:28 feel a little bit of gravity there, but it
00:12:28 --> 00:12:31 wouldn't be that intense at the lower
00:12:31 --> 00:12:34 altitudes. The effect
00:12:34 --> 00:12:36 is dominated not by your rotation movement,
00:12:36 --> 00:12:38 because you're going much slower than orbital
00:12:38 --> 00:12:41 speed, but by the fact that gravity is
00:12:41 --> 00:12:43 pulling you down, but the
00:12:43 --> 00:12:45 lift is being winched upwards.
00:12:46 --> 00:12:49 So if you lifted your space elevator up and
00:12:49 --> 00:12:52 you stopped at one of these stops, and that's
00:12:52 --> 00:12:54 why they talk about the stops, I suspect if
00:12:54 --> 00:12:57 you stopped at 300 km at a station just above
00:12:57 --> 00:12:59 the atmosphere, attached to the tether,
00:12:59 --> 00:13:02 moving around at the same speed the Earth's
00:13:02 --> 00:13:05 rotating underneath you, you'd feel an
00:13:05 --> 00:13:07 acceleration due to gravity that is a little
00:13:07 --> 00:13:08 bit smaller than that we feel at the surface
00:13:08 --> 00:13:11 of the Earth. Now, if you're at the top of
00:13:11 --> 00:13:13 Mount Everest, technically you feel a
00:13:13 --> 00:13:14 slightly lower acceleration due to gravity
00:13:14 --> 00:13:17 than you do at the sea level because
00:13:17 --> 00:13:19 you're further from the center of the Earth.
00:13:19 --> 00:13:22 So that one over R squared component in
00:13:22 --> 00:13:25 the acceleration due to gravity equation is
00:13:25 --> 00:13:27 a slightly bigger number on the R squared,
00:13:27 --> 00:13:29 which means your acceleration due to gravity
00:13:29 --> 00:13:31 is a slightly smaller number. But that's
00:13:31 --> 00:13:33 imperceptible to humans. But we can measure
00:13:33 --> 00:13:35 it with instrumentation. That, incidentally,
00:13:35 --> 00:13:38 is why, if you really wanted to, to,
00:13:38 --> 00:13:41 um, lose weight, um, but
00:13:41 --> 00:13:43 you're being lazy. If you want to get weighed
00:13:43 --> 00:13:45 in the place where you will wear the least on
00:13:45 --> 00:13:47 the Earth, you go to the top of that mountain
00:13:47 --> 00:13:49 near the equator. Is it anaconda? I think it
00:13:49 --> 00:13:52 is. Which is a point on the Earth that is
00:13:52 --> 00:13:54 furthest from the Earth's core. Because
00:13:54 --> 00:13:55 you've got the bulge of the Earth's equator
00:13:55 --> 00:13:58 on top of the height of the mountain.
00:13:59 --> 00:14:00 And you will feel a slightly smaller
00:14:00 --> 00:14:02 acceleration due to gravity there because
00:14:02 --> 00:14:04 you're further from the Earth's core. So at
00:14:04 --> 00:14:07 300km up, you've only changed your distance
00:14:07 --> 00:14:10 from the center of the earth by about 5%. And
00:14:10 --> 00:14:11 so you've probably changed the acceleration
00:14:11 --> 00:14:13 due to gravity by less than 10%. It's
00:14:13 --> 00:14:15 probably enough that you'd be able to notice
00:14:15 --> 00:14:17 it. Walking around would feel slightly
00:14:17 --> 00:14:20 unusual, but it wouldn't be a problem. The
00:14:20 --> 00:14:22 station number five that is mentioned here,
00:14:22 --> 00:14:25 at 6200km, that means
00:14:25 --> 00:14:27 you're nearly twice as far away from the
00:14:27 --> 00:14:29 center of the Earth now as we are on the
00:14:29 --> 00:14:30 surface of the Earth. Surface of the Earth,
00:14:30 --> 00:14:33 we're about 6 kilometers from the middle.
00:14:34 --> 00:14:35 Varies a little depending on your altitude
00:14:35 --> 00:14:37 above sea level and where you are on the
00:14:37 --> 00:14:39 globe. Yeah. Add another 6200
00:14:39 --> 00:14:42 km, you've effectively doubled the distance,
00:14:42 --> 00:14:45 which means 1 upon r squared is 1 over 2
00:14:45 --> 00:14:48 times 1 over 2 is 1 over 4. So the
00:14:48 --> 00:14:50 acceleration is a quarter of a g. So we've
00:14:50 --> 00:14:52 dropped the strength of gravitude field by a
00:14:52 --> 00:14:54 factor of four. And at that point that is
00:14:54 --> 00:14:57 hugely noticeable. It's a little bit stronger
00:14:57 --> 00:14:59 gravity than you'd have on the moon, but not
00:14:59 --> 00:15:02 by much. Now, I guess this is the kind of
00:15:02 --> 00:15:03 thing where you could, if you were sending
00:15:03 --> 00:15:06 people to Mars and you wanted them to
00:15:06 --> 00:15:09 experience Martian gravity and see if they
00:15:09 --> 00:15:11 could cope with it, you know, you had a
00:15:11 --> 00:15:13 training and a testing program and anybody
00:15:13 --> 00:15:15 that got too travel sick or whatever and
00:15:15 --> 00:15:17 couldn't adapt was bumped out of the program.
00:15:17 --> 00:15:19 What you do is you take this space elevator,
00:15:20 --> 00:15:22 you figure out exactly at what height above
00:15:22 --> 00:15:24 the ground, you would emulate Martian gravity
00:15:24 --> 00:15:26 perfectly and you build a training station
00:15:26 --> 00:15:28 there. Because at the end of the day, if
00:15:28 --> 00:15:29 you've got a space elevator, you know, you
00:15:29 --> 00:15:32 may as well put an extra level on it. Um, and
00:15:32 --> 00:15:34 that way you can train people up for Mars.
00:15:34 --> 00:15:35 And I could almost imagine a future where
00:15:35 --> 00:15:37 they have one for the moon as well. You know,
00:15:37 --> 00:15:39 go up there, spend a few weeks training in
00:15:39 --> 00:15:41 lunar gravity and see if you can hack it on
00:15:41 --> 00:15:43 the surface of the M moon. And anybody who
00:15:43 --> 00:15:45 can't, no shame. We all have slightly
00:15:45 --> 00:15:47 different balance systems and all the rest of
00:15:47 --> 00:15:50 it, if you can't adjust, that's fine, you can
00:15:50 --> 00:15:52 work on Earth, no problem. But so it
00:15:52 --> 00:15:55 does sound like the science in this
00:15:55 --> 00:15:58 book is robust. In other words, it's hard,
00:15:58 --> 00:15:59 hard sci fi.
00:15:59 --> 00:16:01 It's based on our current understanding of
00:16:01 --> 00:16:03 physics and that's how it would work on space
00:16:03 --> 00:16:05 elevator. So hopefully that makes sense. And
00:16:05 --> 00:16:08 it is a really good example of how you can
00:16:08 --> 00:16:10 use a science fiction book to t to teach
00:16:10 --> 00:16:11 people science fact.
00:16:12 --> 00:16:14 Andrew Dunkley: Yeah, absolutely. Yeah. Thanks, Barry. Um,
00:16:14 --> 00:16:17 just a side question, Jonti. Do you think
00:16:17 --> 00:16:19 we ever will build such a thing?
00:16:21 --> 00:16:23 Jonti Horner: I'd be a fool to say no on it. I really hope
00:16:23 --> 00:16:26 that we do. And um, given the impact we've
00:16:26 --> 00:16:29 seen both good and bad, from the
00:16:29 --> 00:16:31 advent of reusable spacecraft and the growth
00:16:31 --> 00:16:33 of commercial space, that's dropped the cost
00:16:33 --> 00:16:36 of launching kilogram of material to space by
00:16:36 --> 00:16:38 between a factor of 10 and factor of 100. And
00:16:38 --> 00:16:40 it's been revolutionary. If you could drop
00:16:40 --> 00:16:43 that cost to essentially nothing. What
00:16:43 --> 00:16:46 that enables is an enormous expansion in
00:16:46 --> 00:16:49 our use of space. It also enables the kind of
00:16:49 --> 00:16:51 space tourism type stuff because if you
00:16:52 --> 00:16:54 have a docking station at geostationary
00:16:54 --> 00:16:57 orbit, you've Already done a hell of a lot of
00:16:57 --> 00:16:59 the work of getting out of Earth's gravity.
00:17:00 --> 00:17:02 So it's much easier to launch to Mars or the
00:17:02 --> 00:17:05 moon or pick your tourist destination from
00:17:05 --> 00:17:08 there. Pick your research destination, you
00:17:08 --> 00:17:10 hugely reduce the cost of doing
00:17:10 --> 00:17:13 both. Research, commerce, tourism.
00:17:13 --> 00:17:15 By getting people up to that altitude. You
00:17:15 --> 00:17:17 don't have to get through the atmosphere, but
00:17:17 --> 00:17:19 you also don't have to burn your rocket to
00:17:19 --> 00:17:21 get up, uh, through that hardest, steepest
00:17:21 --> 00:17:24 part of Earth's gravity well. So once it is
00:17:24 --> 00:17:27 technologically feasible, I suspect what
00:17:27 --> 00:17:28 you'll have is it'll become technologically
00:17:28 --> 00:17:31 feasible. Then not too long after that, it
00:17:31 --> 00:17:33 will become commercially feasible. And that's
00:17:33 --> 00:17:35 the point people look at doing it. And, uh,
00:17:35 --> 00:17:37 the big caveat there would be, is it actually
00:17:37 --> 00:17:40 ever going to be technologically feasible?
00:17:40 --> 00:17:42 But it's near enough future science that
00:17:42 --> 00:17:44 people have already had suggestions about the
00:17:44 --> 00:17:47 kind of materials you could use to make
00:17:47 --> 00:17:50 the cable. Because that's a big
00:17:50 --> 00:17:53 constraint is actually making the cable, um,
00:17:53 --> 00:17:55 would need to be a lot stronger than spider
00:17:55 --> 00:17:57 silk, for example. But it is
00:17:58 --> 00:18:01 not so far beyond what we can make now that
00:18:01 --> 00:18:03 people think it's impossible. Rather, people
00:18:03 --> 00:18:05 think it could be feasible, but we don't know
00:18:05 --> 00:18:07 how yet. And in that kind of context, we're
00:18:07 --> 00:18:09 incredibly good at doing the impossible and
00:18:09 --> 00:18:12 the improbable as a species. So, uh, so long
00:18:12 --> 00:18:15 as we don't wipe each other out, so long as
00:18:15 --> 00:18:18 the shutdown eventually ends, then perhaps
00:18:18 --> 00:18:20 we'll be able to figure this out. And, you
00:18:20 --> 00:18:23 know, probably not in our lifetime, but may
00:18:23 --> 00:18:24 well not be as far beyond that as you'd
00:18:24 --> 00:18:25 think.
00:18:25 --> 00:18:27 Andrew Dunkley: Well, uh, if you go back 200 years and tell
00:18:27 --> 00:18:29 people, hey, I, you know, where I come from,
00:18:29 --> 00:18:31 we've been to the moon, they'd think you were
00:18:31 --> 00:18:34 a witch. They just wouldn't believe
00:18:34 --> 00:18:37 it. So, uh, who knows what's possible in 200
00:18:37 --> 00:18:37 years time?
00:18:37 --> 00:18:39 Jonti Horner: Yeah, the thing that makes my head hurt with
00:18:39 --> 00:18:41 that, uh, is we're almost at the point. In
00:18:41 --> 00:18:43 fact, I think we possibly are at the point
00:18:43 --> 00:18:45 now where it is longer since the first
00:18:45 --> 00:18:48 moonwalk than that moonwalk was from the
00:18:48 --> 00:18:49 first powered flight.
00:18:49 --> 00:18:51 Andrew Dunkley: I know. Isn't it amazing?
00:18:52 --> 00:18:54 It's incredible how far we've come in such a
00:18:54 --> 00:18:57 short period of time. M thank you, Barry. Um,
00:18:57 --> 00:18:58 great question.
00:18:58 --> 00:19:00 Uh, our next question coming up in a moment
00:19:00 --> 00:19:02 on Space Nuts.
00:19:06 --> 00:19:09 Space Nuts. And you're with Andrew Dunkley
00:19:09 --> 00:19:11 and John T. Horner. Um, this one comes from
00:19:11 --> 00:19:14 Casey in Colorado. I was hoping that you
00:19:14 --> 00:19:16 could Please explain why TOI
00:19:17 --> 00:19:20 6894B is such a big deal
00:19:20 --> 00:19:23 and what it means for our understanding of
00:19:23 --> 00:19:24 the universe. Love the show, and I hope
00:19:24 --> 00:19:25 you're both well.
00:19:25 --> 00:19:26 Jonti Horner: Thanks.
00:19:26 --> 00:19:28 Andrew Dunkley: Thank you, Casey. Yeah. So I did a bit of
00:19:28 --> 00:19:30 research on this, uh, particular planet,
00:19:30 --> 00:19:33 TOI 6894. It's a massive,
00:19:34 --> 00:19:36 massive gas giant planet. But what makes it
00:19:36 --> 00:19:39 unusual is that its star
00:19:39 --> 00:19:41 is, um, a bit of a mouse.
00:19:42 --> 00:19:45 So they're trying to figure out how such a
00:19:45 --> 00:19:46 massive planet can exist
00:19:47 --> 00:19:50 next to such a tiny star. I think that's the
00:19:50 --> 00:19:51 guts of it, isn't it?
00:19:51 --> 00:19:54 Jonti Horner: It is. And it's a really good example, again,
00:19:54 --> 00:19:57 of the detective story side of
00:19:57 --> 00:20:00 astronomy, the way that we can't really
00:20:00 --> 00:20:01 do experiments, so we have to learn through
00:20:01 --> 00:20:03 observation. And so the interplay is not
00:20:03 --> 00:20:05 experiment and theory like it is in other
00:20:05 --> 00:20:07 disciplines, but it's observation and the.
00:20:07 --> 00:20:09 And, um, that leads to our science being
00:20:09 --> 00:20:11 different in subtle ways, even down to the
00:20:11 --> 00:20:13 structure of how we write and how we
00:20:13 --> 00:20:15 communicate. It's less about testing
00:20:15 --> 00:20:16 hypotheses than other disciplines. You know,
00:20:16 --> 00:20:19 there's a lot of complexity in that. Now,
00:20:19 --> 00:20:21 if you go back to when I was a kid and I was
00:20:22 --> 00:20:23 learning all about astronomy, we didn't know
00:20:23 --> 00:20:26 of any planet from any other star. And we
00:20:26 --> 00:20:27 thought we had a very good feeling of how the
00:20:27 --> 00:20:29 solar system formed and therefore, by
00:20:29 --> 00:20:31 extension, what kind of planets we would
00:20:31 --> 00:20:33 find. Yeah, and we expected that you'd find
00:20:33 --> 00:20:36 giant planets like Jupiter out beyond the
00:20:36 --> 00:20:38 snow line, you know, several astronomical
00:20:38 --> 00:20:39 units from their star, going around on orbits
00:20:39 --> 00:20:41 that are measured in decades, and rocky
00:20:41 --> 00:20:43 planets in the interior. And that's how
00:20:43 --> 00:20:44 planetary systems would form and the solar
00:20:44 --> 00:20:47 system would be typical. We then found
00:20:47 --> 00:20:50 51 Pegasi B, which is a planet comparable to
00:20:50 --> 00:20:52 Jupiter, going around its star every four
00:20:52 --> 00:20:55 days. And that kind of threw everything out.
00:20:55 --> 00:20:57 And we had to improve our theories. Now what
00:20:57 --> 00:21:00 it led to was a refinement of the theories of
00:21:00 --> 00:21:02 planets forming in disks rather than them
00:21:02 --> 00:21:04 being totally chucked out on something new.
00:21:04 --> 00:21:06 But that first discovery of a planet around a
00:21:06 --> 00:21:08 sun like star really set the scene for the
00:21:08 --> 00:21:11 fact that the diversity of planets we find
00:21:11 --> 00:21:14 around other stars is overwhelmingly
00:21:14 --> 00:21:16 greater than we could have ever imagined.
00:21:16 --> 00:21:18 Planets are ubiquitous. Every star has them.
00:21:18 --> 00:21:20 That's what we've learned. But the variety of
00:21:20 --> 00:21:22 planets is much greater than we could have
00:21:22 --> 00:21:25 imagined. And all of that data has been
00:21:25 --> 00:21:27 a fabulous resource for scientists trying to
00:21:27 --> 00:21:29 understand the process of planet formation
00:21:29 --> 00:21:32 and the variety of ways that that process can
00:21:32 --> 00:21:35 proceed effectively. Every planetary system
00:21:35 --> 00:21:37 will be unique in the same way every human's
00:21:37 --> 00:21:39 unique. You know, they're the product of the
00:21:39 --> 00:21:41 environment that they form in. The mass of
00:21:41 --> 00:21:43 the disk is important, the mass of the star,
00:21:43 --> 00:21:44 but also the cluster environment they form
00:21:44 --> 00:21:47 in. There's a lot of things going on that
00:21:47 --> 00:21:49 mean if you have two identical stars with two
00:21:49 --> 00:21:51 identical disks, you'll still get different
00:21:51 --> 00:21:53 planetary systems at the end. So we're
00:21:53 --> 00:21:55 learning more about planet formation. And
00:21:55 --> 00:21:58 it's the outliers and the oddities that
00:21:58 --> 00:21:59 really drive that science forward.
00:22:00 --> 00:22:03 Which brings us to TOI 6894. What we
00:22:03 --> 00:22:05 found typically is that, uh, giant planets
00:22:05 --> 00:22:08 are common in the cosmos. We find them easier
00:22:08 --> 00:22:09 than everything else because they're more
00:22:09 --> 00:22:12 obvious. So our discovery techniques are
00:22:12 --> 00:22:14 biased towards finding planets the size of
00:22:14 --> 00:22:16 Jupiter and Saturn and against finding
00:22:16 --> 00:22:18 planets the size of the Earth. That's why we
00:22:18 --> 00:22:20 find a lot more of them. And, um, what the
00:22:20 --> 00:22:22 results have shown is that, uh, giant
00:22:22 --> 00:22:24 planets, massive planets like Jupiter and
00:22:24 --> 00:22:27 Saturn, are, um, more common the more massive
00:22:27 --> 00:22:30 the star is. They're also more common the
00:22:30 --> 00:22:32 higher the metallicity of the star is. So the
00:22:32 --> 00:22:33 higher the amount of solid material would
00:22:33 --> 00:22:36 have been around that star. And typically
00:22:36 --> 00:22:39 we don't find giant planets like Jupiter
00:22:39 --> 00:22:42 and Saturn around the lowest mass stars.
00:22:42 --> 00:22:44 And the argument has always been that low
00:22:44 --> 00:22:46 mass stars form from low mass disks where
00:22:46 --> 00:22:48 there's just not simply enough for planets to
00:22:48 --> 00:22:51 form there. Then you get
00:22:51 --> 00:22:54 TOI 6894B. So the
00:22:54 --> 00:22:57 star TOI 6894 is a little red dwarf.
00:22:57 --> 00:22:59 It's only about 20% the mass of the sun,
00:22:59 --> 00:23:02 about 238 light years away. The
00:23:02 --> 00:23:05 planet going round it is a little bit bigger
00:23:05 --> 00:23:07 than Saturn, but about half the mass of our
00:23:07 --> 00:23:09 giant planet. So it's another one of these
00:23:09 --> 00:23:11 superpuff planets that we've talked about
00:23:11 --> 00:23:13 before. It's heavily irradiated, has been
00:23:13 --> 00:23:15 inflated, and that probably suggests that
00:23:15 --> 00:23:18 it's migrated in in the recent past. Now
00:23:18 --> 00:23:20 people who've looked at data from Kepler
00:23:21 --> 00:23:23 and TESS more recently, which looked at so
00:23:23 --> 00:23:25 many stars, have been able to do a kind of
00:23:25 --> 00:23:28 statistical study. And what they've found is,
00:23:28 --> 00:23:30 uh, for red dwarfs like TOI,
00:23:31 --> 00:23:33 um, 6894, only about
00:23:33 --> 00:23:36 1.5% of all red dwarfs harbor any giant
00:23:36 --> 00:23:38 planets. And TOI
00:23:38 --> 00:23:41 6894 is the least massive star to be found
00:23:41 --> 00:23:44 with an orbiting giant planet around it. So
00:23:44 --> 00:23:46 that's why it's really, really interesting.
00:23:46 --> 00:23:48 Now there's a number of different processes
00:23:48 --> 00:23:51 that go on in planet formation and, um, star
00:23:51 --> 00:23:53 formation. And we've talked before about the
00:23:53 --> 00:23:56 Blurred lines between planets and
00:23:56 --> 00:23:58 brown dwarfs and stars. And back in the day,
00:23:58 --> 00:24:00 we thought we had a very clear rational
00:24:00 --> 00:24:01 explanation that they're formed in different
00:24:01 --> 00:24:04 ways. But now we see brown
00:24:04 --> 00:24:06 dwarfs being discovered free floating that
00:24:06 --> 00:24:09 are lower mass than the canonical traditional
00:24:09 --> 00:24:11 13 Jupiter mass limit. Anything smaller than
00:24:11 --> 00:24:13 13 Jupiter mass used to be thought of as a
00:24:13 --> 00:24:15 planet. Similarly, we're finding things that
00:24:15 --> 00:24:16 they're calling planets that are more than 13
00:24:16 --> 00:24:18 Jupiter masses. So the lines are getting
00:24:18 --> 00:24:18 blurred.
00:24:19 --> 00:24:19 Andrew Dunkley: Yeah.
00:24:19 --> 00:24:22 Jonti Horner: And I think we may see a bit of a
00:24:22 --> 00:24:24 paradigm shift in years and decades to come,
00:24:25 --> 00:24:27 where part of what defines whether you're a
00:24:27 --> 00:24:29 planet or a brown dwarf at the top end is
00:24:29 --> 00:24:31 actually how you formed and by extension,
00:24:31 --> 00:24:34 what's buried deep in your core. So a
00:24:34 --> 00:24:36 planet like Jupiter has a massive,
00:24:37 --> 00:24:40 you know, 20, 30 earth mass, solid core at
00:24:40 --> 00:24:41 the middle because it formed from a process
00:24:41 --> 00:24:44 of core accretion. You get solid material
00:24:44 --> 00:24:46 agglomerating, forming bigger and bigger
00:24:46 --> 00:24:47 bits, until you form things kilometers
00:24:47 --> 00:24:50 across, then thousands of kilometers across
00:24:50 --> 00:24:52 objects like the Earth. And the more they
00:24:52 --> 00:24:54 eat, the bigger they get. Eventually you get
00:24:54 --> 00:24:56 to 20 or 30 times the mass of the earth,
00:24:56 --> 00:24:58 well, 10 or 12 times the mass of the Earth to
00:24:58 --> 00:25:00 start the process. When you're at that point,
00:25:00 --> 00:25:02 your gravity is strong enough to start
00:25:02 --> 00:25:04 capturing hydrogen and helium gas from the
00:25:04 --> 00:25:06 nebula that previously would have escaped,
00:25:06 --> 00:25:08 you finally can hold onto, um, it. And, um,
00:25:08 --> 00:25:10 because there's more of hydrogen and helium
00:25:10 --> 00:25:12 than everything else combined by a couple of
00:25:12 --> 00:25:15 orders of magnitude, 98% of everything is
00:25:15 --> 00:25:17 hydrogen or helium. Suddenly you've got this
00:25:17 --> 00:25:19 enormous new untapped food source. You can
00:25:19 --> 00:25:21 quickly devour all there is, and your mass
00:25:21 --> 00:25:23 grows really rapidly until you open a gap in
00:25:23 --> 00:25:25 the disk, and voila, you've got a giant
00:25:25 --> 00:25:27 planet in a gap. And we talked about this a
00:25:27 --> 00:25:30 bit last week. That's core accretion.
00:25:30 --> 00:25:32 That leads to giant planets that are planets
00:25:32 --> 00:25:34 with a solid core and a thick atmosphere. And
00:25:34 --> 00:25:36 that atmosphere can be the bulk of their
00:25:36 --> 00:25:38 mass. You've then got a
00:25:38 --> 00:25:40 method called gravitational instability,
00:25:40 --> 00:25:42 where your disk is sufficiently massive
00:25:42 --> 00:25:44 compared to the star in the middle, that it
00:25:44 --> 00:25:47 can become unstable itself. And you can get
00:25:47 --> 00:25:49 it essentially globbing together to form
00:25:49 --> 00:25:51 massive objects on a very short time scale.
00:25:51 --> 00:25:53 And that's probably, to be honest, the
00:25:53 --> 00:25:56 process by which binary stars form, where you
00:25:56 --> 00:25:58 get a second star forming on a quite wide,
00:25:58 --> 00:26:00 elongated orbit, whatever. And I've always
00:26:00 --> 00:26:03 had a suspicion back from when earlier in my
00:26:03 --> 00:26:05 career I was at the University of Bern, and
00:26:05 --> 00:26:07 this is 20 years ago now, there was this kind
00:26:07 --> 00:26:09 of conflict for giant Planets where people
00:26:09 --> 00:26:12 said one of these two methods will be right
00:26:12 --> 00:26:13 and the other one will be wrong. And you've
00:26:13 --> 00:26:15 got core accretion or, uh, gravitational
00:26:15 --> 00:26:16 instability. And it was a big kind of which
00:26:16 --> 00:26:18 one of them is right. And I've always had the
00:26:18 --> 00:26:20 feeling that in the right conditions both of
00:26:20 --> 00:26:23 them can happen. And this suspicion that
00:26:23 --> 00:26:26 brown dwarfs and stellar companions
00:26:26 --> 00:26:28 probably form through this gravitational
00:26:28 --> 00:26:31 instability process, which leads to more
00:26:31 --> 00:26:32 instability and kind of lowers the likelihood
00:26:32 --> 00:26:34 of planets then forming in the system. And
00:26:34 --> 00:26:36 you'd form an object there, ah, that doesn't
00:26:36 --> 00:26:38 have that massive core in the center. It's
00:26:38 --> 00:26:41 basically the composition will match the
00:26:41 --> 00:26:43 composition of the material in the universe.
00:26:44 --> 00:26:46 This is a really interesting one because this
00:26:46 --> 00:26:48 planet is so much so massive compared to
00:26:48 --> 00:26:51 its star. This is kind of equivalent to the
00:26:51 --> 00:26:54 sun having a 5 or 10 Jupiter mass planet,
00:26:54 --> 00:26:56 probably something like that, because m more
00:26:56 --> 00:26:57 massive star would have more mass and you
00:26:57 --> 00:26:59 wouldn't just five times the mass of the star
00:26:59 --> 00:27:01 is five times the mass of the planet. It will
00:27:01 --> 00:27:03 go a bit more than that. So it's a real
00:27:03 --> 00:27:06 surprise and there's a lot of investigation
00:27:06 --> 00:27:07 to be done to try and figure out what the
00:27:07 --> 00:27:10 formation process of this object is. The fact
00:27:10 --> 00:27:13 it's a super puff, it's puffed up, it's
00:27:13 --> 00:27:14 bigger than Saturn, but less massive than
00:27:14 --> 00:27:17 Saturn, suggests that, um, either
00:27:17 --> 00:27:19 it's very close into the star and it's
00:27:19 --> 00:27:22 getting hugely irradiated. If that's the
00:27:22 --> 00:27:23 case and it's been losing mass, it was
00:27:23 --> 00:27:26 probably more massive in the past. Um, which
00:27:26 --> 00:27:28 adds further weight to maybe this was a
00:27:28 --> 00:27:30 bigger thing in the past and maybe it could
00:27:30 --> 00:27:32 have been a very low mass brown dwarf rather
00:27:32 --> 00:27:34 than a very high mass planet. Or maybe it's
00:27:34 --> 00:27:37 telling us that you can get M dwarfs, red
00:27:37 --> 00:27:39 dwarfs, which have a disk massive enough to
00:27:39 --> 00:27:41 form giant planets on occasion in the right
00:27:41 --> 00:27:44 setup, and we just need to learn more.
00:27:45 --> 00:27:47 Um, but it seems very unlikely
00:27:48 --> 00:27:51 that if the properties of the disk
00:27:51 --> 00:27:53 around this star, uh, were similar to the
00:27:53 --> 00:27:55 bulk of disk we found, there should not have
00:27:55 --> 00:27:58 been enough solid material to get the core
00:27:58 --> 00:28:00 accretion process to go quickly enough for
00:28:00 --> 00:28:02 you to get a giant planet, never mind one
00:28:02 --> 00:28:04 close enough in like this one, to then become
00:28:04 --> 00:28:07 a bit of a superpuff. So there's a lot to
00:28:07 --> 00:28:08 learn. It's very close to its star. It's only
00:28:09 --> 00:28:12 3.9 million kilometers out from the
00:28:12 --> 00:28:14 star. So it's much more
00:28:14 --> 00:28:17 comparable to the Jovian moons. If you
00:28:17 --> 00:28:19 imagine the star being where Jupiter is, this
00:28:19 --> 00:28:20 is comparable to some of the moons of Jupiter
00:28:20 --> 00:28:23 and distance. And that's another of the
00:28:23 --> 00:28:24 reasons it's just really hard to imagine how
00:28:24 --> 00:28:26 it could been have form so close in.
00:28:27 --> 00:28:29 There's a lot to dig into in this. They're
00:28:29 --> 00:28:30 looking at the chemistry of the atmosphere
00:28:30 --> 00:28:32 because this planet's close enough in to be
00:28:32 --> 00:28:34 hot enough that we can actually get light
00:28:34 --> 00:28:36 from it and we can look at its atmosphere
00:28:36 --> 00:28:38 seems to be kind of methane dominated, I
00:28:38 --> 00:28:40 think, which is really, really odd. Um,
00:28:40 --> 00:28:42 there's all sorts of weird stuff going on.
00:28:43 --> 00:28:46 Um, but because red dwarf
00:28:46 --> 00:28:47 stars are so common, even though giant
00:28:47 --> 00:28:50 planets like this are rare per red dwarf,
00:28:50 --> 00:28:52 there's probably a hell of a lot of them out
00:28:52 --> 00:28:53 there. You know, red dwarfs are the most
00:28:53 --> 00:28:56 common star in the galaxy by far. You know,
00:28:56 --> 00:28:58 some estimates are, you know, up to three
00:28:58 --> 00:29:01 quarters of all gas in our size in our galaxy
00:29:01 --> 00:29:02 will count as red dwarfs. Which means he
00:29:02 --> 00:29:05 could have 100, 200,
00:29:05 --> 00:29:08 300 billion of them out there. So even if
00:29:08 --> 00:29:11 only 1% of those stars have a giant planet
00:29:11 --> 00:29:13 like this, you know, 1% of,
00:29:14 --> 00:29:16 you know, 100 billion stars is still a
00:29:16 --> 00:29:17 billion stars.
00:29:17 --> 00:29:18 Jonti Horner: Yes.
00:29:18 --> 00:29:20 Jonti Horner: Now maybe this planet is both rare and common
00:29:20 --> 00:29:21 at the same time.
00:29:21 --> 00:29:24 Andrew Dunkley: Yeah, that sounds like a very good
00:29:24 --> 00:29:27 theory actually. Um, Casey, thanks
00:29:27 --> 00:29:29 for the question. If you'd like to read up on
00:29:29 --> 00:29:32 it, uh, you can go to uh, Psy News,
00:29:32 --> 00:29:34 the website, because they've got a great
00:29:34 --> 00:29:35 article on it, uh, but they've also published
00:29:35 --> 00:29:38 a recent paper, uh, in the
00:29:38 --> 00:29:40 journal Nature Astronomy.
00:29:43 --> 00:29:45 Jonti Horner: 3, 2, 1.
00:29:46 --> 00:29:46 Space.
00:29:48 --> 00:29:49 Andrew Dunkley: Our uh, final question.
00:29:50 --> 00:29:52 Jonti. Uh, I don't know how to introduce
00:29:52 --> 00:29:55 this, so I'm just going to let it speak for
00:29:55 --> 00:29:55 itself.
00:29:55 --> 00:29:57 Jonti Horner: Hello, space nuts.
00:29:57 --> 00:29:59 Andrew Dunkley: This is Philip McCrackpipe, future Nobel
00:29:59 --> 00:30:02 Prize winner, here again. This time I've got
00:30:02 --> 00:30:03 my bony lassie.
00:30:03 --> 00:30:06 Jonti Horner: The famous English soprano. I need a fix here
00:30:06 --> 00:30:06 with me.
00:30:07 --> 00:30:10 Jonti Horner: That's a neater fix. F I C K S.
00:30:10 --> 00:30:13 Thank you. Not if F I X.
00:30:13 --> 00:30:16 So many people get that wrong. I have this
00:30:16 --> 00:30:19 question about Gale Crater on Mars and what
00:30:19 --> 00:30:21 kind of life it might have supported. Being
00:30:21 --> 00:30:24 a famous soprano, I'd like uh, to sing it
00:30:24 --> 00:30:27 to you. Pardon my voice today
00:30:27 --> 00:30:30 I have a slight touch of the anthrax.
00:30:32 --> 00:30:35 How many lovely life old might have grown
00:30:35 --> 00:30:37 in an ancient Martian crater?
00:30:38 --> 00:30:41 Could they have thrived or only just survived
00:30:41 --> 00:30:43 in an ancient Martian?
00:30:45 --> 00:30:47 Were they all just single soul? Did they fly
00:30:47 --> 00:30:49 like Tinkerbell and laugh and sing and play
00:30:50 --> 00:30:52 a microscopic trees?
00:30:53 --> 00:30:56 How, um, many lovely life forms made grown in
00:30:56 --> 00:30:59 an ancient Martian crater?
00:30:59 --> 00:30:59 Jonti Horner: Ah.
00:30:59 --> 00:31:02 Jonti Horner: Did they breathe the atmosphere where the
00:31:02 --> 00:31:04 predators, the fear elucidate your views,
00:31:04 --> 00:31:08 ecosystem.
00:31:10 --> 00:31:12 Thank lovely space nuts for listening to this
00:31:12 --> 00:31:15 tripe about an ancient Martian
00:31:15 --> 00:31:16 creator.
00:31:22 --> 00:31:25 Andrew Dunkley: Uh, um, I hope you get over the antlex real
00:31:25 --> 00:31:28 soon. Thanks, Anita. Um, I
00:31:28 --> 00:31:29 think I need a very.
00:31:29 --> 00:31:31 Jonti Horner: Different kind of musical ensemble. If I
00:31:31 --> 00:31:32 remember rightly.
00:31:32 --> 00:31:34 Andrew Dunkley: Yes, I think I need a fix.
00:31:34 --> 00:31:34 Jonti Horner: Uh.
00:31:36 --> 00:31:39 Andrew Dunkley: Bottom line, was there, or
00:31:39 --> 00:31:42 could there still be life in Gale Crater and
00:31:42 --> 00:31:42 what would it be like?
00:31:43 --> 00:31:46 Jonti Horner: Lots of places to go with this. I mean, two
00:31:46 --> 00:31:48 immediate diversions just spring to mind
00:31:48 --> 00:31:49 listening to that. It's lovely to get a
00:31:49 --> 00:31:51 musical entry from such a storied soprano,
00:31:51 --> 00:31:54 but reminds me, probably my favorite group,
00:31:55 --> 00:31:57 Finnish symphonic metal group called
00:31:57 --> 00:32:00 Nightwish. And this is relevant, I promise.
00:32:00 --> 00:32:03 Um, symphonic metal is this weird fusion of
00:32:03 --> 00:32:05 metal and opera, so you could describe it as
00:32:05 --> 00:32:08 operatic met. And the lead singer is a very
00:32:08 --> 00:32:11 storied classical soprano called Flo
00:32:11 --> 00:32:13 Jansen, who's just ridiculously awesome in
00:32:13 --> 00:32:16 many, many ways. Um, reason it's relevant is
00:32:16 --> 00:32:17 we were talking earlier on about Eugene
00:32:17 --> 00:32:20 Shoemaker, um, in the previous episode about
00:32:20 --> 00:32:22 Asher's going to the moon, things like this.
00:32:23 --> 00:32:26 Um, Nightwish, on their most recent
00:32:26 --> 00:32:29 no album before last had a track called
00:32:29 --> 00:32:31 Shoemaker, which was a eulogy, a tribute to
00:32:31 --> 00:32:34 Eugene Shoemaker, which has a lot of rocky
00:32:34 --> 00:32:36 stuff at the start, but from about 3 minutes
00:32:36 --> 00:32:38 50 onwards has a very, very operatic,
00:32:39 --> 00:32:41 classical, um, Latin funeral mass,
00:32:42 --> 00:32:44 um, which is utterly astonishing. So I do
00:32:44 --> 00:32:46 recommend people. I don't know if we can play
00:32:46 --> 00:32:47 it on the podcast. I don't know if we can
00:32:47 --> 00:32:49 play out because I don't know how rights
00:32:49 --> 00:32:50 issues work.
00:32:50 --> 00:32:53 Andrew Dunkley: Um, but, yeah, there are rights issues
00:32:53 --> 00:32:56 which precludes us, I'm afraid. I did
00:32:56 --> 00:32:58 listen to what you sent me. You sent me a
00:32:58 --> 00:33:00 link, uh, on YouTube Music, so we could
00:33:00 --> 00:33:02 probably send people there.
00:33:02 --> 00:33:04 Jonti Horner: But, yeah, it's a bit of a musical tour de
00:33:04 --> 00:33:06 force because it's got bits from William
00:33:06 --> 00:33:09 Shakespeare in there, which is the epitaph on
00:33:09 --> 00:33:11 Schumacher's tomb. That's why you've got the
00:33:11 --> 00:33:13 bit of Shakespeare's book and what in that.
00:33:13 --> 00:33:15 It's unusual, but it's incredibly touching
00:33:16 --> 00:33:18 anyway, so. Love a bit of musical science.
00:33:18 --> 00:33:20 The other thing that occurs without casting
00:33:20 --> 00:33:23 any aspersions on Anita there is the ability
00:33:23 --> 00:33:25 to sing while saying in character, which is
00:33:25 --> 00:33:28 good. And it reminds me of another thing I
00:33:28 --> 00:33:30 listened to, and I've listened to multiple
00:33:30 --> 00:33:32 times now, the phenomenon that is Dungeon
00:33:32 --> 00:33:35 Crawler Carl. Um, and at the end of the
00:33:35 --> 00:33:38 first audiobook, I was a bit put
00:33:38 --> 00:33:40 aback because there wasn't a cast list. And I
00:33:40 --> 00:33:43 thought, hang on, this is a bit Dodged.
00:33:43 --> 00:33:45 There's multiple people involved with this
00:33:45 --> 00:33:46 who are not getting credit. There's just this
00:33:46 --> 00:33:48 one guy getting credit for doing all the
00:33:48 --> 00:33:49 voice work and all the rest of it. And it
00:33:49 --> 00:33:52 really is just one guy. And it's
00:33:52 --> 00:33:54 remarkable how certain
00:33:54 --> 00:33:57 performers can voice multiple different
00:33:57 --> 00:33:59 characters to a degree of distinction that
00:34:00 --> 00:34:02 um, you assume that there's multiple people
00:34:02 --> 00:34:04 involved in the voicing. So, you know,
00:34:04 --> 00:34:07 incredible ability to sing well in character
00:34:07 --> 00:34:09 and stuff like that. So huge uh, credit on
00:34:09 --> 00:34:12 that in terms of the question and
00:34:12 --> 00:34:13 questions.
00:34:13 --> 00:34:15 It's all about life on Mars. Now we know that
00:34:15 --> 00:34:18 Mars in its youth was both
00:34:18 --> 00:34:21 warm and wet. It was an ocean planet that's
00:34:21 --> 00:34:23 fairly well established. Uh, and the
00:34:23 --> 00:34:25 transition from warm, wet Mars to cool, dry
00:34:25 --> 00:34:27 Mars would have been very slow and gradual.
00:34:27 --> 00:34:30 So any life that did get going will have had
00:34:30 --> 00:34:32 time to adapt and move potentially. That's a
00:34:32 --> 00:34:34 big part of the focus of the search for life
00:34:34 --> 00:34:37 on Mars. Both looking for evidence of past
00:34:37 --> 00:34:39 life and um, that's part of what the rovers
00:34:39 --> 00:34:41 are doing, driving around in gray in Gale and
00:34:41 --> 00:34:44 Jezero Crater, or Jezero Crater I think it's
00:34:44 --> 00:34:46 pronounced. It's also why we're interested,
00:34:46 --> 00:34:48 for example in the lakes of permanent liquid
00:34:48 --> 00:34:51 water at Mars south pole. But we
00:34:51 --> 00:34:52 don't know for a fact that there was life on
00:34:52 --> 00:34:55 Mars. It still was there, wasn't there? We're
00:34:55 --> 00:34:58 trying to find out. The idea though is that
00:34:58 --> 00:35:01 when Mars was young it was warm and wet, it
00:35:01 --> 00:35:03 had oceans. There may have been icy, slushy
00:35:03 --> 00:35:05 oceans, more like what you get in the Arctic
00:35:05 --> 00:35:07 than what you get near the equator. We don't
00:35:07 --> 00:35:09 fully know on that yet. But there was a
00:35:09 --> 00:35:12 vast expanse of liquid water on Mars surface
00:35:12 --> 00:35:14 for an incredibly long protracted period.
00:35:15 --> 00:35:17 All the conditions that on Earth would lead
00:35:17 --> 00:35:20 to life establishing and thriving. So
00:35:20 --> 00:35:22 there's a very real possibility that Gale
00:35:22 --> 00:35:25 Krata, this ancient Martian creator, was
00:35:25 --> 00:35:28 teeming with life in the past. It is,
00:35:28 --> 00:35:31 I think. So the challenge here is that
00:35:31 --> 00:35:33 we've only got one example of life in the
00:35:33 --> 00:35:35 universe to go off, which is life on the
00:35:35 --> 00:35:37 Earth. So we tend to form all our
00:35:37 --> 00:35:39 assumptions about the pathway that life will
00:35:39 --> 00:35:41 follow and how it will develop based on that
00:35:41 --> 00:35:44 example. Now just with the last question, we
00:35:44 --> 00:35:47 were talking about our ideas on the formation
00:35:47 --> 00:35:49 of planets when we only had one planetary
00:35:49 --> 00:35:51 system to go on and how wrong they were when
00:35:51 --> 00:35:53 we found the second planetary system around a
00:35:53 --> 00:35:56 sun like star. So the caveat to everything
00:35:56 --> 00:35:58 I'm about to say is that currently we know of
00:35:58 --> 00:36:00 one place with life and one planet with life.
00:36:00 --> 00:36:03 So I'm basing it off assumptions based on how
00:36:03 --> 00:36:06 things developed on Earth. And on Earth, we
00:36:06 --> 00:36:08 had simple life from about three and a
00:36:08 --> 00:36:11 half thousand million years ago. The evidence
00:36:11 --> 00:36:13 of, so the oldest fossils on Earth that are
00:36:13 --> 00:36:16 widely accepted, it's about 3.5 billion years
00:36:16 --> 00:36:18 ago, found in the Pilbara region in Western
00:36:18 --> 00:36:20 Australia. There are some fossils that are
00:36:20 --> 00:36:21 arguably older, but they're still
00:36:21 --> 00:36:24 controversial. For
00:36:24 --> 00:36:27 the first 3 billion years of life on Earth,
00:36:27 --> 00:36:29 all you had was single celled life. You had
00:36:29 --> 00:36:31 an incredible diversity and variety of simple
00:36:31 --> 00:36:34 life, but that's all you had. So only about
00:36:34 --> 00:36:36 500 million years ago, give or take, that,
00:36:36 --> 00:36:39 you start to get complex life. So the
00:36:39 --> 00:36:41 argument following that would be if
00:36:41 --> 00:36:44 Mars had life and, um, if that
00:36:44 --> 00:36:46 life followed a similar pathway to the Earth,
00:36:47 --> 00:36:49 then you would expect that that ancient life
00:36:49 --> 00:36:51 would all have been simple life. Now, the
00:36:51 --> 00:36:52 other thing that argues for that is if you
00:36:52 --> 00:36:54 look around on the Earth today, we've got
00:36:54 --> 00:36:56 life in abundance all over the place. But the
00:36:56 --> 00:36:58 more complex the life is, the more limited
00:36:58 --> 00:37:00 the variety of environments that it can exist
00:37:00 --> 00:37:02 in, if that makes sense.
00:37:02 --> 00:37:03 Andrew Dunkley: Yeah.
00:37:03 --> 00:37:06 Jonti Horner: So obviously simple life can exist in a
00:37:06 --> 00:37:09 wider variety of conditions and, um, will
00:37:09 --> 00:37:12 exist earlier than complex life. And
00:37:12 --> 00:37:15 so the argument then would be with all those
00:37:15 --> 00:37:16 assumptions, and I know I'm doing a lot of
00:37:16 --> 00:37:18 COVID your own ass here, but with the
00:37:18 --> 00:37:20 assumption that everything followed the way
00:37:20 --> 00:37:22 that things went on Earth, my expectation
00:37:22 --> 00:37:24 would have been that Gale Crater could well
00:37:24 --> 00:37:26 have been teeming with life, but it would
00:37:26 --> 00:37:27 have been simple life. It would have been
00:37:27 --> 00:37:29 single celled life. Now, single celled life
00:37:29 --> 00:37:32 still lives, a very vibrant and
00:37:32 --> 00:37:34 diverse set of lives. So there will be things
00:37:34 --> 00:37:36 interfering with each other and eating each
00:37:36 --> 00:37:38 other and all that kind of happy stuff going
00:37:38 --> 00:37:41 on. But it's likely that there
00:37:41 --> 00:37:44 weren't giant sharks or octo sharks
00:37:44 --> 00:37:46 or whatever you know, swimming around in the
00:37:46 --> 00:37:49 ocean in Gale Crater. And I suspect that if
00:37:49 --> 00:37:51 there had have been, we'd already possibly be
00:37:51 --> 00:37:53 finding evidence in the form of fossils. I
00:37:53 --> 00:37:56 may be wrong on that, but I suspect that the
00:37:56 --> 00:37:58 fact we haven't yet got definitive proof of
00:37:58 --> 00:38:01 ancient life on Mars suggests that the life
00:38:01 --> 00:38:03 that was there, if it was there, uh, was
00:38:03 --> 00:38:05 simple life and single celled life rather
00:38:05 --> 00:38:08 than complex stuff. But I stand to be
00:38:08 --> 00:38:09 corrected on that. I look forward to the
00:38:09 --> 00:38:12 confirmation of the discovery of ancient
00:38:12 --> 00:38:14 fossils on Mars, if we ever get there.
00:38:14 --> 00:38:15 Confirmation of life elsewhere will be
00:38:15 --> 00:38:18 awesome. So it might be worth getting Anita
00:38:18 --> 00:38:21 back on the show, uh, in a decade or so
00:38:21 --> 00:38:23 to sing the sequel is now that we know there
00:38:23 --> 00:38:25 Was life there? What was it like? Yeah, yeah.
00:38:25 --> 00:38:28 Andrew Dunkley: Um, but I think we will
00:38:28 --> 00:38:31 find something somewhere. Probably Mars,
00:38:31 --> 00:38:33 but maybe on some of the ice moons
00:38:34 --> 00:38:37 further out. But there's got to be
00:38:37 --> 00:38:39 something. Uh, I think it'll be microbial, as
00:38:39 --> 00:38:42 you said. But it's just,
00:38:43 --> 00:38:45 you look how life just grabs on
00:38:46 --> 00:38:49 on Earth given
00:38:49 --> 00:38:51 minimal opportunity. And
00:38:51 --> 00:38:53 I think that that same
00:38:55 --> 00:38:57 thing exists in the universe
00:38:57 --> 00:39:00 elsewhere. Um, life, if there is
00:39:00 --> 00:39:03 just a small opportunity, it will grow
00:39:03 --> 00:39:06 and I think that's what we will find. But,
00:39:06 --> 00:39:09 uh, whether or not we find another
00:39:10 --> 00:39:12 so called intelligent
00:39:13 --> 00:39:16 place in the universe or an intelligent
00:39:16 --> 00:39:19 species, that's a bigger call
00:39:19 --> 00:39:21 and a completely different ball game indeed.
00:39:21 --> 00:39:23 Uh, thank you for the question, Anita. And if
00:39:23 --> 00:39:25 you would like to listen to the music that
00:39:25 --> 00:39:27 Jonti, uh, was referring to, you can go to
00:39:27 --> 00:39:30 YouTube Music, do a search for Nightwish,
00:39:30 --> 00:39:32 Shoemaker, uh, the official lyric video.
00:39:33 --> 00:39:35 Um, they've got 1.82 million
00:39:35 --> 00:39:38 subscribers. Yeah, it's extraordinary.
00:39:38 --> 00:39:41 Jonti Horner: It's a style of music that isn't really
00:39:41 --> 00:39:43 widely known in Australia. So when I've gone
00:39:43 --> 00:39:44 to see them on the odd occasion, they've come
00:39:44 --> 00:39:46 over here. We've been down at the Tivoli in
00:39:46 --> 00:39:48 Brisbane, which is kind of a thousand people.
00:39:49 --> 00:39:50 When they go anywhere else in the world,
00:39:50 --> 00:39:52 they're doing packed stadiums with a hundred
00:39:52 --> 00:39:55 thousand plus. So it's a different genre.
00:39:55 --> 00:39:58 Um, they, along with a group called Epica and
00:39:58 --> 00:40:00 a male group called Camelot, are probably the
00:40:00 --> 00:40:02 three leading light groups in that genre of
00:40:02 --> 00:40:05 symphonic metal, which is the interface of
00:40:05 --> 00:40:07 opera and rock effectively. Um,
00:40:07 --> 00:40:10 but they've had a number of scientifically
00:40:10 --> 00:40:12 themed songs over the years. In fact, there's
00:40:12 --> 00:40:14 one that I have as recommended reading stroke
00:40:14 --> 00:40:16 listening for my undergrad students. That's
00:40:16 --> 00:40:19 kind of of a 20 odd minute long story of the
00:40:19 --> 00:40:21 evolution of the planetary system and life on
00:40:21 --> 00:40:23 Earth and all the rest of it. So they've done
00:40:23 --> 00:40:23 interesting things.
00:40:24 --> 00:40:25 Andrew Dunkley: I'm sure they have.
00:40:25 --> 00:40:26 Jonti Horner: All right. Shoemakers are good. Listen.
00:40:27 --> 00:40:29 Andrew Dunkley: Excellent. All right, uh, thanks to everyone
00:40:29 --> 00:40:32 who contributed. If you would like to send a
00:40:32 --> 00:40:34 question into, um, the Space
00:40:35 --> 00:40:36 Nuts website, just go to
00:40:36 --> 00:40:39 spacenutspodcast.com or spacenuts
00:40:39 --> 00:40:42 IO and click on the AMA
00:40:42 --> 00:40:44 button at the top and send us your, uh, text
00:40:44 --> 00:40:47 or audio question. Don't forget to tell us,
00:40:47 --> 00:40:48 tell us who you are and where you're from,
00:40:49 --> 00:40:51 uh, and leave your email address so we can
00:40:51 --> 00:40:52 spam the hell out of you. No, I'm only
00:40:52 --> 00:40:55 kidding. Although I think that is part of the
00:40:55 --> 00:40:58 deal. M. We'll see. But, um,
00:40:58 --> 00:41:00 yes. And, uh, uh, Guess what? Huw in the
00:41:00 --> 00:41:03 studio just turned up. Hi, Huw. Bye,
00:41:03 --> 00:41:06 Huw. And thanks to you,
00:41:06 --> 00:41:08 Jonti. We'll catch you on the next episode.
00:41:08 --> 00:41:09 Jonti Horner: It's a pleasure. Looking forward to it.
00:41:10 --> 00:41:12 Andrew Dunkley: Uh, Johnny Horner, professor of astrophysics,
00:41:12 --> 00:41:15 uh, at the University of Southern Queensland.
00:41:15 --> 00:41:17 And we thank him. We thank everybody and
00:41:18 --> 00:41:20 thank you. Uh, uh, and from me, Andrew
00:41:20 --> 00:41:23 Dunkley, thank you for your company. We'll
00:41:23 --> 00:41:24 catch you on the very next episode of Space
00:41:24 --> 00:41:25 Nuts.
00:41:25 --> 00:41:26 Jonti Horner: Bye. Bye.
00:41:27 --> 00:41:29 You'll be listening to the Space Nuts
00:41:29 --> 00:41:32 podcast, available at
00:41:32 --> 00:41:34 Apple Podcasts, Spotify,
00:41:34 --> 00:41:37 iHeartRadio, or your favorite podcast
00:41:37 --> 00:41:39 player. You can also stream
00:41:39 --> 00:41:41 ondemand@bytes.com.
00:41:41 --> 00:41:43 Andrew Dunkley: This has been another quality podcast
00:41:43 --> 00:41:45 production from bytes.
00:41:45 --> 00:41:45 Jonti Horner: Com.
00:41:45 --> 00:41:45 Jonti Horner: Um.