Frozen Frontiers: Snowball Earth, Dinosaur Origins, and Hubble Tension
In this captivating holiday episode of Space Nuts, hosts Andrew Dunkley and Professor Fred Watson embark on a journey through time and space, discussing the intriguing concept of Snowball Earth, the origins of the dinosaur-killing asteroid, and the ongoing debate surrounding the Hubble tension in cosmology.
Episode Highlights:
- Snowball Earth: Andrew and Fred explore the fascinating theory of Snowball Earth, a period when our planet was completely frozen over, and how recent geological findings in Scotland and Australia shed light on this icy epoch.
- Dinosaur-Killing Asteroid Origins: The hosts delve into the latest research pinpointing the Chicxulub impactor's origins within the asteroid belt, revealing the chemical markers that help trace its journey through the solar system.
- The Hubble Tension: A discussion on the so-called crisis in cosmology, as the hosts dissect the differing measurements of the universe's expansion rate and how new data from the James Webb Space Telescope may provide clarity.
- Listener Questions: The episode wraps up with engaging listener questions, including a fascinating inquiry about the impact of a frozen Earth on its diameter, prompting a thoughtful discussion on planetary changes over time.
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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 --> 00:00:02 Andrew Dunkley: Space Nuts is taking a bit of a break at the
00:00:02 --> 00:00:04 moment. Fred and I will be back in the not
00:00:04 --> 00:00:06 too distant future with fresh episodes. In
00:00:06 --> 00:00:09 the meantime, enjoy some of the key episodes
00:00:09 --> 00:00:11 that we have presented over the years.
00:00:12 --> 00:00:14 Major events in astronomy and space
00:00:15 --> 00:00:17 science. And we'll see you real soon.
00:00:18 --> 00:00:21 Space Nuts. Hi there. Thanks for joining us
00:00:21 --> 00:00:23 on another episode of Space Nuts. Andrew
00:00:23 --> 00:00:25 Dunkley here and it's good to have your
00:00:25 --> 00:00:28 company. Coming up on this episode we're
00:00:28 --> 00:00:31 going to be looking at Snowball Earth.
00:00:31 --> 00:00:34 There was a time where it was just a frozen
00:00:34 --> 00:00:37 sphere of nothingness for well, billions
00:00:37 --> 00:00:39 of years. now they have a new theory about
00:00:39 --> 00:00:41 that and it's no Irish joke.
00:00:42 --> 00:00:45 There's a clue in there. the dinosaur
00:00:45 --> 00:00:48 asteroids origin has been revealed. Yep, the
00:00:48 --> 00:00:51 thing that started the getting
00:00:51 --> 00:00:53 rid of them all across the planet. We know
00:00:53 --> 00:00:56 where it came from. And the so called
00:00:56 --> 00:00:59 crisis in cosmology might not be a crisis at
00:00:59 --> 00:01:01 all. We're talking about the Hubble tension.
00:01:01 --> 00:01:04 We'll talk about all of that on this episode
00:01:04 --> 00:01:06 of space nuts. 15 seconds.
00:01:06 --> 00:01:09 Professor Fred Watson: Guidance is internal. 10, 9.
00:01:10 --> 00:01:13 ignition sequence start. Space nuts. 5,
00:01:13 --> 00:01:16 4, 3. 2. 1. 2, 3, 4, 5,
00:01:16 --> 00:01:17 5, 4, 3, 2, 1.
00:01:17 --> 00:01:19 Andrew Dunkley: Space nuts.
00:01:19 --> 00:01:21 Professor Fred Watson: Astronauts report it feels good.
00:01:21 --> 00:01:24 Andrew Dunkley: And to help us unravel all of that,
00:01:24 --> 00:01:27 decipher it and use his code book to
00:01:27 --> 00:01:29 figure a few more things out, is Professor
00:01:29 --> 00:01:31 Fred Watson, astronomer at large. Hello Fred.
00:01:32 --> 00:01:34 Professor Fred Watson: Hello Andrew. Keep up the good work there.
00:01:34 --> 00:01:35 It's going very well.
00:01:36 --> 00:01:38 Andrew Dunkley: It's good to see you.
00:01:38 --> 00:01:41 I just, I thought I'd sort of start out of
00:01:41 --> 00:01:44 left field because I spotted a
00:01:44 --> 00:01:46 story, only today actually,
00:01:47 --> 00:01:49 which dovetails with something we talked
00:01:49 --> 00:01:52 about some time ago. And that was the work
00:01:52 --> 00:01:54 that's being done to perfect
00:01:55 --> 00:01:57 engine technology to achieve greater
00:01:57 --> 00:02:00 speeds, for interstellar travel
00:02:00 --> 00:02:03 in years to come. Or maybe not interstellar,
00:02:03 --> 00:02:05 but interplanetary perhaps. And we know NASA
00:02:05 --> 00:02:08 is working on this kind of technology to
00:02:09 --> 00:02:11 create really
00:02:12 --> 00:02:15 fast and high performance engines. They're
00:02:15 --> 00:02:17 working with I think it's General Electric to
00:02:17 --> 00:02:20 achieve that. they may have been Gesumped.
00:02:20 --> 00:02:21 Fred, have you heard about this?
00:02:22 --> 00:02:23 Professor Fred Watson: no.
00:02:24 --> 00:02:27 Andrew Dunkley: the Chinese, the Chinese claim to have
00:02:27 --> 00:02:29 developed a new engine
00:02:30 --> 00:02:32 that can achieve a speed of
00:02:33 --> 00:02:35 12 miles per hour
00:02:35 --> 00:02:38 or 19 kilometers an hour.
00:02:38 --> 00:02:41 And the aircraft can reach an altitude of 30
00:02:41 --> 00:02:44 kilometers. Now you compare that to the
00:02:44 --> 00:02:46 Concorde, it's Mach
00:02:46 --> 00:02:49 16 versus Mach 2, which
00:02:49 --> 00:02:52 is an extraordinary claim. Now apparently
00:02:52 --> 00:02:54 they've released a paper which has been peer
00:02:54 --> 00:02:57 Reviewed, from what I understand. and it's
00:02:57 --> 00:03:00 not April 1st, I'm confident of that. So
00:03:00 --> 00:03:03 they reckon that they've, they've made
00:03:03 --> 00:03:06 this leap in technology to
00:03:06 --> 00:03:08 develop a Max 16 engine.
00:03:09 --> 00:03:11 And just think of this, Fred. You'd be able
00:03:11 --> 00:03:13 to fly from Sydney to New York
00:03:14 --> 00:03:15 in 50 minutes.
00:03:16 --> 00:03:18 Professor Fred Watson: Yes, that's what it was, 50 minutes.
00:03:20 --> 00:03:23 Andrew Dunkley: that's extraordinary if it's real. And I
00:03:23 --> 00:03:25 don't see why it wouldn't be, but you never
00:03:25 --> 00:03:28 know with these things. But apparently,
00:03:28 --> 00:03:30 according to the paper, the engine operates
00:03:30 --> 00:03:32 in two modes. There's a continuous rotating
00:03:32 --> 00:03:34 detonation engine, which is a scary thing in
00:03:34 --> 00:03:36 itself by the sound of it, which will get it
00:03:36 --> 00:03:38 to Mach 7. And you know, the air and
00:03:38 --> 00:03:41 the fuel create a rotating shock wave with
00:03:41 --> 00:03:44 continuous thrust and then a straight line
00:03:44 --> 00:03:46 oblique detonation engine which
00:03:46 --> 00:03:49 fires above mark seven and pushes it all
00:03:49 --> 00:03:52 the way to Mach 16. it
00:03:52 --> 00:03:54 sounds amazing. Sounds amazing.
00:03:55 --> 00:03:58 how far short they are of getting this
00:03:58 --> 00:04:00 into production, I don't know. But, it
00:04:00 --> 00:04:02 certainly sounds like it's in development.
00:04:03 --> 00:04:06 That would be amazing to be able to achieve
00:04:06 --> 00:04:08 those kinds of speeds. it would revolutionize
00:04:08 --> 00:04:09 travel around the world.
00:04:10 --> 00:04:12 Professor Fred Watson: But it's been done already.
00:04:15 --> 00:04:17 Yeah, the British have been working on this
00:04:17 --> 00:04:20 for decades now with,
00:04:21 --> 00:04:24 it's an air breathing, it's a hybrid
00:04:24 --> 00:04:26 engine that breathes air
00:04:27 --> 00:04:29 at low altitudes and turns into a rocket
00:04:29 --> 00:04:31 motor when you get above the Earth's
00:04:31 --> 00:04:31 atmosphere.
00:04:31 --> 00:04:34 Andrew Dunkley: Yeah, I think I did hear about that. I didn't
00:04:34 --> 00:04:35 know it got to those sorts of speeds.
00:04:35 --> 00:04:38 Professor Fred Watson: Yeah, well, it's capable of entering orbit,
00:04:38 --> 00:04:40 so it can get up to, you know, 26
00:04:40 --> 00:04:43 kilometers an hour. But it's then acting as a
00:04:43 --> 00:04:46 rocket motor. So it's The project was called,
00:04:47 --> 00:04:49 well, Hotol was the style of thing,
00:04:49 --> 00:04:52 horizontal takeoff and landing. so it
00:04:52 --> 00:04:55 flies like a plane, takes off like a plane
00:04:55 --> 00:04:58 with the air burning. Jet engines just
00:04:58 --> 00:05:01 gradually accelerates, clicks, over
00:05:01 --> 00:05:04 into being a, rocket
00:05:04 --> 00:05:06 motor, when the atmosphere gets too rarefied
00:05:06 --> 00:05:09 and then sends you up to orbit. but as
00:05:09 --> 00:05:11 I remember right, I think it's called the
00:05:11 --> 00:05:13 Sabre, the engine. If I remember rightly,
00:05:13 --> 00:05:15 it's Sabre. But the big problem
00:05:16 --> 00:05:19 was, keeping the air
00:05:19 --> 00:05:21 cool. And there was some. The
00:05:21 --> 00:05:23 main breakthrough was apparently a heat
00:05:23 --> 00:05:26 exchanger that could bring the temperature of
00:05:26 --> 00:05:29 the air, down from 700
00:05:29 --> 00:05:32 degrees Celsius or something, to liquid
00:05:32 --> 00:05:34 nitrogen temperatures in something like a
00:05:34 --> 00:05:36 thousandth of a second as it passes through
00:05:36 --> 00:05:39 the engine. and that was a big breakthrough.
00:05:39 --> 00:05:41 Now I think we've spoken about it before a
00:05:41 --> 00:05:42 long, long time ago because there hasn't
00:05:42 --> 00:05:44 really been much news. It was being supported
00:05:44 --> 00:05:46 by the British government. I don't know
00:05:46 --> 00:05:49 whether that support has now dwindled,
00:05:49 --> 00:05:52 because it would be, you know, the idea about
00:05:52 --> 00:05:54 this was economics. It was to be able to have
00:05:54 --> 00:05:56 the same spacecraft that will take you up
00:05:56 --> 00:05:58 there and bring you back and was completely
00:05:58 --> 00:06:00 reusable. And to some extent I think,
00:06:01 --> 00:06:04 Elon Musk, SpaceX and their Falcon 9s have
00:06:04 --> 00:06:06 kind of cornered the market on that because
00:06:06 --> 00:06:09 they've now got reusable spacecraft which are
00:06:09 --> 00:06:11 routinely being used every day, almost.
00:06:12 --> 00:06:14 So maybe there's no space for it. But yeah,
00:06:15 --> 00:06:17 extraordinary technology and I'm sure the
00:06:17 --> 00:06:20 Chinese technology is, is above board what
00:06:20 --> 00:06:21 you've just been describing.
00:06:21 --> 00:06:23 Andrew Dunkley: Yeah, it's from the Beijing Power Machinery
00:06:23 --> 00:06:25 Institute and they've published their paper
00:06:25 --> 00:06:28 in the Chinese Journal of Propulsion
00:06:28 --> 00:06:30 Technology. I can, I can see a problem with
00:06:30 --> 00:06:32 it though. Let's say they do create an
00:06:32 --> 00:06:34 airliner, that can do that trip in 50 minutes
00:06:34 --> 00:06:37 from New York to Sydney, for example. You'd
00:06:37 --> 00:06:39 leave at 7 o' clock in the morning in New
00:06:39 --> 00:06:42 York. You'd arrive at 11pm 50 minutes later
00:06:42 --> 00:06:44 in Sydney. So you get up
00:06:45 --> 00:06:48 and get on the plane then get to Sydney and
00:06:48 --> 00:06:49 then have to go to bed wide away.
00:06:49 --> 00:06:52 Professor Fred Watson: Yes, that's right.
00:06:52 --> 00:06:53 That's the issue. It's always the issue.
00:06:54 --> 00:06:56 Andrew Dunkley: It would make jet lag all the more worse.
00:06:57 --> 00:06:59 Professor Fred Watson: But you know, I think I'd put up with that
00:06:59 --> 00:07:01 rather than have all those 20 hours.
00:07:02 --> 00:07:05 Andrew Dunkley: Yeah, 20 hour flight. Yeah, I've got one of
00:07:05 --> 00:07:06 those coming up very soon actually.
00:07:06 --> 00:07:09 Professor Fred Watson: You do, that's right, yeah, yeah, yeah.
00:07:09 --> 00:07:11 Andrew Dunkley: yeah, to watch this space story, but I just
00:07:11 --> 00:07:13 find it fascinating these, these kinds of
00:07:13 --> 00:07:14 leaps in technology.
00:07:15 --> 00:07:17 Let's move on. a new theory about
00:07:17 --> 00:07:20 snowball Earth. Fred, I said there's
00:07:20 --> 00:07:22 there's no Irish joke attached to this and
00:07:22 --> 00:07:24 there's a good reason I said that.
00:07:25 --> 00:07:27 Professor Fred Watson: Which I'm probably going to sidestep
00:07:27 --> 00:07:30 completely. it's about rocks in Scotland and
00:07:30 --> 00:07:30 in Australia.
00:07:32 --> 00:07:33 Andrew Dunkley: I thought it was, I thought they said there
00:07:33 --> 00:07:35 was some of these rocks in Ireland as well.
00:07:35 --> 00:07:37 Professor Fred Watson: Yeah, I think, I think there are. I think
00:07:37 --> 00:07:38 that's right. that' think we've got.
00:07:38 --> 00:07:40 Andrew Dunkley: That's the loose connection I made with.
00:07:42 --> 00:07:45 Professor Fred Watson: also includes rocks in Namibia, and North
00:07:45 --> 00:07:47 America, as well as Scotland,
00:07:48 --> 00:07:51 you're probably right in Ireland because it's
00:07:51 --> 00:07:53 the west of Scotland where these, where these
00:07:53 --> 00:07:55 rocks are. That have recently been analyzed.
00:07:56 --> 00:07:58 and I mean, it's an interesting story. I've
00:07:58 --> 00:08:00 often wondered about Snowball Earth. I never
00:08:00 --> 00:08:03 really looked at. At the details of it. So
00:08:03 --> 00:08:06 it's a period of about 60
00:08:06 --> 00:08:09 million years ago. Oh, sorry, 60
00:08:09 --> 00:08:12 million years long. But it was a long
00:08:12 --> 00:08:14 time ago. It began 700 million years ago,
00:08:15 --> 00:08:18 in fact, probably more like 720 million
00:08:18 --> 00:08:20 years ago and lasted until about
00:08:20 --> 00:08:23 635 million years ago. And it's called
00:08:23 --> 00:08:26 the cryogenian. Cryogenian geological
00:08:26 --> 00:08:28 period. And anything with cryo in the front
00:08:28 --> 00:08:30 of it means it's frozen solid.
00:08:33 --> 00:08:35 so I thought, well, how do we know this and
00:08:36 --> 00:08:39 the way we know it and the
00:08:39 --> 00:08:42 way we know that, glacial ice covered the
00:08:42 --> 00:08:44 whole planet is because you
00:08:44 --> 00:08:47 can see in the geology the
00:08:47 --> 00:08:49 effects of glaciation,
00:08:49 --> 00:08:52 everywhere. It's not just, you know,
00:08:52 --> 00:08:55 I grew up in a country where, 10 years
00:08:55 --> 00:08:56 ago, the whole of the northern part of
00:08:56 --> 00:08:59 Britain was under ice. And so my. All
00:08:59 --> 00:09:01 my school lessons were about glacial
00:09:01 --> 00:09:04 features, in the north of England. And
00:09:04 --> 00:09:07 so, so you could tell from rocks,
00:09:07 --> 00:09:10 whether something has been glaciated.
00:09:10 --> 00:09:13 And that's how we know everywhere there is
00:09:13 --> 00:09:16 this layer of rock, ah, corresponding to,
00:09:16 --> 00:09:19 looking back, you know, 6, 6 or 700
00:09:19 --> 00:09:21 million years where you see the evidence of
00:09:21 --> 00:09:24 glaciation. and so the interpretation of that
00:09:24 --> 00:09:27 is that, you had an
00:09:27 --> 00:09:30 ice age that was the. Put it, the
00:09:30 --> 00:09:33 grandfather of all ice ages. the whole planet
00:09:33 --> 00:09:35 was frozen. and so
00:09:35 --> 00:09:38 the new research concerns, evidence from
00:09:38 --> 00:09:40 rocks in Scotland. and what's
00:09:40 --> 00:09:43 remarkable is that, the
00:09:43 --> 00:09:46 sort of the glacial evidence there
00:09:46 --> 00:09:49 shows up really clearly, for some
00:09:49 --> 00:09:51 reason that has been preserved very well,
00:09:52 --> 00:09:54 there, you know, underneath the sediments
00:09:54 --> 00:09:56 that were dropped on top of it,
00:09:57 --> 00:10:00 later on. But, the bottom line about.
00:10:02 --> 00:10:04 Professor Fred Watson: The reason why we got this ice age
00:10:05 --> 00:10:07 is a question. I'm not sure that in the
00:10:07 --> 00:10:10 article I sent you, it goes into detail about
00:10:10 --> 00:10:13 it. but the thinking is that
00:10:13 --> 00:10:16 we were seeing a period when,
00:10:16 --> 00:10:19 or before this period, we were seeing a time
00:10:20 --> 00:10:23 when, volcanic rocks
00:10:25 --> 00:10:28 were being, eroded. They were being weathered
00:10:28 --> 00:10:30 very rapidly. And apparently these were
00:10:30 --> 00:10:33 particularly in Canada. these volcanic rocks,
00:10:33 --> 00:10:35 I'm looking back now perhaps 720
00:10:35 --> 00:10:38 million years. they were
00:10:38 --> 00:10:41 eroded by weathering. And that process
00:10:41 --> 00:10:44 sucks carbon dioxide out of the atmosphere.
00:10:45 --> 00:10:48 and so, what you're seeing is
00:10:48 --> 00:10:50 a situation where the atmospheric
00:10:50 --> 00:10:53 carbon dioxide is lower
00:10:53 --> 00:10:56 than normal. And in fact, it is
00:10:56 --> 00:10:58 probably was probably about half,
00:10:59 --> 00:11:02 what today's level Is today's level's in
00:11:02 --> 00:11:04 the region of 400 parts per million of carbon
00:11:04 --> 00:11:06 dioxide in the atmosphere. And that's enough
00:11:06 --> 00:11:08 to blanket our planet and keep the
00:11:08 --> 00:11:11 temperature stable. unless you put more in,
00:11:11 --> 00:11:13 in which case the temperature goes up, as you
00:11:13 --> 00:11:16 know. But if, you drop too far down,
00:11:16 --> 00:11:19 then you get an ice ball. they estimate
00:11:19 --> 00:11:22 the atmospheric carbon dioxide levels,
00:11:24 --> 00:11:26 back in the cryogenic period or
00:11:26 --> 00:11:29 cryogenonian period, they estimate
00:11:29 --> 00:11:31 they were below 200 parts per million. And
00:11:31 --> 00:11:33 what that does is lets the heat just radiate
00:11:33 --> 00:11:36 out into the, into space and you
00:11:36 --> 00:11:39 lose heat. The Earth's, surface becomes very
00:11:39 --> 00:11:41 cold. and basically, you get the
00:11:41 --> 00:11:43 snowball Earth, you get an Earth that is
00:11:43 --> 00:11:44 covered with ice.
00:11:46 --> 00:11:47 it's the same sort of thing that we think
00:11:47 --> 00:11:49 happened on Mars. Mars is very low carbon
00:11:49 --> 00:11:51 dioxide content and that's why we think it
00:11:51 --> 00:11:54 got cold and dry rather than warm and white
00:11:54 --> 00:11:55 as it once was.
00:11:56 --> 00:11:58 Andrew Dunkley: The other, there's a lot of moving parts to
00:11:58 --> 00:12:00 this story, but one of the things I found
00:12:01 --> 00:12:03 most interesting was if this
00:12:04 --> 00:12:06 mega freeze hadn't happened,
00:12:07 --> 00:12:09 life as we know it may not have developed
00:12:10 --> 00:12:12 because up until this time it was just
00:12:12 --> 00:12:14 microbial. Just that was it.
00:12:15 --> 00:12:18 Professor Fred Watson: That's, that's correct. so, and the thinking,
00:12:18 --> 00:12:20 yes, it was, it was single celled organisms
00:12:20 --> 00:12:23 until that time. And they were around for
00:12:24 --> 00:12:25 you know, 3 billion years or so.
00:12:26 --> 00:12:28 nothing happened except these single celled
00:12:28 --> 00:12:30 organisms, principally
00:12:30 --> 00:12:33 cyanobacteria, they just did their thing and
00:12:33 --> 00:12:35 got on with life, but didn't evolve in any
00:12:35 --> 00:12:38 way. but the end this,
00:12:38 --> 00:12:40 this end of the glacial period
00:12:41 --> 00:12:44 was such a sort of rapid
00:12:44 --> 00:12:47 climate change by the standards of the,
00:12:47 --> 00:12:50 of the time, by geological standards, that
00:12:50 --> 00:12:52 the thinking is that you'd got almost
00:12:53 --> 00:12:56 an arms race, to adapt,
00:12:58 --> 00:13:00 to this new situation where
00:13:01 --> 00:13:02 the microbes are not permanently in deep
00:13:02 --> 00:13:05 freeze, you've got a warming climate
00:13:06 --> 00:13:08 and the evolution of the microbes kicks in
00:13:08 --> 00:13:11 at a much higher level than it was before.
00:13:11 --> 00:13:14 And that is where we think that the multi
00:13:14 --> 00:13:16 celled organism started to be formed. And
00:13:17 --> 00:13:19 that's what are, the ancestors of all the
00:13:19 --> 00:13:20 animals that we see today.
00:13:20 --> 00:13:23 Andrew Dunkley: Yeah, so basically those who survived the
00:13:23 --> 00:13:25 thaw or adapted to it,
00:13:25 --> 00:13:28 created life as we know it. Yeah, that's this
00:13:28 --> 00:13:31 extraordinary, sort
00:13:31 --> 00:13:33 of factor to come out of it. The other thing
00:13:33 --> 00:13:36 I, and correct me if I'm wrong, but, these
00:13:36 --> 00:13:39 rocks we were talking about in Ireland and
00:13:39 --> 00:13:41 Scotland and Australia and everywhere else,
00:13:41 --> 00:13:44 the reason that these are so different is I
00:13:44 --> 00:13:46 believe these were rocks that actually stuck
00:13:46 --> 00:13:49 out of the ice. Is that
00:13:49 --> 00:13:50 correct?
00:13:51 --> 00:13:54 Professor Fred Watson: During that period they may have done,
00:13:54 --> 00:13:57 or at least been subject to less
00:13:57 --> 00:14:00 glacial activity. So yes, they may
00:14:00 --> 00:14:03 have, you know, had only a thin layer of ice
00:14:03 --> 00:14:05 over them rather than be under kilometers of
00:14:05 --> 00:14:08 ice. so I think you're right there.
00:14:08 --> 00:14:11 And just to confirm, you're quite
00:14:11 --> 00:14:12 right that some of these rocks are in Ireland
00:14:12 --> 00:14:15 as well. I hadn't spotted that Andrew, in my
00:14:15 --> 00:14:18 reading of the paper. but yes, so you've got,
00:14:20 --> 00:14:22 particularly you've got these rocks
00:14:23 --> 00:14:26 on some of the Scottish islands. These are
00:14:26 --> 00:14:29 small islands called the Gavelis. and it's
00:14:28 --> 00:14:30 basically in the west of Scotland.
00:14:32 --> 00:14:34 it's under the Portaske formation. This is a,
00:14:34 --> 00:14:37 ah, geological area. Portaske, very well
00:14:37 --> 00:14:38 known to Scots people because it's the name
00:14:38 --> 00:14:41 of a well known pipe tune. so let me quote
00:14:41 --> 00:14:44 from one of the authors of this work. and
00:14:44 --> 00:14:46 he's actually a Ph.D.
00:14:46 --> 00:14:49 candidate at the
00:14:50 --> 00:14:52 university, College London. the layers of
00:14:52 --> 00:14:55 rocks exposed on the Gyvelichs are globally
00:14:55 --> 00:14:58 unique. Underneath the rocks laid down during
00:14:58 --> 00:15:00 the unimaginable cold of the glaciation,
00:15:01 --> 00:15:04 70 meters of older carbonate rocks formed
00:15:04 --> 00:15:06 in tropical waters. These layers
00:15:06 --> 00:15:09 record a tropical marine environment with
00:15:09 --> 00:15:11 flourishing cyanobacterial life that
00:15:11 --> 00:15:13 gradually became cooler, marking the end of a
00:15:13 --> 00:15:16 billion years or so of a temperate climate on
00:15:16 --> 00:15:19 Earth. most areas of the world are missing
00:15:19 --> 00:15:21 this remarkable transition because the
00:15:21 --> 00:15:24 ancient glaciers scraped and eroded
00:15:24 --> 00:15:26 the way the rocks underneath. But in
00:15:26 --> 00:15:28 Scotland, by some miracle, the transition can
00:15:28 --> 00:15:30 be seen. And I think that's underlining what
00:15:30 --> 00:15:32 you said. They were either sticking up
00:15:32 --> 00:15:34 through the ice or they weren't particularly
00:15:34 --> 00:15:37 deeply covered by ice. so it's minerals
00:15:37 --> 00:15:40 and radiometric dating of the minerals that
00:15:40 --> 00:15:43 have allowed this discovery to be
00:15:43 --> 00:15:43 made.
00:15:44 --> 00:15:46 Andrew Dunkley: Yeah, it's incredible, isn't it? All the
00:15:46 --> 00:15:48 answers are right there in front of us in the
00:15:48 --> 00:15:49 dirt sometimes.
00:15:50 --> 00:15:52 Professor Fred Watson: Simple as that. That's how we,
00:15:52 --> 00:15:55 we know so much about the history of
00:15:55 --> 00:15:57 not just our planet but the, you know, the,
00:15:57 --> 00:15:59 the other planets of the solar system. Just
00:15:59 --> 00:16:01 learn from looking at the rocks. That's
00:16:01 --> 00:16:02 right, yeah.
00:16:02 --> 00:16:05 Andrew Dunkley: Fantastic. if you'd like to read the article
00:16:05 --> 00:16:08 or chase up that story, it's on the cosmos
00:16:08 --> 00:16:11 magazine.com website. This is
00:16:11 --> 00:16:13 Space Nuts Andrew Dunkley here with Professor
00:16:13 --> 00:16:14 Brad Watson.
00:16:17 --> 00:16:18 Roger, your labs right here.
00:16:18 --> 00:16:19 Professor Fred Watson: Also Space Nuts.
00:16:20 --> 00:16:23 Andrew Dunkley: speaking of dirt, Fred, we've got
00:16:23 --> 00:16:25 the dirt on the dinosaur asteroid. we
00:16:25 --> 00:16:28 now know, thanks to a new study where it came
00:16:28 --> 00:16:30 from. This is fascinating too.
00:16:31 --> 00:16:33 Professor Fred Watson: It is, that's right. and you know, it's not
00:16:33 --> 00:16:36 that long ago that people were really still
00:16:36 --> 00:16:38 speculating about where the remnants of this
00:16:38 --> 00:16:41 asteroid was. we're now pretty certain
00:16:41 --> 00:16:43 that it's in the Chicxulub,
00:16:44 --> 00:16:46 basin in the Gulf of Mexico. That that
00:16:46 --> 00:16:49 is the site which actually was
00:16:49 --> 00:16:52 the impact site of this asteroid. So what
00:16:52 --> 00:16:55 you can do is you can look at the rocks,
00:16:55 --> 00:16:58 that you find in that region. Once again,
00:16:58 --> 00:17:01 we're looking down at the dirt, but
00:17:01 --> 00:17:03 basically look to see whether we know of
00:17:03 --> 00:17:06 anything like it out there
00:17:06 --> 00:17:09 in the solar system. and the
00:17:10 --> 00:17:13 bottom line is that yes, we do find
00:17:13 --> 00:17:16 that, in particular, and this is
00:17:16 --> 00:17:18 work being done at the University of Cologne
00:17:18 --> 00:17:19 in Germany,
00:17:21 --> 00:17:24 the element ruthenium,
00:17:25 --> 00:17:27 is basically a chemical
00:17:27 --> 00:17:30 marker, if I can put it that way, that is
00:17:30 --> 00:17:33 found in the debris around the
00:17:33 --> 00:17:36 Chicxulub impactor, and apparently in
00:17:36 --> 00:17:38 other sediments around the world. Because the
00:17:38 --> 00:17:40 debris from that explosion spread all around
00:17:40 --> 00:17:43 the world. It was so, you know,
00:17:44 --> 00:17:45 ah, such a major
00:17:47 --> 00:17:49 piece of explosive material.
00:17:50 --> 00:17:52 It was only explosive because it hit the
00:17:52 --> 00:17:55 ground at a very high speed, probably 30
00:17:55 --> 00:17:57 or 40 kilometers per second. but the
00:17:57 --> 00:18:00 fingerprint of ruthenium has been found in
00:18:00 --> 00:18:02 that debris and it turns out
00:18:03 --> 00:18:05 that that coincides with
00:18:06 --> 00:18:08 rocks in m, the main
00:18:08 --> 00:18:11 asteroid belt. That's the region between Mars
00:18:11 --> 00:18:14 and Jupiter, but at the outer edge.
00:18:15 --> 00:18:18 Outer, edge of the main asteroid belt. Not
00:18:18 --> 00:18:20 sort of, not the kind of place you'd expect.
00:18:20 --> 00:18:23 You would think if the, if that rock had come
00:18:23 --> 00:18:25 from the asteroid belt, you'd think it would
00:18:25 --> 00:18:28 be near the inner edge. But the chemical
00:18:28 --> 00:18:30 specifics tell you that it's actually at the
00:18:30 --> 00:18:33 outer edge. and that is
00:18:34 --> 00:18:35 really very, very interesting
00:18:36 --> 00:18:38 deduction. Who would have thought that we
00:18:38 --> 00:18:41 will be able to pinpoint where that asteroid
00:18:41 --> 00:18:43 came from, ah, 66 million years after the
00:18:43 --> 00:18:46 event. and maybe the asteroid,
00:18:47 --> 00:18:48 I guess.
00:18:48 --> 00:18:49 Andrew Dunkley: They worked it out on the chemical
00:18:49 --> 00:18:51 composition elements rather than
00:18:51 --> 00:18:52 backtracking.
00:18:53 --> 00:18:55 Professor Fred Watson: Yes, that's right. we don't have enough
00:18:55 --> 00:18:57 information to backtrack. We don't know what
00:18:57 --> 00:19:00 angle it came in at or you know, what its
00:19:00 --> 00:19:03 orbit was before it collided with Earth. So
00:19:03 --> 00:19:05 it's all about chemistry is this. And in
00:19:05 --> 00:19:06 particular some quite
00:19:07 --> 00:19:09 sophisticated, well I suppose you call it
00:19:09 --> 00:19:11 chemical physics because they're using
00:19:11 --> 00:19:14 radiation techniques, basically to
00:19:15 --> 00:19:17 look for these levels of ruthenium,
00:19:19 --> 00:19:22 basically in the debris from the
00:19:22 --> 00:19:25 asteroid, crater and
00:19:25 --> 00:19:26 Surroundings. and,
00:19:27 --> 00:19:30 basically, looking at, how it
00:19:30 --> 00:19:33 compares with other, asteroid
00:19:33 --> 00:19:35 impacts and carbonaceous
00:19:35 --> 00:19:38 meteorites which also come from that
00:19:38 --> 00:19:40 region of the solar system.
00:19:41 --> 00:19:44 Andrew Dunkley: So what might have caused a rock from
00:19:44 --> 00:19:47 that particular part of the solar system to
00:19:48 --> 00:19:50 turn its attention to us? Did Saturn get
00:19:50 --> 00:19:52 upset and chuck a rock at us or something?
00:19:56 --> 00:19:59 Professor Fred Watson: it's probably, a
00:20:00 --> 00:20:02 just a gravitational disturbance, you know,
00:20:02 --> 00:20:05 something that disturbed
00:20:05 --> 00:20:08 the, orbit of this asteroid. in its
00:20:08 --> 00:20:11 comfortable zone of the asteroid belt may be
00:20:11 --> 00:20:14 an interaction with another asteroid. Because
00:20:14 --> 00:20:16 when objects come together, they needn't
00:20:16 --> 00:20:19 necessarily collide. But if they can interact
00:20:19 --> 00:20:21 with each other gravitationally so that one
00:20:21 --> 00:20:24 of them gets thrown out of its orbit
00:20:24 --> 00:20:26 and, you know, it's possible that that would
00:20:26 --> 00:20:27 have been the case.
00:20:28 --> 00:20:29 Andrew Dunkley: it's kind of like being in a crowd at a
00:20:29 --> 00:20:31 Chinese supermarket, really. That's.
00:20:32 --> 00:20:34 Professor Fred Watson: That's what it's like. Yes, yes.
00:20:34 --> 00:20:37 Andrew Dunkley: You didn't want to go that way, but you ended
00:20:37 --> 00:20:37 up.
00:20:38 --> 00:20:40 Professor Fred Watson: You have to. You have to go that way. Yeah.
00:20:40 --> 00:20:43 Just because everything's so crowded. It's
00:20:43 --> 00:20:46 a bit like that. The, the thing is
00:20:46 --> 00:20:49 that that event, whatever tipped it out of
00:20:49 --> 00:20:52 its comfortable orbit, that might have
00:20:52 --> 00:20:54 happened a long time before the 66 million
00:20:55 --> 00:20:57 year date ago,
00:20:58 --> 00:21:01 that we had for the impact for the extinction
00:21:01 --> 00:21:04 of the dinosaurs. So it might have been in an
00:21:04 --> 00:21:05 orbit that intersected the Earth's orbit for
00:21:05 --> 00:21:08 a long, long time, before the
00:21:08 --> 00:21:10 crunch finally came when it tried to be in
00:21:10 --> 00:21:12 the same place at the same time as the Earth.
00:21:12 --> 00:21:15 so. Yes, so there's details for this story
00:21:15 --> 00:21:18 that we still have a long way to finding
00:21:18 --> 00:21:21 out. but it may well have been, as
00:21:21 --> 00:21:22 I said, it's either a collision with another,
00:21:23 --> 00:21:26 asteroid. Or maybe even
00:21:26 --> 00:21:29 something like the gravitational pull of gas
00:21:29 --> 00:21:30 giants, maybe Jupiter,
00:21:31 --> 00:21:34 perturbed that object's orbit in such a
00:21:34 --> 00:21:36 way that it interacted with another asteroid
00:21:36 --> 00:21:39 and got thrown out of, thrown out of the
00:21:39 --> 00:21:41 asteroid belt. We probably will never know
00:21:41 --> 00:21:43 that. It's interesting enough, I think, to
00:21:43 --> 00:21:44 discover whereabouts it came from.
00:21:45 --> 00:21:47 Andrew Dunkley: Yes. The other thing that, came out of this
00:21:47 --> 00:21:50 is that it all but writes off
00:21:50 --> 00:21:52 that this was a comet impact.
00:21:52 --> 00:21:53 Professor Fred Watson: Yes.
00:21:53 --> 00:21:55 Andrew Dunkley: but not absolutely.
00:21:56 --> 00:21:58 Professor Fred Watson: Yeah, that's right. there's still a
00:21:58 --> 00:22:00 possibility, but, you know, comets are, a
00:22:00 --> 00:22:03 different beast from asteroids. They
00:22:03 --> 00:22:06 contain lots of ice, as well as the rock.
00:22:06 --> 00:22:09 And that means that the chemistry of
00:22:10 --> 00:22:13 the residual material from the impact would
00:22:13 --> 00:22:15 have different properties. so I think,
00:22:16 --> 00:22:18 it's, you know, you can never say never,
00:22:19 --> 00:22:21 but the Body of
00:22:21 --> 00:22:23 opinion seems to be that it was actually an
00:22:23 --> 00:22:25 asteroid rather than a comet.
00:22:25 --> 00:22:28 Andrew Dunkley: Yeah. I do have just one more question about
00:22:28 --> 00:22:30 this story and this is the most important one
00:22:30 --> 00:22:33 for it. Most important. You mentioned
00:22:33 --> 00:22:34 the element ruthenium.
00:22:36 --> 00:22:38 So was the person who discovered that named
00:22:38 --> 00:22:38 Ruth?
00:22:41 --> 00:22:43 Professor Fred Watson: that's a good question. I'd have to take that
00:22:43 --> 00:22:45 one unnoticed. But my guess is that that's
00:22:45 --> 00:22:46 where the name came from.
00:22:49 --> 00:22:51 Maybe it was somebody who was ruthless
00:22:52 --> 00:22:54 and they thought, yeah, I'll call it
00:22:54 --> 00:22:56 Ruthenian because I'm ruthless. Who knows
00:22:56 --> 00:22:57 that?
00:22:57 --> 00:22:59 Andrew Dunkley: Yeah, that's a thought too.
00:23:00 --> 00:23:02 that story, if you would like to read it, is
00:23:02 --> 00:23:05 available@spare.com.
00:23:06 --> 00:23:08 this is Space Nuts. Andrew Dunkley here with
00:23:08 --> 00:23:10 Professor Fred Watson.
00:23:14 --> 00:23:15 Professor Fred Watson: Space Nuts.
00:23:16 --> 00:23:19 Andrew Dunkley: now Fred, to the so called crisis in
00:23:19 --> 00:23:22 cosmology. We're talking about, the Hubble
00:23:22 --> 00:23:24 tension. Now we've done this story a few
00:23:24 --> 00:23:27 times over the years. This is where
00:23:27 --> 00:23:30 the, basically the expansion
00:23:30 --> 00:23:33 speed of the universe, depending on how you
00:23:33 --> 00:23:36 calculate, that number comes up with two
00:23:36 --> 00:23:38 different answers. And they have never been
00:23:38 --> 00:23:41 able to figure out why. But now
00:23:41 --> 00:23:42 they're starting to think, well, there's no
00:23:42 --> 00:23:44 crisis at all. Everything's right.
00:23:46 --> 00:23:48 Professor Fred Watson: yes. So,
00:23:51 --> 00:23:53 let me just explain how this tension, the
00:23:53 --> 00:23:56 Hubble tension comes about because
00:23:56 --> 00:23:58 there are two ways of
00:23:59 --> 00:24:02 measuring, the expansion of the
00:24:02 --> 00:24:05 universe. one uses
00:24:05 --> 00:24:08 standard candles and the other uses a
00:24:08 --> 00:24:10 standard ruler. And put it that way.
00:24:11 --> 00:24:13 So the standard candle's taking that first.
00:24:13 --> 00:24:16 if you know how bright your candle is, then
00:24:16 --> 00:24:18 you can work out how far away it is from you.
00:24:18 --> 00:24:21 because, you know, it's real
00:24:21 --> 00:24:23 brightness, it's intrinsic brightness. Then
00:24:23 --> 00:24:26 you can work out what is going on,
00:24:26 --> 00:24:29 in terms of. Because we know the way light
00:24:29 --> 00:24:32 gets fainter, we know the rule by which light
00:24:32 --> 00:24:34 gets fainter as you move to greater and
00:24:34 --> 00:24:35 greater distances. It's what we call the
00:24:35 --> 00:24:38 inverse square law. it goes as the square of
00:24:38 --> 00:24:40 the distance one over the square of the
00:24:40 --> 00:24:42 distance. So, standard candles are usually,
00:24:43 --> 00:24:46 stars in galaxies.
00:24:47 --> 00:24:50 and in fact this is what led us
00:24:50 --> 00:24:52 detect the expansion of the universe in the
00:24:52 --> 00:24:55 first place. Because, in the early years of
00:24:55 --> 00:24:57 the last century, around 1900,
00:24:58 --> 00:25:00 a group of astronomers, in the United
00:25:00 --> 00:25:03 States measured the intrinsic brightness of a
00:25:03 --> 00:25:05 particular kind of variable star, one whose
00:25:05 --> 00:25:07 brightness varies, but it varies in a
00:25:07 --> 00:25:10 periodic way. And it turns out that there's a
00:25:10 --> 00:25:13 relationship between how frequently it varies
00:25:13 --> 00:25:15 and what the intrinsic brightness is. And you
00:25:15 --> 00:25:17 usually take it at peak brightness or minimum
00:25:17 --> 00:25:19 brightness, whichever. It doesn't really
00:25:19 --> 00:25:22 matter as long as you know what it is. and so
00:25:22 --> 00:25:24 that's the time honored way of working out
00:25:24 --> 00:25:27 how far away galaxies are, to look for
00:25:27 --> 00:25:30 these variable stars and then
00:25:30 --> 00:25:33 basically look at, at you
00:25:33 --> 00:25:35 know, how bright they look to us. And from
00:25:35 --> 00:25:38 that work out the distance, and that lets you
00:25:38 --> 00:25:40 produce a value for what we call the Hubble
00:25:40 --> 00:25:43 constant, which is the number that
00:25:44 --> 00:25:46 basically tells you how fast the universe is
00:25:46 --> 00:25:49 expanding. the Hubble constant is
00:25:49 --> 00:25:51 in units of kilometers per second per
00:25:51 --> 00:25:54 megaparsec. But we don't really need to worry
00:25:54 --> 00:25:55 about that because at the moment all we're
00:25:55 --> 00:25:58 interested in is the number. And so until
00:25:58 --> 00:26:01 now, the best estimates, from the
00:26:01 --> 00:26:03 standard candles, in other words, the Cepheid
00:26:03 --> 00:26:06 variables have come, out at
00:26:07 --> 00:26:09 about 74 kilometers per second per
00:26:09 --> 00:26:12 megaparsec. But then the standard ruler
00:26:12 --> 00:26:14 method is looking back at the flash of the
00:26:14 --> 00:26:16 Big Bang, the cosmic microwave background
00:26:16 --> 00:26:19 radiation, which we see, as it was about 13
00:26:19 --> 00:26:22 billion years ago. And there are features in
00:26:22 --> 00:26:25 that variation which have
00:26:25 --> 00:26:27 separations that we know would be
00:26:27 --> 00:26:29 characteristic of a certain
00:26:30 --> 00:26:32 particular time. And what we're talking about
00:26:32 --> 00:26:35 here, when I say features, I mean peaks and
00:26:35 --> 00:26:37 troughs in the temperature of the Big Bang,
00:26:37 --> 00:26:40 effectively what you're looking at. and from
00:26:40 --> 00:26:42 that you can also deduce the Hubble constant,
00:26:42 --> 00:26:45 the expansion rate as it is today. but
00:26:45 --> 00:26:48 the answer you get from that is 67.5
00:26:48 --> 00:26:51 kilometers per second per megaparsec. Yeah.
00:26:51 --> 00:26:54 Which is round about six and a half
00:26:54 --> 00:26:56 kilometers per second per megaparsec,
00:26:56 --> 00:26:58 different from the other one that is now
00:26:58 --> 00:27:01 we're in such a precise era that now
00:27:01 --> 00:27:04 has people worried. so what's
00:27:04 --> 00:27:06 happened? Well, the same team
00:27:06 --> 00:27:09 who've done a huge amount of this work in the
00:27:09 --> 00:27:11 past, led by, Dr. Wendy Freeman
00:27:11 --> 00:27:14 Friedman, one of the big names in this kind
00:27:14 --> 00:27:17 of science in the United States. Wendy
00:27:17 --> 00:27:20 and her team have used our
00:27:20 --> 00:27:22 new toy, the James
00:27:22 --> 00:27:24 Webb Space Telescope.
00:27:24 --> 00:27:27 Andrew Dunkley: we always knew it would solve this problem.
00:27:28 --> 00:27:30 Professor Fred Watson: We knew it would certainly help. It would
00:27:30 --> 00:27:31 either make it worse or it would solve it.
00:27:31 --> 00:27:33 And yeah, you're right. To cut to the chase,
00:27:33 --> 00:27:35 it's probably solved it because it's now
00:27:35 --> 00:27:38 looking as though the
00:27:38 --> 00:27:41 method, is more like that. You know, the
00:27:41 --> 00:27:43 method where you measure the brightness of
00:27:43 --> 00:27:45 these variable stars is giving an answer more
00:27:45 --> 00:27:48 like 70km per second per megaparsec,
00:27:48 --> 00:27:51 which is much closer to that 67.5 that you
00:27:51 --> 00:27:52 get from the cosmic microwave background
00:27:52 --> 00:27:55 radiation. And it turns out that when you
00:27:55 --> 00:27:58 think about the error, potential
00:27:58 --> 00:28:00 error of both of them, then it overlaps.
00:28:00 --> 00:28:03 So in that regard, you've got something that
00:28:03 --> 00:28:05 falls within the error bounds of both of
00:28:05 --> 00:28:07 these methods. And so maybe we are seeing the
00:28:07 --> 00:28:08 right answer at last.
00:28:09 --> 00:28:11 Andrew Dunkley: So it basically brings it back to an average.
00:28:12 --> 00:28:15 Professor Fred Watson: That's right. That's right. Yes.
00:28:15 --> 00:28:18 You know, when I started my career, Andrew,
00:28:19 --> 00:28:21 there were two camps. and
00:28:22 --> 00:28:24 basically they were using similar methods.
00:28:24 --> 00:28:27 one said that the Hubble, constant was
00:28:27 --> 00:28:29 50 kilometers per second per megaparsec. The
00:28:29 --> 00:28:31 other said it was 100 kilometers per second
00:28:31 --> 00:28:33 per megapar a second. They were both right.
00:28:34 --> 00:28:35 they thought they were both right. And, it
00:28:35 --> 00:28:37 turned out that the answer, the real answer
00:28:37 --> 00:28:40 was the average of them. It was 70 or 75 or
00:28:40 --> 00:28:41 thereabouts.
00:28:41 --> 00:28:44 Andrew Dunkley: There you go. pretty simple solution at the
00:28:44 --> 00:28:47 end of the day, but a lot of hard work went
00:28:47 --> 00:28:48 into finding it.
00:28:49 --> 00:28:51 Professor Fred Watson: Yeah, we hope that resolves the Hubble
00:28:51 --> 00:28:53 tension. It will be great. Hopefully cosmic
00:28:53 --> 00:28:55 crisis disappeared. Yeah, Yeah.
00:28:55 --> 00:28:57 Andrew Dunkley: I wouldn't be surprised, though, in months to
00:28:57 --> 00:28:59 come, somebody comes up with a debunking
00:28:59 --> 00:29:00 theory.
00:29:01 --> 00:29:02 Professor Fred Watson: well, there you go.
00:29:02 --> 00:29:03 Andrew Dunkley: It could happen.
00:29:03 --> 00:29:03 Professor Fred Watson: It could happen.
00:29:04 --> 00:29:07 Andrew Dunkley: at this point in time, looks like it might
00:29:07 --> 00:29:10 have been resolved. This has been frustrating
00:29:10 --> 00:29:12 for a long time, but, maybe as simple as. Oh,
00:29:12 --> 00:29:15 hang on a sec. You're both right, and here's
00:29:15 --> 00:29:17 why. Yeah, yeah, yeah. that.
00:29:17 --> 00:29:18 Stories on
00:29:18 --> 00:29:21 scitechdaily.com? without
00:29:21 --> 00:29:23 notice. Fred, that's come through from one of
00:29:23 --> 00:29:25 our live viewers, Wayne. Hi, Wayne.
00:29:25 --> 00:29:28 this harks back to the snowball,
00:29:28 --> 00:29:31 Earth story we did. Wayne asks, I wonder
00:29:31 --> 00:29:33 how much bigger the diameter of a frozen
00:29:33 --> 00:29:36 Earth would be to the current Earth. Do we
00:29:36 --> 00:29:38 have any idea what that might have been?
00:29:38 --> 00:29:41 Professor Fred Watson: Yeah, it probably wasn't that much different.
00:29:41 --> 00:29:44 it, you know, I mean, at the moment,
00:29:45 --> 00:29:47 a lot of that water's still there, but it's
00:29:47 --> 00:29:50 wet and, you know, and this
00:29:50 --> 00:29:52 is. Now it's, it's turned into ice. So,
00:29:53 --> 00:29:55 it's not going to be. It's certainly not
00:29:55 --> 00:29:57 going to be, tens of kilometers different.
00:29:58 --> 00:30:01 it might be a few kilometers different, on
00:30:01 --> 00:30:02 average. And I'm talking about the average.
00:30:03 --> 00:30:05 but, but I don't think it would, you know, it
00:30:05 --> 00:30:06 wouldn't have turned into a gas giant or
00:30:06 --> 00:30:08 anything like that. That's an interesting
00:30:08 --> 00:30:10 question, though, because we think it's
00:30:10 --> 00:30:12 because of frozen water out, in the depths of
00:30:12 --> 00:30:15 the solar system, adding to the mass of the
00:30:15 --> 00:30:17 gas giants as they were being formed. We
00:30:17 --> 00:30:20 think that is one reason why they became so
00:30:20 --> 00:30:22 big because they had enough mass to hold onto
00:30:23 --> 00:30:25 a gas envelope. and so it's a
00:30:25 --> 00:30:28 good question to ask that, ah, what
00:30:28 --> 00:30:30 difference would the ice make? But this is
00:30:30 --> 00:30:32 really just a surface layer of ice rather
00:30:32 --> 00:30:35 than a solid block of ice which may be at the
00:30:35 --> 00:30:37 core of the gas giants.
00:30:37 --> 00:30:40 Andrew Dunkley: Indeed. All right, thank you, Wayne. Nice to
00:30:40 --> 00:30:42 get questions without notice while we're
00:30:42 --> 00:30:44 going out live during our recording sessions.
00:30:44 --> 00:30:46 Good to hear from you, Fred. We're just about
00:30:46 --> 00:30:47 done. Thank you very much.
00:30:48 --> 00:30:50 Professor Fred Watson: A, ah, pleasure, Andrew. Good to talk and,
00:30:50 --> 00:30:52 some interesting topics. And there'll be more
00:30:52 --> 00:30:52 next week.
00:30:53 --> 00:30:55 Andrew Dunkley: Indeed there will. Thanks, Fred. Professor
00:30:55 --> 00:30:57 Fred Watson, astronomer at large. Don't
00:30:57 --> 00:30:59 forget to check us out online
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00:31:06 --> 00:31:08 interested. just, have a bit of a flick
00:31:08 --> 00:31:10 around. And if you follow us on social media,
00:31:10 --> 00:31:13 don't forget to like us, follow us, add us to
00:31:13 --> 00:31:15 your favorites list, or click the subscribe
00:31:15 --> 00:31:18 button, depending on which platform it is.
00:31:18 --> 00:31:21 and thanks, to Huw in the studio, as always,
00:31:21 --> 00:31:23 and from me, Andrew Dunkley. We will see you
00:31:23 --> 00:31:26 again soon on the very next episode of
00:31:26 --> 00:31:28 SpaceNuts. Bye bye.
00:31:29 --> 00:31:31 You've been listening to the Space Nuts
00:31:31 --> 00:31:34 podcast, available at
00:31:34 --> 00:31:36 Apple Podcasts, Spotify,
00:31:36 --> 00:31:39 iHeartRadio or your favorite podcast
00:31:39 --> 00:31:40 player. You can also stream on
00:31:40 --> 00:31:43 demand@bytes.com this.
00:31:43 --> 00:31:45 Professor Fred Watson: Has been another quality podcast production
00:31:45 --> 00:31:47 from bytes.com.