How One Dinosaur-Killing Impact May Have Triggered Global Firestorms

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Andrew Dunkley: Hello again and thank you for joining us on

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another episode of Space Nuts. My name is

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Andrew Dunkley, your host. It's great to have

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your company. I hope you're well and I hope

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you can stick around. We've got some really

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great storeys today. These are fascinating.

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Remember that asteroid impact that led to the

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loss of the dinosaurs, you know, happened a

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couple of weeks ago? Uh, well, uh, it

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may have been much worse than we first

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thought. Lost lots of, uh, crispy critters as

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a consequence. We'll explain all that. Uh,

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there was a near Earth asteroid discovered

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around 30 years ago. 30 years ago. Well, now

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new evidence suggests it may

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have been a comet. And I love

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this storey. This is about a Canadian amateur

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astronomer who was planning a trip online

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using, uh, using online maps. And

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he made a massive discovery. We'll tell you

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all about it on this episode of space nuts.

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Generic: 15 seconds. Guidance is internal.

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10, 9. Ignition

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sequence start.

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Jonti Horner: Space nuts.

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Generic: 5, 4, 2, 1, 2, 3, 4,

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Jonti Horner: 5, 5, 4, 3, 2, 1. Space

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nuts.

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Generic: Astronauts report it feels good.

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Andrew Dunkley: And joining us, uh, this time around

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with Fred Watson, gallivanting around chasing

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solar eclipses is Professor Jonty

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Horner, professor of Astrophysics at the

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University of Southern Queensland. Welcome

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back, Jonty.

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Jonti Horner: Oh, uh, thanks for having me. It's good to be

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the substitute Yorkshireman again.

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Andrew Dunkley: Yes, we've got a whole set of them.

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It's really good stuff.

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Um, now we've got some amazing

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storeys. I know you've been a very busy young

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fellow for, um. Well, since we last

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spoke to you, uh, you do your own sort of

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gallivanting, but we managed to nail you down

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for a couple of weeks, which is fantastic.

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Uh, let's get straight into it because, um,

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these storeys dovetail. Well, we've got an

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asteroid that

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may have been a comet. Then we've got an

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asteroid that hit Earth that seems, uh, to

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have done more damage than we thought. And

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then we've got a hole in the ground

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discovered while someone was planning a

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holiday. All kind of related.

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So let's get stuck into the, uh, first

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storey. A near Earth asteroid that

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was discovered 30 years ago they think might

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have been a comet.

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Jonti Horner: Yeah, this is a lovely storey and it ties

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into something that we've talked about in

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different lights previously when I've been on

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the show, and I'm sure Fred Watson spoken

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about it quite frequently as well, which is

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that, uh, very human need to break things up

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into manageable chunks, you know, so you

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go from being a child to being a teenager to

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being an adult and there's A miraculous day

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when you wake up and you're suddenly legally

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able to drive.

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Andrew Dunkley: Yes.

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Jonti Horner: And in different countries, that's a

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different debt. But we all have it. But

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fundamentally, you're not really any

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different as a person the day before that and

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the day after it. What we're doing is we're

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breaking up this kind of continuum of human

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experience into chunks, where we group things

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that are similar together and we put things

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that are more different into separate groups.

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And I've talked about this in the past when

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we've talked about the difference between

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planets and stars and that amazing middle

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ground that are brown dwarfs, where in

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effect, you've actually got objects of all

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sizes from the size of a grain of sand,

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actually from the size of a single atom or a

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single subatomic particle, all the way up to

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the biggest galaxies and beyond in this kind

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of continuum of sizes. But you go through

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kind of rock to planet to brown dwarf to

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star. And we put these arbitrary divisions in

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so that we can group things that look similar

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together and study them to make life easier.

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And we talked about that, of course, in the

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context of Pluto, with the whole thing of

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when is a planet not a planet, when it's a

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dwarf planet, and why all that happened.

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That's exactly the same kind of thing. In my

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kind of contextualization, that was the right

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decision. That's a hill I'll quite happily

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plant my flag on. But

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Pluto's like the gangly teenager. From a

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distance, it looks big and like a serious

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adult, but it's still not very good at

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tidying its room up. That's the kind of

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analogy you there. This

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whole storey is another one of those same

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things. If we had been talking

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300 years ago, people would have been

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familiar with comets, at least the bright

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ones. You know, things that get bright enough

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to see with the naked eye that have a glowy

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coma and a tail. They appear briefly, then

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vanish forever. And we had great comets a

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couple of times in the last few years, on

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average one per decade. But it's a bit hit

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and miss. And the idea is, with modern

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scientific knowledge, what you're seeing when

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you get that phenomenon is a big dirty

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snowball or a snowy dirt ball that's whizzing

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around the sun on this hugely elongated

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orbit. When it's far from the sun and it's

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nice and cold, we just don't see it. You'd

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need the biggest telescopes on the world

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because you've just got this little thing

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reflecting a bit of sunlight. But when it

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comes near to the sun, its surface gets hot.

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The volatile material on it gets too hot to

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still be solid, so turns into gas. And

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that gas erupts from the surface, carrying

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with it dust, shrouds that snowball

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in what's called a coma, a big spherical

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cloud of gas. And then the solar wind pushes

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the gas and dust away from the sun and you

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get the tails. And so a comet, as we see

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it, is pretty big, can be millions or

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tens of kilometres, tens of millions of

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kilometres across, which is this huge amount

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of gas and dust floating around in the solar

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system, all given off by an icy,

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rocky, rubbly object only a few kilometres

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across in the head. And that's a comet. So

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it's basically something that has activity

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that out gases as it goes around the sun.

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Andrew Dunkley: Yep.

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Jonti Horner: 19. In 1801, sorry came along

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and Giuseppe Piazzi found Ceres, which

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was an object between the orbits of Mars and

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Jupiter. And he found it because they were

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looking for a planet, because people had

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suggested that might just be that there's a

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planet between Mars and Jupiter. So the

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celestial police were looking, but Piazzi got

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there first and that was the first of the

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asteroids. And over the decades, and

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the couple of centuries that followed, one

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object became four, became tens,

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became hundreds, became thousands, and

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nowadays it's over a million. And if we

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were talking kind of 30 or 40 years ago, we'd

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have had a very clear idea of what an

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asteroid is and that an asteroid is very

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different to a comet. So an asteroid is a

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rocky or metallic object that

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even when it gets near the sun, just stays as

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a rocky metallic object. No gas comes off it,

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just a lump of rock or rubble going around

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the sun. So

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rocky, rubbly object, icy object with loads

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of gas. You've got a comet, you've got an

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asteroid, very distinct.

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Now, water's got a bit more muddied for

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a few reasons over the last few decades.

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Firstly, you had objects called the

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Centaurs, which I studied for my PhD, that

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are big icy objects that are too far away

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from the sun most of the time to outgas. So

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got kind of asteroidal classifications and a

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couple of them got a bit nearer in and

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started out gassing, so got a dual classific.

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Chiron is the most famous. Chiron has both an

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asteroidal classification and, um, a cometary

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classification. Cause sometimes it looks like

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an asteroid, sometimes it looks like a comet.

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You then have things like the Geminid meteor

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shower every December, which is our best

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meteor shower. I love it dearly. Almost

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all of the meteor showers are produced by

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comets and we get them when we go through the

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dust that has been left behind by the

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activity of the comet when it was out

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gassing. But when they found the parent of

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the Geminids, it doesn't look like a comet,

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it's an asteroid. So the idea became that

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maybe it's a rock comet and it's getting so

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close to the sun it's shedding dust and we

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get the meteor shower. Then there were

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a couple of comets that were lost. And then

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many, many decades later, an asteroid was

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found that looked to be moving on the same

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orbit as a comet. And so maybe they're the

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same object and the comet has turned off. And

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when the comet has turned off and stopped

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making any gas, maybe it looks like an

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asteroid. So there's this blurring going on.

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In reality, what you've got is a

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continuum from rocky and metallic and nothing

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else on one end to incredibly icy on the

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other, and everything in between where you

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have more rock, less ice, more ice, less rock

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blurring together. That's a

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hell of a lengthy introduction, hell of a lot

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of background to give the context for this

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storey. So, in light of all that, back in

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1998 there was this near Earth

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asteroid discovered. It goes by the of 1998

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SH2 and it looks like a lump of rock.

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It goes around the sun every four or five

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years, whizzing around. It's been seen at a

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few apparitions since. And, um, that's all

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well and good. We know a few thousand Near

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Earth asteroids now and we're finding more

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and more of them all the time. And people are

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particularly interested because, of course,

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if they come near the Earth, there's a

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possibility that eventually one of them will

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come too near the Earth and will hit us and

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we'll have issues. And ask the dinosaurs

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about that. We can come back to that a little

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bit later on. So there's a lot of interest in

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learning more about near Earth asteroids and

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following them because the longer you observe

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them, the more accurately you know how

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they're moving. So the better you can predict

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into the future where they'll be and

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therefore rule out the chance of that object

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hitting the Earth. Uh, may also, of course,

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be interesting to people who want to mine

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that object in the future with off Earth

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mining that if you want to go mine it, you

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need to know where it is. Yeah, so

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that's this object. Brilliant. We found an

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Earth asteroid.

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Where it gets interesting for this storey

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is that, uh, back in August 2025,

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which is what, 27 years after this thing was

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discovered it had another close approach

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to Earth. Now, this wasn't like the

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forthcoming approach for the asteroid

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Apophis, which is going to come closer to us

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than geostationary satellites. This was close

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to astronomers and distant to everybody else.

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You're talking about the thing coming about 3

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million kilometres away at its closest

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approach. Now, that's relatively close, but

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it's not something to get particularly

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panicked about. That's nearly 10 times as far

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away as the moon is, about 8 times as far

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away as the Moon is. But it's near enough

259
00:10:00.330 --> 00:10:01.810
that if you want to learn more about the

260
00:10:01.810 --> 00:10:03.530
asteroid, what you can do is you can get the

261
00:10:03.530 --> 00:10:06.410
planetary radar, uh, that they used to beam

262
00:10:06.410 --> 00:10:08.370
radar, uh, out into space and bounce it off

263
00:10:08.370 --> 00:10:10.850
things and get it back. Yeah, to try and

264
00:10:10.850 --> 00:10:13.130
bounce radar, uh, off this asteroid

265
00:10:13.710 --> 00:10:15.750
to get an image of what its shape is, to

266
00:10:15.750 --> 00:10:17.670
learn about its rotation and figure out how

267
00:10:17.670 --> 00:10:20.350
big it is. Because even with the biggest

268
00:10:20.350 --> 00:10:23.030
telescopes on the planet, something like this

269
00:10:23.030 --> 00:10:26.030
is always just a single pixel. You can't zoom

270
00:10:26.030 --> 00:10:28.870
in. So what they did was they got the

271
00:10:28.870 --> 00:10:31.270
planetary radar, uh, sent radar out to this

272
00:10:31.270 --> 00:10:32.350
object and missed

273
00:10:34.350 --> 00:10:37.150
a little bit. Embarrassing as you do, it

274
00:10:37.150 --> 00:10:39.470
wasn't quite where it was supposed to be.

275
00:10:40.340 --> 00:10:41.700
So based on all those historical

276
00:10:41.700 --> 00:10:44.020
observations, you can predict into the future

277
00:10:44.820 --> 00:10:47.820
where the asteroid will be based purely on

278
00:10:47.820 --> 00:10:49.460
the gravity of all the planets. It's getting

279
00:10:49.460 --> 00:10:51.500
pulled around by the Earth, uh, and Venus,

280
00:10:51.500 --> 00:10:53.620
Jupiter, everything's pulling and tugging on

281
00:10:53.620 --> 00:10:56.060
it. And you can in a very prescriptive way

282
00:10:56.060 --> 00:10:57.900
run its orbit forward in time and say where

283
00:10:57.900 --> 00:11:00.660
it will be in the future if the only thing

284
00:11:00.820 --> 00:11:02.740
acting on it is gravity.

285
00:11:03.700 --> 00:11:06.420
But it wasn't where it should be. Uh, the

286
00:11:06.420 --> 00:11:08.700
fact it wasn't where it should be says

287
00:11:08.700 --> 00:11:10.340
something else is happening as well.

288
00:11:10.340 --> 00:11:12.300
Something else is happening to push it around

289
00:11:12.540 --> 00:11:14.980
now. So at this point, sometimes that we get

290
00:11:14.980 --> 00:11:17.100
the, oh, well, it must be an alien spaceship

291
00:11:17.100 --> 00:11:19.980
thing happening. That's exactly what's

292
00:11:19.980 --> 00:11:21.540
happened in the past with people suggesting

293
00:11:21.540 --> 00:11:24.340
there's maybe something more going on that

294
00:11:24.340 --> 00:11:26.060
actually hasn't happened with this one, which

295
00:11:26.060 --> 00:11:28.380
is really nice to see. But what

296
00:11:28.940 --> 00:11:31.660
that being out of position tells you is that

297
00:11:31.660 --> 00:11:33.860
there are non gravitational forces acting on

298
00:11:33.860 --> 00:11:36.500
this thing. Something other than gravity is

299
00:11:36.500 --> 00:11:38.440
happening to push it around a little bit.

300
00:11:39.000 --> 00:11:41.200
Now, M. If we rewind to comets for a little

301
00:11:41.200 --> 00:11:43.640
bit. I remember when I was a teenager back in

302
00:11:43.640 --> 00:11:46.160
the early 1990s, we had Comet Swift Tuttle

303
00:11:46.160 --> 00:11:48.520
came past and, um, Comet Swift Tuttle's a

304
00:11:48.520 --> 00:11:51.040
parent of the Perseid shower. And, um, that

305
00:11:51.040 --> 00:11:52.600
was kind of a relief because at, uh, Its

306
00:11:52.600 --> 00:11:54.720
previous apparition, Comet Swift Tuttle, had

307
00:11:54.720 --> 00:11:57.720
been seen widely observed and had been

308
00:11:57.880 --> 00:11:59.320
predicted that it would come back in about

309
00:11:59.320 --> 00:12:01.400
120 years. It would come back in the early

310
00:12:01.400 --> 00:12:03.880
1980s and it didn't show up.

311
00:12:04.420 --> 00:12:06.240
M which was a bit weird because this is a

312
00:12:06.240 --> 00:12:08.160
bigger and more active comet than Comet

313
00:12:08.160 --> 00:12:10.280
Hallie. It's probably the biggest of the

314
00:12:10.280 --> 00:12:12.280
comets with a period less than 200 years.

315
00:12:12.360 --> 00:12:15.280
Pretty epic object. And it came back 10

316
00:12:15.280 --> 00:12:17.000
years later. Now, by the time it came back,

317
00:12:17.000 --> 00:12:18.720
people had figured out kind of what was going

318
00:12:18.720 --> 00:12:21.280
on, had realised that it was going to be

319
00:12:21.280 --> 00:12:23.560
late. But part of the complexity there

320
00:12:24.280 --> 00:12:25.920
was that, uh, because this is quite an active

321
00:12:25.920 --> 00:12:28.560
comet, when it's ejecting gas and dust to

322
00:12:28.560 --> 00:12:31.280
space, that process acts like a

323
00:12:31.280 --> 00:12:33.900
rocket engine that pushes it around. So it's

324
00:12:33.900 --> 00:12:36.140
ejecting gas in one direction and that exerts

325
00:12:36.140 --> 00:12:37.940
a force pushing the nucleus in another.

326
00:12:38.980 --> 00:12:41.980
And that is not a predictable thing in

327
00:12:41.980 --> 00:12:44.500
that every time a comet comes around the sun,

328
00:12:44.660 --> 00:12:46.660
its rotation will be a bit different. Some

329
00:12:46.660 --> 00:12:48.580
active areas will turn off and some will turn

330
00:12:48.580 --> 00:12:51.420
on. So while you can get a general trend and

331
00:12:51.420 --> 00:12:53.340
you can make loose predictions, there's

332
00:12:53.340 --> 00:12:55.500
always going to be a bit of uncertainty in

333
00:12:55.500 --> 00:12:57.340
where a comet will be in the future because

334
00:12:57.340 --> 00:12:59.420
it's got these forces pushing and nudging it

335
00:12:59.420 --> 00:13:02.340
around. You know, it's a bit like, I don't

336
00:13:02.340 --> 00:13:04.320
know if you could strap a few fireworks to a

337
00:13:04.320 --> 00:13:05.760
snowball and throw it up in the air. That's

338
00:13:05.760 --> 00:13:07.480
probably not very healthy to do. But you get

339
00:13:07.480 --> 00:13:08.880
the same kind of thing, they go off at

340
00:13:08.880 --> 00:13:11.120
different times and be pushed around all over

341
00:13:11.120 --> 00:13:13.840
the place. Um, interestingly, Comet Encke,

342
00:13:13.840 --> 00:13:15.480
which is a comet with the shortest non

343
00:13:15.480 --> 00:13:18.200
orbital period, has been seen every three and

344
00:13:18.200 --> 00:13:20.640
a half years, 3.3 years for more than 200

345
00:13:20.640 --> 00:13:22.880
years. And we've actually seen its orbital

346
00:13:22.880 --> 00:13:24.800
period get shorter and then get longer again

347
00:13:24.960 --> 00:13:26.800
as a direct result of the jets on its

348
00:13:26.800 --> 00:13:29.400
surface, uh, pushing it around and those jets

349
00:13:29.400 --> 00:13:31.680
changing the rotation direction of the

350
00:13:32.050 --> 00:13:34.850
comet. Loads of cool stuff there.

351
00:13:36.130 --> 00:13:39.090
So with that knowledge, you can look at this

352
00:13:39.090 --> 00:13:41.410
object, 1998 SH2.

353
00:13:41.890 --> 00:13:44.250
It's not where it's supposed to be. So that

354
00:13:44.250 --> 00:13:45.690
suggests that there's non gravitational

355
00:13:45.690 --> 00:13:48.050
forces happening. But whenever people have

356
00:13:48.050 --> 00:13:50.280
observed it in the past, it has looked inert.

357
00:13:50.280 --> 00:13:52.770
Uh, it's looked like an asteroid.

358
00:13:53.650 --> 00:13:56.490
What that suggests is that it is active.

359
00:13:56.490 --> 00:13:58.410
It's got some outgassing happening, but at

360
00:13:58.410 --> 00:14:01.250
such low levels that it wasn't possible to

361
00:14:01.250 --> 00:14:04.180
detect them before. So that was a clue

362
00:14:04.660 --> 00:14:06.340
that seems a really likely storey.

363
00:14:06.500 --> 00:14:08.940
So scientists go away and they do a couple of

364
00:14:08.940 --> 00:14:11.660
things. Firstly, they look for pre discovery

365
00:14:11.660 --> 00:14:13.900
observations of this, you know, times when

366
00:14:13.900 --> 00:14:16.060
there was a photographic plate made 50 years

367
00:14:16.060 --> 00:14:17.820
ago that just happened to have the object in

368
00:14:17.820 --> 00:14:20.220
the field of view so you can get a longer

369
00:14:20.220 --> 00:14:22.020
period of knowledge of how it's moved.

370
00:14:22.100 --> 00:14:22.580
Andrew Dunkley: Yeah.

371
00:14:23.380 --> 00:14:25.140
Jonti Horner: And um, with these really accurate

372
00:14:25.140 --> 00:14:27.980
observations, you can tell that it has been

373
00:14:27.980 --> 00:14:29.540
misbehaving for a long time. It's getting

374
00:14:29.540 --> 00:14:32.300
pushed and nudged around. What then

375
00:14:32.300 --> 00:14:34.380
happened was they used some of the really

376
00:14:34.380 --> 00:14:36.860
biggest telescopes in the world to take a

377
00:14:36.860 --> 00:14:39.580
look at it and detect just a tiny hint of gas

378
00:14:39.580 --> 00:14:42.060
being emitted, tiny little wisp.

379
00:14:42.380 --> 00:14:44.780
And so you put all that together and um, this

380
00:14:44.780 --> 00:14:46.980
thing is probably, of all the comets we know

381
00:14:46.980 --> 00:14:49.380
in the solar system, the least active that we

382
00:14:49.380 --> 00:14:51.740
currently know of. But it is exhibiting

383
00:14:51.740 --> 00:14:54.220
cometary behaviour. So it's another object

384
00:14:54.220 --> 00:14:56.900
really straddling the boundary. And it's

385
00:14:56.900 --> 00:14:58.860
fascinating. It'll be wonderful to learn more

386
00:14:58.860 --> 00:15:01.600
about it. But it's fascinating too,

387
00:15:02.160 --> 00:15:04.280
because here's the thing that looks like an

388
00:15:04.280 --> 00:15:06.160
asteroid, sounds like an asteroid. It does

389
00:15:06.160 --> 00:15:07.920
everything you'd expect an asteroid to do,

390
00:15:08.320 --> 00:15:10.480
except it's wibbling and misbehaving a bit.

391
00:15:10.480 --> 00:15:13.080
Now, if you're finding hundreds and thousands

392
00:15:13.080 --> 00:15:14.960
of near Earth asteroids and you want to know

393
00:15:14.960 --> 00:15:17.960
whether the Earth's safe, well, if you see

394
00:15:17.960 --> 00:15:19.720
something that's an asteroid, you can predict

395
00:15:19.720 --> 00:15:22.280
where it is with gravity going forward, the

396
00:15:22.280 --> 00:15:24.800
Earth's safe. What this is telling you is

397
00:15:24.800 --> 00:15:27.200
that, uh, gravity may not be enough. So you

398
00:15:27.200 --> 00:15:28.840
can't just say, well, it looks like it'll be

399
00:15:28.840 --> 00:15:31.000
safe, we'll stop looking. Because if this

400
00:15:31.000 --> 00:15:33.400
object's unpredictable, what about all the

401
00:15:33.400 --> 00:15:34.680
other ones we're finding too?

402
00:15:34.760 --> 00:15:36.880
Andrew Dunkley: I was about to bring that up. There's got to

403
00:15:36.880 --> 00:15:37.720
be more than one.

404
00:15:38.280 --> 00:15:40.760
Jonti Horner: Oh, absolutely. Um, we found

405
00:15:41.320 --> 00:15:43.400
quite a few of these over the years now in

406
00:15:43.400 --> 00:15:45.480
various circumstances. My favourite

407
00:15:46.280 --> 00:15:48.680
really is the Taurid stream of debris. We get

408
00:15:48.680 --> 00:15:50.400
the Taurid meteor shower every year from

409
00:15:50.400 --> 00:15:52.320
about September to December. We've got the

410
00:15:52.320 --> 00:15:54.920
northern and southern Taurids. We also get a

411
00:15:54.920 --> 00:15:57.000
daytime meteor shower in June called the Beta

412
00:15:57.000 --> 00:15:59.630
Taurids. Result is we spend about

413
00:15:59.710 --> 00:16:02.510
four months of every 12 passing

414
00:16:02.510 --> 00:16:05.230
through this enormous broad swath of debris

415
00:16:05.630 --> 00:16:07.630
where on any given night, when the meteor

416
00:16:07.630 --> 00:16:09.510
shower is active even at its peak ulcely,

417
00:16:09.510 --> 00:16:12.190
four or five meteors an hour, the debris is

418
00:16:12.190 --> 00:16:14.830
very spread out. But because the Earth spends

419
00:16:14.830 --> 00:16:16.750
so long going through it, we get more debris

420
00:16:16.750 --> 00:16:18.630
from that stream than all other meteor

421
00:16:18.630 --> 00:16:21.070
showers combined over the course of a year.

422
00:16:22.190 --> 00:16:25.070
At the core of that is Comet Encke, which is

423
00:16:25.070 --> 00:16:27.950
that comet with a 3.3 year period, but

424
00:16:27.950 --> 00:16:30.370
also a huge amount of other rubble and

425
00:16:30.370 --> 00:16:33.370
debris. There's lots and lots of asteroids or

426
00:16:33.370 --> 00:16:35.130
things that behave like asteroids moving

427
00:16:35.130 --> 00:16:37.770
around in the storage stream. And the idea is

428
00:16:37.770 --> 00:16:40.410
that this was a, uh, mega comet 20 or

429
00:16:40.410 --> 00:16:43.290
30,000 years ago that fell apart,

430
00:16:43.770 --> 00:16:46.249
giving us this stream of debris. Comet Encke

431
00:16:46.650 --> 00:16:48.930
was probably behaving like an asteroid if

432
00:16:48.930 --> 00:16:50.650
he'd found it a thousand years ago. But

433
00:16:50.650 --> 00:16:53.330
something happened 250 years ago to wake it

434
00:16:53.330 --> 00:16:55.850
up and it started behaving like a comet and

435
00:16:55.850 --> 00:16:58.430
we see it as a comet. And the other asteroids

436
00:16:58.590 --> 00:17:01.430
in that stream are currently dormant and

437
00:17:01.430 --> 00:17:03.750
there's a load of them. So it's likely in the

438
00:17:03.750 --> 00:17:06.070
inner solar system that even just in the

439
00:17:06.070 --> 00:17:08.150
Taurid Stream, you're going to have hundreds,

440
00:17:08.150 --> 00:17:10.790
if not thousands of objects just like

441
00:17:10.790 --> 00:17:13.750
1998 SH2 that straddle

442
00:17:13.750 --> 00:17:15.390
that boundary between the comet and the

443
00:17:15.390 --> 00:17:16.030
asteroid.

444
00:17:18.190 --> 00:17:20.510
Andrew Dunkley: Fair enough. And, uh, as a consequence of

445
00:17:20.510 --> 00:17:21.790
that, they've had to rename it.

446
00:17:23.880 --> 00:17:26.520
Jonti Horner: Yep. So it now has a cometary classification

447
00:17:26.520 --> 00:17:29.400
as well. What happens with comets is you

448
00:17:29.400 --> 00:17:32.120
get. When people find a comet,

449
00:17:32.570 --> 00:17:35.570
um, it's C, slash, then the year,

450
00:17:35.570 --> 00:17:37.400
ah, and then a catalogue number. So basically

451
00:17:37.400 --> 00:17:39.680
every comet gets a unique identifier. So we

452
00:17:39.680 --> 00:17:42.040
remember Chuchinshan Atlas, which,

453
00:17:42.570 --> 00:17:45.040
um. I'm trying to remember the correct ID for

454
00:17:45.040 --> 00:17:47.581
it, but it was, I think it was like 2023

455
00:17:47.719 --> 00:17:50.560
A, ah, 1 or something like that, A3. So

456
00:17:50.560 --> 00:17:52.520
the A means that it's discovered in the first

457
00:17:52.520 --> 00:17:54.900
fortnight of the year. 3 is the third object

458
00:17:54.900 --> 00:17:56.420
found in the first fortnight of the year.

459
00:17:56.900 --> 00:17:59.900
That tells you about the comet and then

460
00:17:59.900 --> 00:18:01.940
it's named after the discoverer in brackets.

461
00:18:02.580 --> 00:18:04.540
If the comet is seen at more than one

462
00:18:04.540 --> 00:18:06.780
apparition, the C gets changed to a P to show

463
00:18:06.780 --> 00:18:09.580
that it's periodic. In this

464
00:18:09.580 --> 00:18:12.020
case, because this already has

465
00:18:12.500 --> 00:18:15.340
an asteroidal name by which

466
00:18:15.340 --> 00:18:17.540
it's known, it's kept that, but they've added

467
00:18:17.540 --> 00:18:19.580
a P in front of it. So it's gone from being

468
00:18:19.580 --> 00:18:22.350
1998 SH2 to being

469
00:18:22.350 --> 00:18:25.150
P. 1998 SH2,

470
00:18:25.500 --> 00:18:28.030
um, will be interesting to see whether down

471
00:18:28.030 --> 00:18:29.910
the line they add the name of the discovery

472
00:18:29.910 --> 00:18:32.630
facility to it. Um, that wouldn't surprise

473
00:18:32.630 --> 00:18:34.670
me. That's been done for previous occasions

474
00:18:34.670 --> 00:18:36.390
where we've had an asteroid that became a

475
00:18:36.390 --> 00:18:38.710
comet. But it'll be interesting to see. But

476
00:18:38.710 --> 00:18:41.590
it's. I guess what I love about this is

477
00:18:41.590 --> 00:18:43.350
you get into the nitty gritty of it, but it's

478
00:18:43.350 --> 00:18:45.630
that reminder of the beautiful complexity

479
00:18:45.630 --> 00:18:47.710
we've got. There's so much more to learn.

480
00:18:48.510 --> 00:18:50.750
Andrew Dunkley: Absolutely, yes. Uh, it's a really good

481
00:18:50.750 --> 00:18:53.070
storey and, um, one worth reading up. You can

482
00:18:53.070 --> 00:18:55.790
do that@space.com or you can

483
00:18:55.790 --> 00:18:58.350
read the published findings in the journal

484
00:18:58.430 --> 00:19:01.310
Nature Astronomy. This is Space Nuts with

485
00:19:01.310 --> 00:19:03.790
Andrew Dunkley and Professor John T Horner.

486
00:19:06.350 --> 00:19:09.150
Jonti Horner: The crew of Artemis 2 now bound for the moon.

487
00:19:09.390 --> 00:19:11.790
Generic: Humanity's next great voyage begins.

488
00:19:12.510 --> 00:19:13.860
Jonti Horner: Space note Nuts.

489
00:19:13.940 --> 00:19:16.940
Andrew Dunkley: Let's move from a comet flying through

490
00:19:16.940 --> 00:19:19.900
space to a comet, uh, or an asteroid in this

491
00:19:19.900 --> 00:19:22.500
case, that stopped, uh, flying through space

492
00:19:22.500 --> 00:19:24.820
because a big planet called Earth got in the

493
00:19:24.820 --> 00:19:27.500
way. And the one

494
00:19:27.500 --> 00:19:29.850
that, um, is referred to as, uh,

495
00:19:30.740 --> 00:19:32.900
or creating the Chicxulub crater

496
00:19:33.380 --> 00:19:35.820
in what is now known, uh, as the Gulf of

497
00:19:35.820 --> 00:19:38.780
Mexico. Uh, and we even know the

498
00:19:38.780 --> 00:19:40.620
exact impact point because they've been down

499
00:19:40.620 --> 00:19:43.180
there and taken samples, uh, which was a very

500
00:19:43.180 --> 00:19:45.210
exciting storey when we covered that sometime

501
00:19:45.440 --> 00:19:47.960
back. But now they've taken another look at

502
00:19:47.960 --> 00:19:50.840
this, uh, and gone back to the very moment of

503
00:19:50.840 --> 00:19:53.720
impact and the few hours afterwards and

504
00:19:53.720 --> 00:19:56.640
decided by the look of it that this thing was

505
00:19:56.640 --> 00:19:58.320
much more brutal than

506
00:19:59.360 --> 00:20:00.560
we first envisaged.

507
00:20:02.320 --> 00:20:04.840
Jonti Horner: Absolutely. And this kind of ties in with the

508
00:20:04.840 --> 00:20:06.720
storeys that were told again. Back when I was

509
00:20:06.720 --> 00:20:09.280
a teenager, I remember hearing about the

510
00:20:10.080 --> 00:20:12.400
impact that killed the dinosaurs and storeys

511
00:20:12.400 --> 00:20:14.420
about what would have happened on the other

512
00:20:14.420 --> 00:20:17.220
side of the planet and the idea of firestorms

513
00:20:17.220 --> 00:20:18.820
and, you know, it was a hellish experience

514
00:20:18.980 --> 00:20:21.100
worldwide. But the way you'd normally hear

515
00:20:21.100 --> 00:20:23.740
this storey relatively recently is you had

516
00:20:23.740 --> 00:20:26.340
the impact. Things were bad in the vicinity

517
00:20:26.340 --> 00:20:28.460
of the impact. Shockwaves went out, tsunamis

518
00:20:28.460 --> 00:20:30.540
went out. So over a very large area, it was

519
00:20:30.540 --> 00:20:33.420
immediately fairly devastating. But

520
00:20:33.420 --> 00:20:35.420
there was a huge amount of dust and debris

521
00:20:35.420 --> 00:20:38.180
flung into the Earth's atmosphere, which led

522
00:20:38.180 --> 00:20:40.660
to this prolonged nuclear winter type event.

523
00:20:40.660 --> 00:20:42.580
You know, it blocked the sun, got really

524
00:20:42.580 --> 00:20:45.440
cold, the plants died, the animals died. Then

525
00:20:45.440 --> 00:20:47.360
when the clouds cleared, it got really,

526
00:20:47.360 --> 00:20:49.040
really nasty because you got this period of

527
00:20:49.040 --> 00:20:51.520
runaway global warming and hideous acid rain

528
00:20:51.760 --> 00:20:53.680
because the impact had hit rocks that were

529
00:20:53.920 --> 00:20:56.320
packed with carbon and sulphur

530
00:20:56.400 --> 00:20:58.670
carbonate and sulphate rocks, which led to,

531
00:20:58.670 --> 00:21:01.280
uh, carbonic and sulfuric acid

532
00:21:01.280 --> 00:21:04.000
rain. It led to an atmosphere super loaded

533
00:21:04.000 --> 00:21:06.880
with greenhouse gases. So it basically

534
00:21:06.880 --> 00:21:09.520
made the planet fairly hellish for a few tens

535
00:21:09.520 --> 00:21:11.600
of thousands of years, from one stage to the

536
00:21:11.600 --> 00:21:14.300
next to the next. But when I was

537
00:21:14.460 --> 00:21:16.420
younger, there were these storeys about while

538
00:21:16.420 --> 00:21:18.420
there were probably global firestorms. The

539
00:21:18.420 --> 00:21:20.700
idea that an impact halfway around the world

540
00:21:21.100 --> 00:21:23.580
could set fire to forests elsewhere.

541
00:21:24.300 --> 00:21:27.180
And in recent years I've not heard

542
00:21:27.180 --> 00:21:29.299
that storey told so much. It's kind of fallen

543
00:21:29.299 --> 00:21:31.740
a little bit out of fashion. But the new

544
00:21:31.740 --> 00:21:34.500
research that's been done here is kind of

545
00:21:34.500 --> 00:21:36.860
bringing that idea back into the picture.

546
00:21:37.500 --> 00:21:39.980
Now, the idea here is that you get this

547
00:21:40.140 --> 00:21:41.620
impactor that was probably about 10

548
00:21:41.620 --> 00:21:44.220
kilometres across, smacking into the Yukon

549
00:21:44.220 --> 00:21:47.020
Peninsula, creating a crater that was

550
00:21:47.020 --> 00:21:49.260
two to 300 kilometres in diameter.

551
00:21:50.060 --> 00:21:51.860
In doing that, it would have flung a huge

552
00:21:51.860 --> 00:21:54.780
amount of rocky material, vaporised material,

553
00:21:55.180 --> 00:21:57.460
out of the atmosphere. And a lot of that

554
00:21:57.460 --> 00:21:59.380
material would have travelled at speeds

555
00:21:59.380 --> 00:22:01.060
slower than the Earth's escape velocity to

556
00:22:01.060 --> 00:22:03.580
rain back down into the atmosphere. And when

557
00:22:03.580 --> 00:22:05.380
that material falls back into the atmosphere,

558
00:22:05.380 --> 00:22:07.300
it's travelling at speeds of kilometres per

559
00:22:07.300 --> 00:22:10.190
second, so it ablates like a

560
00:22:10.190 --> 00:22:11.750
fireball that we see in the sky, like a

561
00:22:11.750 --> 00:22:13.550
meteor. But you're not seeing one or two,

562
00:22:13.550 --> 00:22:15.630
you're seeing a huge deluge of material

563
00:22:15.630 --> 00:22:17.590
raining down all across the planet.

564
00:22:18.310 --> 00:22:21.230
Now, when these bits of material hit

565
00:22:21.230 --> 00:22:23.470
the atmosphere and ablate, what they're doing

566
00:22:23.470 --> 00:22:25.390
is they're taking the kinetic energy of their

567
00:22:25.390 --> 00:22:28.110
Martian and emitting, turning it into heat

568
00:22:28.110 --> 00:22:30.830
and light, which, you know, if you get a

569
00:22:30.830 --> 00:22:32.830
single small meteor, you're not gonna get

570
00:22:32.830 --> 00:22:35.070
sunburn from it. If you get something the

571
00:22:35.070 --> 00:22:36.710
size of the Chelyabinsk impact, people

572
00:22:36.710 --> 00:22:38.670
actually did get sunburn, um, from that, from

573
00:22:38.670 --> 00:22:41.290
the brightness of the flash. Now imagine,

574
00:22:41.290 --> 00:22:43.130
instead of having one Chelyabinsk impact,

575
00:22:43.130 --> 00:22:45.490
having this rain of material falling into the

576
00:22:45.490 --> 00:22:48.290
atmosphere all across the planet, creating

577
00:22:48.290 --> 00:22:50.450
this, what's described as a thermal pulse

578
00:22:51.410 --> 00:22:53.970
that has been discussed and

579
00:22:54.130 --> 00:22:55.970
previous models, things that have come out,

580
00:22:56.050 --> 00:22:58.130
suggested that that effect would have been

581
00:22:58.130 --> 00:23:01.010
like putting a grill on. It would have been

582
00:23:01.010 --> 00:23:03.050
really quite unpleasant for thin skinned

583
00:23:03.050 --> 00:23:04.770
animals that were exposed to it. You'd have

584
00:23:04.770 --> 00:23:07.170
got burned, you might even have got killed.

585
00:23:07.880 --> 00:23:09.920
But if you were, uh, underground or you were

586
00:23:09.920 --> 00:23:12.200
underwater, you'd have been able to live

587
00:23:12.200 --> 00:23:14.880
through it. I mean, you'd have lived to see

588
00:23:14.880 --> 00:23:16.200
all the other horrors that were coming from

589
00:23:16.200 --> 00:23:17.920
the impacts. It wasn't really a good news,

590
00:23:17.920 --> 00:23:19.640
Storey, but you'd have probably survived it.

591
00:23:20.200 --> 00:23:22.720
But the argument had been that that thermal

592
00:23:22.720 --> 00:23:24.440
pulse from that material coming into the

593
00:23:24.440 --> 00:23:26.920
atmosphere would not have got things hot

594
00:23:26.920 --> 00:23:29.480
enough to ignite things like grasses. You

595
00:23:29.480 --> 00:23:32.200
know, the tinder that you get that can start

596
00:23:32.200 --> 00:23:34.640
forest fires and things like this, which I

597
00:23:34.640 --> 00:23:36.240
think is why that idea of the global

598
00:23:36.240 --> 00:23:39.210
firestorms had gone away. What

599
00:23:39.210 --> 00:23:41.730
the new research has done is looking at

600
00:23:41.730 --> 00:23:43.930
fossil sites in North America, which must be

601
00:23:43.930 --> 00:23:45.570
remembered, was quite close to the impact,

602
00:23:46.130 --> 00:23:48.970
relatively speaking, on a global sense. They

603
00:23:48.970 --> 00:23:51.690
found this layer of spherules of material,

604
00:23:51.690 --> 00:23:53.530
which is a debris that rained back down to

605
00:23:53.530 --> 00:23:56.370
Earth, uh, in the fossil record and above it

606
00:23:56.370 --> 00:23:59.090
there's this very thin layer of silicate

607
00:23:59.090 --> 00:24:01.930
dust which must have fallen out at about the

608
00:24:01.930 --> 00:24:04.540
same time. Now the

609
00:24:04.540 --> 00:24:06.860
idea is that that silicate dust

610
00:24:07.340 --> 00:24:09.420
would have effectively acted like a bit of a

611
00:24:09.420 --> 00:24:11.860
doona with that raining down and that in the

612
00:24:11.860 --> 00:24:14.780
atmosphere. The fact that it's fallen in the

613
00:24:14.780 --> 00:24:17.740
fossil record above the spherules

614
00:24:17.740 --> 00:24:19.620
means the spherules got to the ground before

615
00:24:19.620 --> 00:24:22.500
the dust got to the ground, effectively. So

616
00:24:22.500 --> 00:24:24.020
the researchers have said, well, what would

617
00:24:24.020 --> 00:24:25.700
happen if you had all this dust, all this

618
00:24:25.700 --> 00:24:28.420
silicate dust in the atmosphere and you had

619
00:24:28.420 --> 00:24:30.860
these ferrules running through, giving off

620
00:24:30.860 --> 00:24:33.780
all this heat? And it's effectively like that

621
00:24:33.780 --> 00:24:36.060
dust in the atmosphere would have acted a bit

622
00:24:36.060 --> 00:24:38.020
like a reflecting, uh, blanket or something

623
00:24:38.020 --> 00:24:40.220
like that. It would have trapped even more of

624
00:24:40.220 --> 00:24:42.300
the heat in the atmosphere and reflected it

625
00:24:42.300 --> 00:24:44.300
back down at the ground. And, um, the

626
00:24:44.300 --> 00:24:47.300
calculations that they've made suggest that

627
00:24:47.300 --> 00:24:49.860
that extra energy, because of the energy

628
00:24:49.860 --> 00:24:51.620
being re radiated back down to the ground,

629
00:24:51.620 --> 00:24:54.420
rather than escaping to space, would have

630
00:24:54.420 --> 00:24:56.220
made things hot enough for grass to catch

631
00:24:56.220 --> 00:24:58.860
fire, for pine cones to catch fire. Not

632
00:24:58.860 --> 00:25:01.240
enough not for an entire tree to burst into

633
00:25:01.240 --> 00:25:03.600
flames, but for all the tinder that was lying

634
00:25:03.600 --> 00:25:06.280
on the ground to be called a flame.

635
00:25:06.920 --> 00:25:08.800
And if that happens, what you do is you

636
00:25:08.800 --> 00:25:11.800
trigger global firestorms. So you

637
00:25:11.800 --> 00:25:13.960
turn a situation and you make it much, much

638
00:25:13.960 --> 00:25:16.720
worse. Now, what should be said

639
00:25:16.720 --> 00:25:19.080
here is this, uh, work is looking at North

640
00:25:19.080 --> 00:25:22.000
America and it strikes me that further

641
00:25:22.000 --> 00:25:23.640
away from the impact site, you probably

642
00:25:23.640 --> 00:25:25.040
wouldn't have got the impact dust. So it

643
00:25:25.040 --> 00:25:26.640
might well be that you actually had a

644
00:25:26.640 --> 00:25:29.120
gradiated kind of level of nastiness from the

645
00:25:29.120 --> 00:25:31.620
impact. So nearby it brutal. And

646
00:25:32.100 --> 00:25:33.900
then you had the tsunamis and stuff washing

647
00:25:33.900 --> 00:25:36.220
out on the far side of the planet. You

648
00:25:36.220 --> 00:25:38.060
probably didn't get the silicate dust, so you

649
00:25:38.060 --> 00:25:40.100
just got the normal level of hellishness

650
00:25:40.500 --> 00:25:42.620
where you didn't set off firestorms, but

651
00:25:42.620 --> 00:25:44.700
things were nasty. But there was probably

652
00:25:44.700 --> 00:25:47.460
this sweet spot like the ultimately bad

653
00:25:47.460 --> 00:25:49.860
porridge in the Cinderella Storey, where

654
00:25:49.860 --> 00:25:52.500
things were ultimately worse, ultimately

655
00:25:52.820 --> 00:25:55.540
as bad as they could be, where the impact

656
00:25:55.620 --> 00:25:57.700
way over the horizon, way in the distance,

657
00:25:58.200 --> 00:26:00.440
was enough to trigger forests to burst into

658
00:26:00.440 --> 00:26:02.840
flame because of igniting the tinder enough

659
00:26:02.840 --> 00:26:05.840
to cook animals alive as they were on the

660
00:26:05.840 --> 00:26:08.600
surface. Uh, really kind of brutal and

661
00:26:08.600 --> 00:26:10.920
remarkably horrific imagery.

662
00:26:11.480 --> 00:26:14.239
But it's fascinating work and m it's another

663
00:26:14.239 --> 00:26:16.360
insight into just how bad impacts like this

664
00:26:16.360 --> 00:26:18.520
could be. It's that whole thing that we're

665
00:26:18.520 --> 00:26:21.400
playing with a detective storey that is 66

666
00:26:21.400 --> 00:26:23.880
million years old and we're trying to piece

667
00:26:23.880 --> 00:26:26.240
together the narrative of what happened and

668
00:26:26.240 --> 00:26:27.800
every bit of information we get like this

669
00:26:27.800 --> 00:26:29.560
just seems to make a more and more horrific

670
00:26:29.560 --> 00:26:30.260
piece picture.

671
00:26:30.580 --> 00:26:33.220
Andrew Dunkley: Yeah, I mean, the original consensus was

672
00:26:33.300 --> 00:26:35.940
the, um, asteroid hit

673
00:26:36.660 --> 00:26:39.060
the planet and, uh, it

674
00:26:39.060 --> 00:26:41.380
created, um, tsunamis that went around the

675
00:26:41.380 --> 00:26:43.780
world, um, three, four times, something like

676
00:26:43.780 --> 00:26:46.420
that. Um, and uh, created

677
00:26:47.220 --> 00:26:49.780
the equivalent of a nuclear winter and

678
00:26:49.860 --> 00:26:52.820
everything died and there was no food and,

679
00:26:52.850 --> 00:26:55.260
uh, the creatures died along with it over a

680
00:26:55.260 --> 00:26:58.260
period of time. But this is suggesting that a

681
00:26:58.260 --> 00:27:00.420
lot of, um, the initial death,

682
00:27:01.290 --> 00:27:03.630
uh, due to these firestorms happened in a few

683
00:27:03.790 --> 00:27:06.390
mere hours. Um, it's a

684
00:27:06.390 --> 00:27:07.310
horrifying thought.

685
00:27:08.110 --> 00:27:10.390
Jonti Horner: It is. And I mean, you start getting to that

686
00:27:10.390 --> 00:27:12.550
kind of philosophical side of thing is does

687
00:27:12.550 --> 00:27:14.510
this make it better or does it make it worse?

688
00:27:14.510 --> 00:27:15.910
You know, if you were there at the time,

689
00:27:15.910 --> 00:27:17.910
would you rather be broiled and baked and

690
00:27:17.910 --> 00:27:20.830
cooked quickly or left to starve slowly in

691
00:27:20.830 --> 00:27:23.350
the cold that followed it? Yeah, I mean it's

692
00:27:23.350 --> 00:27:25.750
all fairly bleak, but it is also that

693
00:27:25.750 --> 00:27:27.230
reminder drawing just a bit like we were

694
00:27:27.230 --> 00:27:28.630
talking about in the previous storey. We are

695
00:27:28.630 --> 00:27:30.510
in the crosshairs. This will happen again.

696
00:27:30.830 --> 00:27:32.670
It's not like the Earth has been hit for the

697
00:27:32.670 --> 00:27:35.430
last time unless we do something about

698
00:27:35.430 --> 00:27:38.070
it. And it's great that we have the capacity

699
00:27:38.070 --> 00:27:40.870
to discover objects further and further

700
00:27:40.870 --> 00:27:42.549
from the Earth with a greater and greater

701
00:27:42.549 --> 00:27:44.310
lead time before they come close to us. It's

702
00:27:44.310 --> 00:27:46.790
great that we're learning the capacity to

703
00:27:46.790 --> 00:27:49.110
deflect them. But it's sometimes hard to

704
00:27:49.110 --> 00:27:51.150
justify to people why people are doing this

705
00:27:51.150 --> 00:27:53.390
kind of research. And it's one of the

706
00:27:53.390 --> 00:27:55.070
arguments we have, for example, against the

707
00:27:55.070 --> 00:27:57.230
satellite megalithic constellations, because

708
00:27:57.230 --> 00:27:59.330
we're finally a spec that can look out at the

709
00:27:59.330 --> 00:28:02.010
cosmos and detect threats. And what we're

710
00:28:02.010 --> 00:28:04.130
doing is we're throwing tinsel in the way and

711
00:28:04.130 --> 00:28:04.970
hiding the view.

712
00:28:06.330 --> 00:28:08.570
Andrew Dunkley: And that is a bit of a worry. Well, it's a

713
00:28:08.570 --> 00:28:10.770
big worry and it's not getting any better. In

714
00:28:10.770 --> 00:28:13.470
fact, it's going to get worse. We'll um,

715
00:28:13.470 --> 00:28:15.530
probably discuss that more in our next

716
00:28:15.530 --> 00:28:15.930
episode.

717
00:28:15.930 --> 00:28:18.650
But, um, I did notice

718
00:28:18.650 --> 00:28:21.130
in sort of looking at this storey that, uh,

719
00:28:21.130 --> 00:28:24.130
some papers or some websites refer to

720
00:28:24.130 --> 00:28:26.330
it as a meteorite impact rather than an

721
00:28:26.330 --> 00:28:28.430
asteroid. Why would they do that?

722
00:28:28.910 --> 00:28:31.790
Jonti Horner: This is interesting with terminology and

723
00:28:31.950 --> 00:28:34.030
I'm less uncomfortable with the idea of

724
00:28:34.270 --> 00:28:37.070
meteorite impact, asteroid impact being

725
00:28:37.070 --> 00:28:39.990
a conflation. The terminology of

726
00:28:39.990 --> 00:28:42.590
objects is a weird one and

727
00:28:42.989 --> 00:28:45.550
astronomers have very specific terminology

728
00:28:46.350 --> 00:28:48.310
that then gets a little bit confused when you

729
00:28:48.310 --> 00:28:50.470
see popular science and you see the news and

730
00:28:50.470 --> 00:28:53.270
all the rest of it when something's floating

731
00:28:53.270 --> 00:28:56.210
around in space nowhere near the Earth,

732
00:28:56.690 --> 00:28:59.570
we refer to it as a meteoroid

733
00:28:59.570 --> 00:29:01.810
or an asteroid or comet, basically.

734
00:29:02.560 --> 00:29:04.170
Um, and we talked about asteroids and comets

735
00:29:04.170 --> 00:29:05.890
earlier on and where the line blurs there.

736
00:29:07.090 --> 00:29:09.890
The typical boundary between

737
00:29:09.890 --> 00:29:12.850
calling a meteoroid and an asteroid is

738
00:29:12.850 --> 00:29:15.130
often taken as being about one metre in size,

739
00:29:15.130 --> 00:29:16.610
but that's just fairly arbitrary.

740
00:29:18.130 --> 00:29:21.040
When something enters the atmosphere and it's

741
00:29:21.040 --> 00:29:22.320
pushing the air in front of it and it's

742
00:29:22.320 --> 00:29:25.320
glowing in the sky, that phenomenon we call

743
00:29:25.320 --> 00:29:28.200
a meteor, if it's really bright, we call it

744
00:29:28.200 --> 00:29:30.160
a fireball. And that boundary is set roughly

745
00:29:30.160 --> 00:29:32.680
as bright as a planet Venus. If we see an

746
00:29:32.680 --> 00:29:34.800
explosion at the end, we call it a bolide.

747
00:29:34.800 --> 00:29:36.480
And that just means exploding fireball,

748
00:29:36.640 --> 00:29:39.440
basically. So meteor, bolide,

749
00:29:39.600 --> 00:29:42.080
fireball are uh, atmospheric phenomena.

750
00:29:42.320 --> 00:29:43.880
You're not actually seeing the thing coming

751
00:29:43.880 --> 00:29:46.080
through the atmosphere, you're seeing the gas

752
00:29:46.080 --> 00:29:48.550
that it's heated up and excited in the

753
00:29:48.550 --> 00:29:50.310
atmosphere. That's what you're seeing as a

754
00:29:50.310 --> 00:29:53.190
glow. When it reaches the ground and hits the

755
00:29:53.190 --> 00:29:55.750
ground, you call it a meteorite. That's the

756
00:29:55.750 --> 00:29:58.630
physical object on the ground or hitting the

757
00:29:58.630 --> 00:30:01.590
ground. Now, whether

758
00:30:01.590 --> 00:30:04.110
you call something like this a meteorite

759
00:30:04.110 --> 00:30:05.950
impact or an asteroid impact, I think it's

760
00:30:05.950 --> 00:30:08.870
probably both. You know, technically the

761
00:30:08.870 --> 00:30:11.870
asteroid hits the ground, um, you

762
00:30:11.870 --> 00:30:13.910
could call it a meteorite. But maybe what you

763
00:30:13.910 --> 00:30:15.670
should do is have that idea in your head of

764
00:30:15.670 --> 00:30:17.830
if it's less than a metre across, you could

765
00:30:17.830 --> 00:30:19.930
call it a meteorite. Bigger than that, you'd

766
00:30:19.930 --> 00:30:21.210
call it an asteroid. I've never seen

767
00:30:21.210 --> 00:30:24.130
clarification on where that

768
00:30:24.130 --> 00:30:26.290
boundary comes because terms are used in

769
00:30:26.290 --> 00:30:29.130
different sensors kind of thing. So for me,

770
00:30:29.290 --> 00:30:31.090
I don't think it's unreasonable to say

771
00:30:31.090 --> 00:30:32.890
meteorite impact here, although you're

772
00:30:32.890 --> 00:30:35.450
probably pushing the size definition.

773
00:30:36.010 --> 00:30:38.330
Call it an asteroid or comet impact is

774
00:30:38.330 --> 00:30:40.130
probably more reasonable. And it might be

775
00:30:40.130 --> 00:30:42.050
that if you dug into the physics of it and

776
00:30:42.050 --> 00:30:44.930
you were to do an IAU resolution a bit like

777
00:30:44.930 --> 00:30:47.930
we did with Pluto, maybe what you do is look

778
00:30:47.930 --> 00:30:49.610
at it in terms of the effect of the

779
00:30:49.610 --> 00:30:52.330
atmosphere on the object coming in. So

780
00:30:52.330 --> 00:30:54.770
things that create fireballs and bolides in

781
00:30:54.770 --> 00:30:57.370
day to day life, the atmosphere is much

782
00:30:57.370 --> 00:31:00.210
bigger in size than the object coming in,

783
00:31:00.370 --> 00:31:02.330
which means wind resistance will eventually

784
00:31:02.330 --> 00:31:05.130
slow it down. So the meteorite that we talked

785
00:31:05.130 --> 00:31:06.650
about a few months ago that landed on

786
00:31:06.650 --> 00:31:09.330
someone's driveway in Canada was travelling

787
00:31:09.330 --> 00:31:11.490
at about the same speed that a rock dropped

788
00:31:11.490 --> 00:31:12.970
out of an aircraft would have done. It was at

789
00:31:12.970 --> 00:31:15.810
terminal velocity. Its speed was

790
00:31:15.810 --> 00:31:18.330
governed by the atmosphere. Whereas with

791
00:31:18.330 --> 00:31:20.950
things that are kilometre scale, the

792
00:31:20.950 --> 00:31:22.710
Atmosphere is essentially not there. It's not

793
00:31:22.710 --> 00:31:25.270
going to slow them down. And so I wonder

794
00:31:25.270 --> 00:31:26.990
whether there is an argument that you could

795
00:31:26.990 --> 00:31:29.590
set up a definition that said if it's

796
00:31:29.590 --> 00:31:31.870
travelling at uh, speed less than

797
00:31:31.870 --> 00:31:34.710
supersonic, you'd call it a meteorite impact.

798
00:31:34.710 --> 00:31:36.309
If it's travelling faster than that, maybe

799
00:31:36.309 --> 00:31:38.990
you'd call it an asteroid impact. But I don't

800
00:31:38.990 --> 00:31:40.910
think that there's any official delineation

801
00:31:40.990 --> 00:31:43.350
like that. That's just kind of how I think

802
00:31:43.350 --> 00:31:44.590
about things in my own head.

803
00:31:44.670 --> 00:31:46.760
Andrew Dunkley: No, I like that that works. Well, well,

804
00:31:46.760 --> 00:31:48.560
that's probably a good way to think about it.

805
00:31:49.420 --> 00:31:52.000
Um, another interesting storey that uh, the

806
00:31:52.000 --> 00:31:54.960
asteroid impact uh, that killed the dinosaurs

807
00:31:55.280 --> 00:31:57.720
was a lot more damaging in the early stages

808
00:31:57.720 --> 00:32:00.240
than we first thought by the look of. But uh,

809
00:32:00.240 --> 00:32:02.400
plenty of, plenty of websites and news

810
00:32:02.640 --> 00:32:04.360
platforms have picked this one up, not

811
00:32:04.360 --> 00:32:06.720
surprisingly. Uh, but you can read

812
00:32:07.760 --> 00:32:10.280
at uh, the Science

813
00:32:10.280 --> 00:32:13.160
Advances, uh, website published in

814
00:32:13.160 --> 00:32:15.600
Science Advances. Uh, this is Space Nuts

815
00:32:15.600 --> 00:32:17.440
Andrew Dunkley here with Johnty Horner.

816
00:32:20.220 --> 00:32:22.140
Jonti Horner: 0G and I feel fine.

817
00:32:22.140 --> 00:32:24.940
Andrew Dunkley: Space Nuts, the storey. Jonty

818
00:32:25.020 --> 00:32:27.740
takes us to Canadia and

819
00:32:27.900 --> 00:32:30.620
this is a storey, uh, about a

820
00:32:30.620 --> 00:32:33.620
Canadian amateur astronomer who

821
00:32:33.620 --> 00:32:36.140
decided to plan a holiday using online maps.

822
00:32:36.140 --> 00:32:36.620
It is.

823
00:32:36.620 --> 00:32:38.380
Jonti Horner: This is lovely. I think we've all done this

824
00:32:38.380 --> 00:32:41.140
to some degree. You planning your holiday,

825
00:32:41.140 --> 00:32:42.700
planning your road trip. I just had a lovely

826
00:32:42.700 --> 00:32:45.230
holiday with the in laws. And you look at uh,

827
00:32:45.230 --> 00:32:47.140
the online maps of your choice that typically

828
00:32:47.140 --> 00:32:49.140
have really nice satellite images of the

829
00:32:49.140 --> 00:32:52.110
places you're um, and you try and figure out

830
00:32:52.110 --> 00:32:53.230
what you're going to see, what you're going

831
00:32:53.230 --> 00:32:55.990
to go there. And to some degree you sat

832
00:32:55.990 --> 00:32:57.510
browsing around thinking, I wonder if I can

833
00:32:57.510 --> 00:32:59.230
see anything unusual, what's it like around

834
00:32:59.230 --> 00:33:02.030
there? And that's what happened

835
00:33:02.030 --> 00:33:05.030
here. We've got this amateur astronomer going

836
00:33:05.030 --> 00:33:08.030
by the name of Joel Lapointe who back in

837
00:33:08.030 --> 00:33:10.990
2024 was planning his hiking and

838
00:33:10.990 --> 00:33:13.830
camping trip. And I think it's in northern

839
00:33:13.830 --> 00:33:16.350
Quebec. It's near a place called Lake Mars.

840
00:33:17.620 --> 00:33:20.340
And he found this unusual looking

841
00:33:20.820 --> 00:33:23.220
feature next to that lake. Looks a bit odd

842
00:33:23.620 --> 00:33:26.420
on the maps on the satellite imaging. Now

843
00:33:26.420 --> 00:33:29.300
there is a university in Canada that has a

844
00:33:29.300 --> 00:33:31.820
website called Impact Earth that allows

845
00:33:31.820 --> 00:33:34.020
people to, as a kind of popular

846
00:33:34.570 --> 00:33:36.500
um, collaborative endeavour for

847
00:33:36.980 --> 00:33:39.060
citizen science is the word I'm looking for

848
00:33:39.460 --> 00:33:42.260
to log things where people think they've

849
00:33:42.260 --> 00:33:45.250
found impact features. So being an

850
00:33:45.250 --> 00:33:46.930
amateur astronomer being aware of this, he

851
00:33:46.930 --> 00:33:49.690
logged it. I think I found a crater. About

852
00:33:49.690 --> 00:33:52.410
a year later, um, the site

853
00:33:52.490 --> 00:33:54.970
as a result of this report was

854
00:33:55.210 --> 00:33:57.730
explored, visited by a planetary geologist

855
00:33:57.730 --> 00:34:00.250
from the university called Gordon Ozinski.

856
00:34:00.810 --> 00:34:03.050
Who went there, took a lot of samples,

857
00:34:03.290 --> 00:34:06.130
explored around and confirmed that

858
00:34:06.130 --> 00:34:07.890
this really is an impact feature. It's an

859
00:34:07.890 --> 00:34:09.780
impact crater about

860
00:34:10.020 --> 00:34:12.900
390 million years old,

861
00:34:12.980 --> 00:34:14.940
so way older than the impact that killed the

862
00:34:14.940 --> 00:34:17.780
dinosaurs. About 25 kilometres

863
00:34:17.780 --> 00:34:20.580
across, which includes a load of

864
00:34:20.580 --> 00:34:23.460
incredibly well preserved features in terms

865
00:34:23.460 --> 00:34:26.260
of glassy hardened volcanic type rocks from

866
00:34:26.260 --> 00:34:29.180
the impact that he himself has said he's

867
00:34:29.180 --> 00:34:30.860
surprised at that well preserved, given how

868
00:34:30.860 --> 00:34:33.420
old it is and how far north this is, how cold

869
00:34:33.420 --> 00:34:36.140
the weather gets in the winter and stuff. Now

870
00:34:36.140 --> 00:34:38.260
this makes it the biggest crater found on

871
00:34:38.260 --> 00:34:40.740
Earth since 2018, when there was a crater

872
00:34:40.960 --> 00:34:43.480
discovered under the Greenland ice sheet. But

873
00:34:43.480 --> 00:34:45.120
the difference is that the one under the

874
00:34:45.120 --> 00:34:47.400
Greenland ice sheet is below a kilometre's

875
00:34:47.400 --> 00:34:50.040
depth of ice. So it isn't like we can get

876
00:34:50.040 --> 00:34:51.800
there and learn much more about it. That's

877
00:34:51.800 --> 00:34:53.360
still quite a mysterious spot.

878
00:34:54.320 --> 00:34:56.880
Whereas this is open and exposed and

879
00:34:56.880 --> 00:34:59.600
accessible, so people are able to go there

880
00:34:59.600 --> 00:35:02.280
and explore it, learn a lot about it. There's

881
00:35:02.280 --> 00:35:04.720
some really nice imagery out there on the

882
00:35:05.040 --> 00:35:07.800
Internet about this. From the maps, images

883
00:35:07.800 --> 00:35:10.540
where it was found to images of

884
00:35:10.540 --> 00:35:12.740
features called shatter cones, which are the

885
00:35:12.740 --> 00:35:15.060
kind of thing created that are very typical

886
00:35:15.060 --> 00:35:17.780
of an impact crater formed under very high

887
00:35:17.780 --> 00:35:20.580
pressure, very high temperature molten rock.

888
00:35:20.580 --> 00:35:23.020
So it is absolutely amazing.

889
00:35:23.420 --> 00:35:26.140
But it's also to me kind of breathtaking that

890
00:35:26.140 --> 00:35:29.020
here is a feature 25 kilometres in diameter

891
00:35:29.980 --> 00:35:32.500
in the middle of a built up, well, not that

892
00:35:32.500 --> 00:35:34.660
built up country, but in the middle of a

893
00:35:34.660 --> 00:35:37.640
country near a famous lake, there is an

894
00:35:37.640 --> 00:35:39.800
impact crater that had never been identified

895
00:35:39.800 --> 00:35:42.360
until now. You know, we're still discovering

896
00:35:43.000 --> 00:35:45.320
kilometres, tens of kilometre scale features

897
00:35:45.320 --> 00:35:47.120
on the Earth. I mean, that's just

898
00:35:47.120 --> 00:35:47.960
astonishing.

899
00:35:50.460 --> 00:35:53.440
Andrew Dunkley: Uh, yeah, it is. And um, I

900
00:35:53.440 --> 00:35:56.000
think we've talked about it in the past that

901
00:35:56.000 --> 00:35:58.040
one of the problems with finding these things

902
00:35:58.040 --> 00:36:00.880
on Earth is the fact that the Earth's kind

903
00:36:00.880 --> 00:36:03.330
of covered up with vegetation and uh,

904
00:36:03.800 --> 00:36:06.180
you know, lots of, um, weather, uh,

905
00:36:06.520 --> 00:36:08.700
activity which has caused erosion and then

906
00:36:08.700 --> 00:36:10.220
we've got earthquakes that have caused

907
00:36:10.220 --> 00:36:12.500
mountain ranges to pop up here and there. And

908
00:36:12.500 --> 00:36:15.380
so a lot of these impact points get uh,

909
00:36:15.540 --> 00:36:18.260
disturbed or are hidden. Not uncommon

910
00:36:18.260 --> 00:36:18.580
now.

911
00:36:20.100 --> 00:36:22.380
Jonti Horner: Absolutely. And I mean 70% of the Earth's

912
00:36:22.380 --> 00:36:25.260
surface is water and you need to be a bigger

913
00:36:25.260 --> 00:36:27.140
impacter than the depth of the ocean to leave

914
00:36:27.140 --> 00:36:29.860
a scar on the ocean floor. So the

915
00:36:30.260 --> 00:36:32.820
history of impacts on the Earth is very much

916
00:36:32.820 --> 00:36:35.160
muddied by all of these different

917
00:36:35.240 --> 00:36:37.560
processes. The Ice Ages have scoured the

918
00:36:37.560 --> 00:36:39.080
surface of the Earth clean. We've got

919
00:36:39.080 --> 00:36:41.400
weathering, we've got forests, the Earth's

920
00:36:41.400 --> 00:36:43.480
surface is actually an incredibly dynamic

921
00:36:43.480 --> 00:36:46.280
place compared to the Moon. If you look at

922
00:36:46.280 --> 00:36:48.000
the Moon, there are many craters of this kind

923
00:36:48.000 --> 00:36:50.000
of size. And one of the things that is

924
00:36:50.000 --> 00:36:51.600
actually discussed in the articles online

925
00:36:51.600 --> 00:36:54.160
about this is whether this could be a venue

926
00:36:54.160 --> 00:36:56.320
for people to learn more in preparation for

927
00:36:56.320 --> 00:36:58.600
visits to the Moon where we can go to craters

928
00:36:58.680 --> 00:37:00.720
or vice versa. Whether we could learn more

929
00:37:00.720 --> 00:37:02.680
about craters like this by going to the ones

930
00:37:02.680 --> 00:37:04.240
on the Moon that are the same size but are

931
00:37:04.240 --> 00:37:06.840
pristine because we're at a similar

932
00:37:06.840 --> 00:37:08.960
location with similar targets in the shooting

933
00:37:08.960 --> 00:37:11.440
gallery. But on the Earth everything gets

934
00:37:11.440 --> 00:37:13.400
worn away fairly effectively, whereas on the

935
00:37:13.400 --> 00:37:16.200
Moon it stays pretty pristine until something

936
00:37:16.200 --> 00:37:18.360
else hits it and weathers it away. The only

937
00:37:18.360 --> 00:37:19.880
real way you're going to weather lunar

938
00:37:19.880 --> 00:37:22.680
craters, um, with a few exceptions, is

939
00:37:22.680 --> 00:37:24.720
by other things hitting them and muddying the

940
00:37:24.720 --> 00:37:27.600
water. There is going to be a lot more to

941
00:37:27.600 --> 00:37:30.560
learn about this. It is still relatively new

942
00:37:30.560 --> 00:37:32.770
news. The geologists involved

943
00:37:33.170 --> 00:37:35.050
won't be going there year round because it

944
00:37:35.050 --> 00:37:36.890
gets really, really cold and really

945
00:37:36.890 --> 00:37:38.410
unpleasant in the winter. So there'll be

946
00:37:38.410 --> 00:37:40.170
summer expeditions going there, trying to

947
00:37:40.170 --> 00:37:42.810
learn more about it, getting more and more

948
00:37:42.810 --> 00:37:44.530
samples of it. Because we don't know many

949
00:37:44.530 --> 00:37:46.210
craters that are that old on the Earth.

950
00:37:46.290 --> 00:37:49.050
Andrew Dunkley: No, this is 390 million

951
00:37:49.050 --> 00:37:51.890
years. That's a long time back, isn't

952
00:37:51.890 --> 00:37:54.730
it? That's over 300 million years beyond the

953
00:37:54.730 --> 00:37:55.730
dinosaur impact.

954
00:37:56.930 --> 00:37:59.290
Jonti Horner: Absolutely pretty impressive. It's far from

955
00:37:59.290 --> 00:38:01.010
the oldest crater on the Earth, but I would

956
00:38:01.330 --> 00:38:04.050
argue that we know far more younger craters

957
00:38:04.290 --> 00:38:06.410
than this than. We know older craters than

958
00:38:06.410 --> 00:38:06.690
this.

959
00:38:06.690 --> 00:38:09.570
Andrew Dunkley: Yeah. Didn't they recently say they found

960
00:38:09.570 --> 00:38:12.050
the oldest one in Western Australia? Was it?

961
00:38:12.930 --> 00:38:15.050
Jonti Horner: Yeah. Then I think that was a little bit

962
00:38:15.050 --> 00:38:16.810
controversial, but there was a lot of talk

963
00:38:16.810 --> 00:38:18.850
about shattercons with that one as well.

964
00:38:18.850 --> 00:38:20.690
Andrew Dunkley: Yes, there was, Yeah, I remember that.

965
00:38:21.090 --> 00:38:23.450
Jonti Horner: You know, these are, uh, we're finding

966
00:38:23.450 --> 00:38:25.210
craters more and more and they tell us about

967
00:38:25.210 --> 00:38:27.790
the history of the Earth and the heritage of

968
00:38:27.790 --> 00:38:30.710
it. With the really old craters, there's even

969
00:38:30.710 --> 00:38:33.310
some arguments that the, ah, largest impacts

970
00:38:33.310 --> 00:38:35.190
that happened very early on in the Earth's

971
00:38:35.190 --> 00:38:38.110
history were actually the seeds of the

972
00:38:38.110 --> 00:38:40.150
continents to some degree. There was some

973
00:38:40.390 --> 00:38:43.270
amazing work. This is probably actually best

974
00:38:43.270 --> 00:38:45.110
part of a decade ago now. But there was great

975
00:38:45.110 --> 00:38:47.070
work by Craig o' Neill and his team that were

976
00:38:47.070 --> 00:38:50.030
looking at trying to model the initiation of

977
00:38:50.030 --> 00:38:51.630
plate tectonics on the Earth. So how did

978
00:38:51.630 --> 00:38:53.750
plate tectonics get going? And, um, these

979
00:38:53.750 --> 00:38:55.870
incredibly talented geophysicists here in

980
00:38:55.870 --> 00:38:58.820
Australia were running models where

981
00:38:58.820 --> 00:39:00.860
you start the Earth with no plate tectonics,

982
00:39:00.860 --> 00:39:02.540
looking at the interior, looking at how hot

983
00:39:02.540 --> 00:39:04.940
it was back then. And if you started the

984
00:39:04.940 --> 00:39:06.420
Earth without plate tectonics, plate

985
00:39:06.420 --> 00:39:08.900
tectonics didn't happen. And uh, what they

986
00:39:08.900 --> 00:39:11.380
thought could be the smoking gun was that you

987
00:39:11.380 --> 00:39:14.340
had impacts that caused a big impulse of

988
00:39:14.340 --> 00:39:16.860
energy and motion in the mantle

989
00:39:17.180 --> 00:39:19.700
that triggered a downwelling which would then

990
00:39:19.700 --> 00:39:21.340
trigger an upwelling and you could get impact

991
00:39:21.580 --> 00:39:24.300
induced plate tectonics which would then

992
00:39:24.300 --> 00:39:26.340
cause these things to maybe even give you the

993
00:39:26.340 --> 00:39:28.100
seeds of the continents of the earliest

994
00:39:28.100 --> 00:39:31.040
continents. And that's an

995
00:39:31.040 --> 00:39:32.960
awesome storey. The videos that they made of

996
00:39:32.960 --> 00:39:35.620
their simulations were fabulous. And

997
00:39:35.620 --> 00:39:37.520
um, yeah, it's amazing what more there is

998
00:39:37.520 --> 00:39:38.520
still to learn, I guess.

999
00:39:38.680 --> 00:39:41.120
Andrew Dunkley: Yeah, absolutely true. And this is another

1000
00:39:41.120 --> 00:39:43.880
storey that's been picked up by Orlin Sundry.

1001
00:39:44.420 --> 00:39:46.640
Uh, so, um, yeah, you shouldn't have any

1002
00:39:46.640 --> 00:39:48.720
trouble finding it if you do, um, a search

1003
00:39:48.720 --> 00:39:51.040
for the Canadian amateur astronomer who was

1004
00:39:51.040 --> 00:39:53.800
planning his holiday. And uh, the storey will

1005
00:39:53.800 --> 00:39:56.080
pop up just about everywhere. Space.com, the

1006
00:39:56.080 --> 00:39:58.280
Smithsonian magazine, et cetera, et cetera.

1007
00:39:58.600 --> 00:40:01.540
Uh, and uh, by, by now,

1008
00:40:01.620 --> 00:40:04.460
when you hear this episode or very close to

1009
00:40:04.460 --> 00:40:07.220
this point in time, uh, the team

1010
00:40:07.220 --> 00:40:09.020
that uh, made the discovery will be

1011
00:40:09.020 --> 00:40:11.780
presenting their work at the 88th Annual

1012
00:40:11.780 --> 00:40:14.280
Meeting of the Meteor. Uh,

1013
00:40:14.280 --> 00:40:17.100
meteoritis. I can't say

1014
00:40:17.100 --> 00:40:20.060
it, uh, Meteorocital

1015
00:40:20.060 --> 00:40:22.780
Society in Germany, I think. That's right. I

1016
00:40:22.780 --> 00:40:25.380
don't know. Anyway, yeah, look it up. It's a

1017
00:40:25.380 --> 00:40:25.900
great yarn.

1018
00:40:25.900 --> 00:40:28.660
Uh, we've had a very rocky programme today.

1019
00:40:29.300 --> 00:40:32.260
Um, Jonty, it's been fascinating the

1020
00:40:32.260 --> 00:40:34.540
way those storeys all dovetailed into each

1021
00:40:34.540 --> 00:40:36.980
other. Uh, and we're at the end. Thank you

1022
00:40:36.980 --> 00:40:38.540
very much. Nice to see you again.

1023
00:40:39.200 --> 00:40:40.500
Jonti Horner: Uh, it's good to be back. Thank you for

1024
00:40:40.500 --> 00:40:41.260
having me and hope

1025
00:40:41.260 --> 00:40:43.260
Andrew Dunkley: Fred Watson's enjoying his jaunt

1026
00:40:44.220 --> 00:40:45.860
chasing a, uh, solar eclipse.

1027
00:40:45.860 --> 00:40:48.340
Jonti Horner: Yes, yes, it's a hard life but somebody's got

1028
00:40:48.340 --> 00:40:48.860
to do it.

1029
00:40:48.940 --> 00:40:50.860
Andrew Dunkley: Absolutely true. I'm waiting for one to come

1030
00:40:50.860 --> 00:40:52.620
to me. I only have to wait two more years.

1031
00:40:52.700 --> 00:40:53.500
Jonti Horner: Two more years.

1032
00:40:54.300 --> 00:40:54.700
Andrew Dunkley: Thanks.

1033
00:40:54.700 --> 00:40:56.220
Jonti Horner: And it'll be cloudy. You know it's going to

1034
00:40:56.220 --> 00:40:56.540
be cloudy.

1035
00:40:56.540 --> 00:40:57.780
Andrew Dunkley: Oh yeah, it's probably going to be raining

1036
00:40:57.850 --> 00:41:00.530
training and I'm m giving up a game of golf

1037
00:41:00.530 --> 00:41:02.970
for it too. All right, thanks Jonty. We'll

1038
00:41:02.970 --> 00:41:05.010
see you soon. Yeah, It's a pleasure,

1039
00:41:05.010 --> 00:41:06.690
Professor Jonty Horner, professor of

1040
00:41:06.690 --> 00:41:08.850
Astrophysics at the University of Southern

1041
00:41:08.850 --> 00:41:11.130
Queensland. Don't forget, uh, to visit us

1042
00:41:11.130 --> 00:41:13.530
online while uh, you are, ah, waiting for the

1043
00:41:13.530 --> 00:41:14.290
next episode,

1044
00:41:14.290 --> 00:41:16.650
spacenutspodcast.com

1045
00:41:17.370 --> 00:41:18.810
and have a look around while you're there.

1046
00:41:18.810 --> 00:41:21.450
Visit the shop, etc etc and thanks to Huw in

1047
00:41:21.450 --> 00:41:23.730
the studio couldn't be with us today. Um, put

1048
00:41:23.730 --> 00:41:25.490
his home address in Google Maps. We haven't

1049
00:41:25.490 --> 00:41:27.810
seen him since. And from me, Andrew Dunkley.

1050
00:41:27.810 --> 00:41:29.610
Thanks for your company. We'll see you on the

1051
00:41:29.610 --> 00:41:31.830
next next episode of Space Nuts. Bye. Bye.

1052
00:41:33.030 --> 00:41:35.230
Jonti Horner: You've been listening to the Space Nuts

1053
00:41:35.230 --> 00:41:38.190
podcast, available at

1054
00:41:38.190 --> 00:41:40.150
Apple Podcasts, Spotify,

1055
00:41:40.390 --> 00:41:43.150
iHeartRadio or your favourite podcast

1056
00:41:43.150 --> 00:41:44.830
player. You can also stream on

1057
00:41:44.830 --> 00:41:46.470
demand@bytes.com M.

1058
00:41:46.870 --> 00:41:48.950
Andrew Dunkley: This has been another quality podcast

1059
00:41:48.950 --> 00:41:51.030
production from bytes.com.