Primordial Black Holes, Planetary Chemistry & Lunar Crater Discoveries

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Andrew Dunkley: Hello once again, thanks for joining us. This

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is Space Nuts. My name is Andrew Dunkley.

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It's great to have your company. We talk

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astronomy and space science on this show and

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we hope you enjoy it. Uh, all five listeners

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have actually said at some stage or another

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in the last decade that they did enjoy one or

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two episodes out of the 618 we've done. So

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that's a pretty good record. Uh, but we'll

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press on. We'll press on. Uh, what we've got

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coming up for you today is extraordinary.

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We're going to talk about, uh, black holes.

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Uh, these ones though, uh, are only thought

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to exist. But they're starting to piece

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together evidence that they are. And

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we're talking about primordial black holes.

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But what's really interesting is

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how they all began. Maybe we'll

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get into that. Uh, and uh, planets

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and their chemical makeup compared to their

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parent star. There's been a major discovery

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there. And a fresh moon crater, a

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big one. You could put a couple

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hundred thousand people in this one, uh, to

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watch a football game. Uh, that's all coming

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up 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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Professor Fred Watson: Space nuts.

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

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5, 5, 4, 3, 2, 1.

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Andrew Dunkley: Space nuts.

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Generic: Astronauts report it feels good.

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Andrew Dunkley: And back once again to fill in the blanks is

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Professor Fred Watson Watson, astronomer at

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large. Hello, Fred Watson.

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Professor Fred Watson: Hi, Andrew. Um, I do apologise for

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my pre broadcast sneeze there that I hope you

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didn't pick up on the headphones.

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Andrew Dunkley: I'll have to listen back, but that's okay. I

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mean, we've got everything that happens on

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this show.

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Professor Fred Watson: Yeah,

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Andrew Dunkley: I used to actually welcome that stuff on my

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radio show because, um, I just thought it

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made everything more human. If you had

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somebody sneezing or tripping over or banging

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a wall or walking in on you.

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That was always fun. Um,

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ye. I. My philosophy was

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if you walk in, you're in the show. End of

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storey. Um, nobody really

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escaped. Uh, how are things Fred Watson, by

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the way?

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Professor Fred Watson: Uh, fine, I think. Yes. I don't know why I

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sneezed. I think I um, might have caught the

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lurgy that you.

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Andrew Dunkley: Oh yeah, I've got a bit of something. We took

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the grandchildren out and took them, took

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them to a place called Inflatable World.

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Okay. You jump in castles and slides and,

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you know, air guns and things. Not the ones

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that fire lead pellets, but, uh, they fire,

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you know, plastic balls. Uh, they had a great

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time but um, I fear because there were

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10 million kids there, um, and half of

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them had lots of stuff coming out their nose.

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I might caught something.

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Might have caught something there.

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Professor Fred Watson: I can't say I've noticed anything coming out

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of your nose. So you.

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Andrew Dunkley: Well, just hang around. Just hang around.

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I'm all dosed up. It dries you out, that

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stuff. It's good. That's why they've made it

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illegal.

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Well, no, it's behind the counter now, I

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think is the rule. You can't get it off the

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shelf. You've got to ask the pharmacist for

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the. For the good state. But it is good

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stuff. Good stuff. All right, let's carry on.

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My voice is already starting to fail me. Uh,

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Fred Watson, let's.

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Let's begin because this is a really exciting

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storey. Uh, we have talked many times about

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black holes, about, um,

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dark matter, um, and we've talked

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about primordial black holes. And now they're

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starting to think maybe there's a

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relationship there. We've got to prove one

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that might prove the other, which might solve

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the problem of dark matter. Am I right about

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that? That theory?

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Professor Fred Watson: Yes, you're right. You are right, yes. In

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fact, you've told the storey in a much more

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succinct way than I'm going to now.

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Andrew Dunkley: Okay, well, that's going to make things fast.

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Professor Fred Watson: So, um. So this is a storey from

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ligo, the Large Interferometric

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Gravitational Wave Observatory, which has

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two, uh, um, locations, two

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detectors, one in Washington, one in

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Louisiana. Uh, and

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the, I mean, the first of those,

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um, detections was quite a number of years

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ago now. Uh, so we've known about these

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gravitational waves. I think it was. Might

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even have been 2015. Um,

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I, um, might be confusing. I do remember it

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was, uh. The detection was on Marnie's

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birthday, the 14th of September. So. Cool. I

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can't remember what year it was. Anyway,

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whatever it was, uh, it was a good year

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because for the first time we could sense the

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collisions of, um, objects

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colliding in space. Sorry, there's

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tautology there. We could sense the

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gravitational wave signal of objects

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colliding in space. Yes, we're both in

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good form today.

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Andrew Dunkley: I think we are. 2015.

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14-9-2015. Spot on.

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Professor Fred Watson: Thanks. So that

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was, um, the first time. And, um, the

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track record of LIGO is incredible. You know,

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we celebrated the first detection and the

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second and the third, and then it got a bit

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routine and now they just churn them out.

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Um, but we've had black hole. Black hole

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collisions. We've had neutron star black hole

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Collisions. And we've had neutron star,

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neutron star collisions. And each

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of them gives a different sort of

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gravitational wave signature. And that's the

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critical thing, uh, that you can tell

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just by looking at the. It's almost like an

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acoustic wave, but it's on a

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microscopic scale because the vibrations

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are, uh, infinitesimally small,

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as we've discussed before. That's because

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space is so rigid. But these gravitational

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waves, as they pass through the Earth, they

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change the separation of two mirrors

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in what's called an interferometer.

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That's how LIGO works, with tiny, tiny

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differences. Uh, so, uh, those waves

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have a, uh. Because they come in, actually

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it's quite interesting. They come in at more

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or less acoustic, uh, frequency ranges. So

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if you amplify them up, you can hear it.

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Uh, it's a little bit more complicated than

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that, but you can actually, you know, it's

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within that wave band that we can hear

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things, even though it's sound that we, uh.

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And it's the vibration of space itself that,

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um, LIGO hears or sees.

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Um, so, uh, what

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has now happened is that,

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uh, uh, a group of. I think the

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group is based at the University of Miami,

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the researchers who've done this work,

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um, but they found a signature

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of a collision that involved,

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um, a star, or

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let me put it this way, an object which

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is a smaller mass than the

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Sun. Uh, now

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a black hole that small

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should not exist in conventional

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wisdom because the way we believe black holes

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are formed is by stars

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collapsing, uh, at the end of their

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lives, uh, as they

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detonate with a supernova explosion. The core

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collapses. The, the outer layers get

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shed into space, but the core collapses. Uh,

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and you've got a black hole, uh, an object

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with very, um, intense gravity

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because it basically collapses to a

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singularity, a point in space.

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Generic: Yeah.

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Professor Fred Watson: Uh, but, um, the conventional wisdom

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is that you need stars whose mass,

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whose initial mass is, you know, 5,

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6, 7, 8, 9, 10, perhaps times the mass of the

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Sun. That sort of level, usually

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10ish times the mass of the sun, is typically

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what you get. And so the black

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hole remnant that you get has a very similar

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mass to that. The outer envelope has been

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blown off. But most of the star's

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mass basically concentrates into the black

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hole. So finding a signature

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of an object that has

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less mass than the sun is

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inexplicable, uh, in

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conventional astrophysics. Um, it's

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too small. Uh, so,

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uh, what are the possibilities? And the thing

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that your mind, I'm sure, went straight

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towards, as did mine, is

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primordial black holes. And these are, uh,

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objects that were predicted by Stephen

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Hawking, um, back in the

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1970s. He proposed the existence

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of objects that

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basically turned into black holes

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in the aftermath of the Big Bang,

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where you've got pockets of

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subatomic material that could

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essentially collapse directly into a

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black hole without needing a, ah, star

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to go through, you know, to be formed and go

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through its, um, its lifetime and then

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collapse at the end of that, um, but all

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within, you know, the first, well,

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probably less than a second of the

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universe's existence. Uh, Hawking's theory

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suggests that these, uh, black holes

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were formed. Uh. Now

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nobody's proved anything yet. They've

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basically been

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theoretical entities. Uh, and,

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um, there's been no evidence to suggest

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that any of them exist.

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Until now. Yes, uh,

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where you have, um, a

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primordial. Perhaps a primordial black

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hole being detected with its

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collision, uh, that

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essentially can, uh, only be replicated

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if one of the objects has less than the mass

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of the sun. Uh, so where

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does that take us? It takes us

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straight back to dark matter.

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Because one of the things that was

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ruled out in the early days of

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our understanding of dark matter, this is

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back in the 19, uh, 70s, late

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1970s and 1980s, was, uh, black

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holes. Um, we ruled out black holes because

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we thought that they would all have masses

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much greater than the mass of the sun and

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that would reveal itself because if you

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did a survey of, uh, like,

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um, a survey that was done with

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the, um, what, what used to be called the

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50 inch telescope at Matt Stromlo Observatory

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here in Australia, this was in the 1980s.

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Um, that telescope, which is a storey in its

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own right, that we haven't time to go into

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now. Uh, but that telescope was used for a

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survey which was called macho. And that's

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because I remember that, yeah, MACHO

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is massive compact halo objects. And what it

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was looking for was evidence that the dark

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matter might be something solid rather than

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subatomic particles, which is actually the

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prevalent theory now. And by solid they

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meant, um, dwarf planets,

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rogue planets, uh, um, black

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holes, things that exist as

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a compact object that would distort

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the space around them. So that you'd get

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this, what's called gravitational

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microlensing effect. You'd get a

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magnification as this thing passed in front

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of a distant star. You get a magnification of

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the light from that star, which would be

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detectable by the MACHO experiment and the

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50 inch telescope, as it was called.

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Um, and while one or two

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of these gravitational microlensing events

273
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was found. It was nowhere near enough

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to be able to use black holes as

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the basis for dark matter, which is why

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interest was lost in the idea that this is

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solid particles and the whole idea of

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it being WIMPs, the opposite of machos,

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WIMPs, weakly interactive massive particles.

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That's where that all emerged and that's

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where we are now. Um, most of the

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world of physics believes that there are some

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atomic particles that account for

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the dark matter, which of course reveals

285
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itself by its gravitational influence either

286
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on the rotation of galaxies or the,

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um, the movement of galaxies in clusters or

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indeed the structure of the universe at

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large. It seems to suggest it's there. So

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the finding of a primordial, of

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a less than 1 solar mass black

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hole, which would have to be probably a

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primordial black hole, uh, opens up that

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possibility again. Because if you can find

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one, there might be gazillions of

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them out there.

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And, uh, we might be, you know,

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misinterpreting what we're looking for. If

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we're not looking for small, uh, black holes,

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we're actually looking for subatomic

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particles that maybe don't exist. We have at

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least one listener to space nuts, uh,

303
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whose name is Pete, uh,

304
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who doesn't think they exist because he's

305
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researching one of the alternative

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theories, the MOND theory, modified Newtonian

307
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dynamics.

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Andrew Dunkley: Yeah, it's really interesting, but, um,

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it's still kind of a theory, isn't

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it? I know they've made this detection using

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00:13:28.570 --> 00:13:31.490
ligo, but they have to confirm it

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00:13:31.730 --> 00:13:34.050
by making another detection, don't they?

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Professor Fred Watson: Uh, yes, you'd want to see more

314
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and you'd kind of want to start seeing

315
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evidence of other kinds. For example, if

316
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you revisited the MACHO experiment and look

317
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for the gravitation, the um,

318
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gravitational macro ending signal of

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tiny black holes that were created in the Big

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Bang, then, uh, that might confirm

321
00:13:57.510 --> 00:14:00.370
this and give the, um,

322
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idea of primordial black holes

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00:14:04.110 --> 00:14:06.830
being the dark matter. It would give it a

324
00:14:06.830 --> 00:14:08.990
much more solid observational basis.

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Andrew Dunkley: Yeah, well, it stands to reason that, uh,

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if Stephen Hawking says so, it's probably

327
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true. Um, but,

328
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uh, it wasn't so long ago that you and I were

329
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talking about black holes and we were saying,

330
00:14:23.040 --> 00:14:25.000
look, there's super massive ones and there's

331
00:14:25.000 --> 00:14:27.000
small ones, but there's no in between ones.

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00:14:27.160 --> 00:14:29.240
And I think within a week or two of us having

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00:14:29.240 --> 00:14:31.680
that conversation, they found one and now

334
00:14:31.680 --> 00:14:33.880
they've found a bunch. So

335
00:14:34.600 --> 00:14:37.480
now we're going even smaller and

336
00:14:37.480 --> 00:14:40.360
it could reveal a heck of a lot, um, maybe

337
00:14:40.360 --> 00:14:42.120
solve some of those Mysteries that we've been

338
00:14:42.120 --> 00:14:45.080
talking about forever and getting bombarded

339
00:14:45.080 --> 00:14:46.520
with in terms of questions.

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Professor Fred Watson: Yes, which is just as well because. Oh

341
00:14:50.040 --> 00:14:51.800
yeah, keeps us, keeps us going.

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Andrew Dunkley: It does indeed. Ah, fabulous storey. If

343
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you'd like to read about it, it's at uh,

344
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space daily.com. uh,

345
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and um, yeah it's a really fascinating

346
00:15:02.599 --> 00:15:05.480
article about a uh, sub solar black hole.

347
00:15:06.520 --> 00:15:09.280
Just uh, change the dark matter debate is the

348
00:15:09.280 --> 00:15:12.280
title of the article. Uh, it is

349
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isn't it? It's a really great read.

350
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This is Space Nuts with Andrew Dunkley and

351
00:15:16.570 --> 00:15:18.170
Professor Fred Watson Watson.

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Generic: Roger, you're lots three here.

353
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Professor Fred Watson: Also Space Nuts.

354
00:15:23.850 --> 00:15:26.010
Andrew Dunkley: Our uh, next storey Fred Watson is just as

355
00:15:26.010 --> 00:15:29.010
fascinating because they have done uh, a bit

356
00:15:29.010 --> 00:15:31.530
of an analysis of chemical analysis on

357
00:15:31.690 --> 00:15:34.650
a planet, an ultra hot Jupiter

358
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and they have made some extraordinary

359
00:15:37.610 --> 00:15:38.410
discoveries.

360
00:15:39.930 --> 00:15:42.740
Professor Fred Watson: Yeah, they're, these are um, they're

361
00:15:42.740 --> 00:15:43.980
great discoveries because

362
00:15:45.740 --> 00:15:47.900
the technology and the techniques required

363
00:15:48.460 --> 00:15:51.300
to make these are uh, phenomenal in their

364
00:15:51.300 --> 00:15:54.300
own right. But um, in a way

365
00:15:54.940 --> 00:15:57.740
this discovery should set us all sort of

366
00:15:57.740 --> 00:15:59.660
yawning with. Well that's what we thought.

367
00:16:00.440 --> 00:16:02.860
Andrew Dunkley: Um, well the previous storey probably too,

368
00:16:02.860 --> 00:16:05.740
but it's too big not to make you go

369
00:16:05.820 --> 00:16:06.300
wow.

370
00:16:07.110 --> 00:16:09.710
Professor Fred Watson: Yeah, yeah, this goes wow too but for

371
00:16:09.710 --> 00:16:12.550
slightly different reasons. So um, when,

372
00:16:13.830 --> 00:16:16.510
when astrophysicists think about the planets

373
00:16:16.510 --> 00:16:19.190
going around other stars, they

374
00:16:19.670 --> 00:16:22.150
basically make assumptions about

375
00:16:22.549 --> 00:16:25.270
the raw materials that those planets

376
00:16:25.510 --> 00:16:28.230
were made of. And, and their

377
00:16:28.230 --> 00:16:31.190
assumptions come from measurements

378
00:16:31.350 --> 00:16:34.030
of the uh, heavy

379
00:16:34.030 --> 00:16:36.990
element content in the parent

380
00:16:36.990 --> 00:16:39.780
stars. So if you, if uh,

381
00:16:39.950 --> 00:16:42.510
you observe a star, uh, you can use

382
00:16:42.510 --> 00:16:44.950
spectroscopy to look at the

383
00:16:45.350 --> 00:16:47.990
distribution of elements in its

384
00:16:47.990 --> 00:16:49.990
atmosphere. Sometimes molecules as well, if

385
00:16:49.990 --> 00:16:52.590
it's a cool star. But usually it's just the

386
00:16:52.590 --> 00:16:55.070
atomic elements. And uh, this goes back to

387
00:16:55.070 --> 00:16:57.950
the beginnings of astronomical spectroscopy.

388
00:16:57.950 --> 00:16:59.780
The idea of you know, splitting the light up

389
00:16:59.780 --> 00:17:01.540
into its rainbow of colours and looking for

390
00:17:01.540 --> 00:17:03.740
the signature of different elements in it.

391
00:17:03.740 --> 00:17:05.980
That goes back to 1869 I think,

392
00:17:06.620 --> 00:17:09.080
um, might even have been 59 when um,

393
00:17:09.420 --> 00:17:12.220
William Huggins made the first

394
00:17:12.220 --> 00:17:14.380
observations of the spectra of stars.

395
00:17:15.040 --> 00:17:17.420
Um, so Huggins

396
00:17:18.460 --> 00:17:20.860
basically said, well we know what the

397
00:17:20.860 --> 00:17:23.500
signature of elements is on Earth. In fact

398
00:17:23.500 --> 00:17:26.260
some work done by Kirchhoff and Bunsen before

399
00:17:26.260 --> 00:17:28.620
that had worked out what the elements were

400
00:17:28.620 --> 00:17:31.600
present in the sun were. Uh, and Huggins

401
00:17:31.600 --> 00:17:33.240
did it. You're going to cheque up on me here.

402
00:17:33.240 --> 00:17:35.960
Is it 1869 or 1859?

403
00:17:36.080 --> 00:17:36.910
Andrew Dunkley: Um,

404
00:17:38.120 --> 00:17:41.000
186. Well there's a few things

405
00:17:41.080 --> 00:17:43.480
on the list that involved it, but

406
00:17:43.560 --> 00:17:46.040
1860s is generally the accepted

407
00:17:47.240 --> 00:17:50.200
time frame. Um, yeah,

408
00:17:50.360 --> 00:17:53.200
I think he used uh, Doppler shift to measure

409
00:17:53.200 --> 00:17:55.520
the radial velocity of Sirius in

410
00:17:55.520 --> 00:17:57.880
1868. And uh, he

411
00:17:57.880 --> 00:18:00.280
specifically identified absorption lines in

412
00:18:00.280 --> 00:18:03.020
stellar spectra, including veg in

413
00:18:03.020 --> 00:18:04.980
1863 and 1864.

414
00:18:05.460 --> 00:18:08.100
Professor Fred Watson: Yeah, yeah. So, so that, that's

415
00:18:08.420 --> 00:18:10.780
not the right time. That's when we've, that's

416
00:18:10.780 --> 00:18:13.620
how long we've known about the elements that

417
00:18:13.620 --> 00:18:16.140
make up the atmospheres of stars. Most of it

418
00:18:16.140 --> 00:18:18.500
is hydrogen. Um, and,

419
00:18:19.060 --> 00:18:22.060
but that's what basically what is

420
00:18:22.060 --> 00:18:24.820
the raw material or the fuel that makes stars

421
00:18:24.820 --> 00:18:27.660
burn or they don't burn but they, they

422
00:18:27.660 --> 00:18:29.860
have nuclear fusion which keeps them going.

423
00:18:30.360 --> 00:18:33.350
Um, but uh, it's the sprinkling

424
00:18:33.350 --> 00:18:36.300
of the other elements that uh,

425
00:18:36.300 --> 00:18:38.230
make up the atmosphere of the star and they

426
00:18:38.230 --> 00:18:40.790
vary depending on the temperature and

427
00:18:41.190 --> 00:18:43.670
category and age of the star. We measure

428
00:18:44.070 --> 00:18:46.909
something called metallicity. And you and I

429
00:18:46.909 --> 00:18:49.270
have chuckled before about the fact that

430
00:18:49.780 --> 00:18:52.630
uh, oxygen's astronomy. Yeah.

431
00:18:52.630 --> 00:18:55.350
Astronomers call everything heavier than

432
00:18:55.480 --> 00:18:57.510
uh, either hydrogen or helium. Everything

433
00:18:57.510 --> 00:18:59.990
else is a metal. Including oxygen. That's

434
00:18:59.990 --> 00:19:02.320
right. And neon and things like that.

435
00:19:03.200 --> 00:19:05.680
Um, it's just a term that came about in

436
00:19:05.680 --> 00:19:07.600
probably about the same time as Huggins was

437
00:19:07.600 --> 00:19:10.120
working on it back in the 19th century.

438
00:19:10.120 --> 00:19:12.880
Anyway, um, the metallicity is a measurement

439
00:19:12.880 --> 00:19:15.760
of the richness in terms of the chemical

440
00:19:15.760 --> 00:19:17.800
elements that are in the atmosphere of a

441
00:19:17.800 --> 00:19:20.560
star. And so the

442
00:19:20.560 --> 00:19:23.520
assumption has always been that if

443
00:19:23.600 --> 00:19:26.600
you know, a star generates its own

444
00:19:26.600 --> 00:19:28.920
solar system and that process takes place

445
00:19:28.920 --> 00:19:31.800
simultaneously, the cloud of gas and

446
00:19:31.800 --> 00:19:34.020
dust collapses into a star, uh,

447
00:19:34.480 --> 00:19:37.000
which eventually heats up to the extent that

448
00:19:37.000 --> 00:19:39.960
it. Nuclear fusion occurs as

449
00:19:39.960 --> 00:19:42.760
it is with the sun. Uh, but the swirling

450
00:19:42.760 --> 00:19:45.320
disc of material around it called the uh, the

451
00:19:45.320 --> 00:19:48.200
protoplanetary disc, that stuff is where the

452
00:19:48.200 --> 00:19:50.480
planets form. But the planets are basically

453
00:19:50.480 --> 00:19:52.880
made of the same stuff as the star is.

454
00:19:53.200 --> 00:19:55.560
That's the bottom line. So that's always been

455
00:19:55.560 --> 00:19:57.520
the assumption that if we're observing

456
00:19:57.520 --> 00:20:00.040
planets around other stars they must have the

457
00:20:00.040 --> 00:20:02.900
same content. And that's in

458
00:20:02.900 --> 00:20:04.380
terms of whether these planets are going to

459
00:20:04.380 --> 00:20:06.380
be rocky or not. If you got lots of silicate

460
00:20:06.620 --> 00:20:09.060
material, uh, in it, that would have come

461
00:20:09.060 --> 00:20:11.540
from the silicon in the atmosphere of the

462
00:20:11.540 --> 00:20:14.380
star. So all these things are inter layered.

463
00:20:14.950 --> 00:20:17.820
Um, so that assumption has never been tested

464
00:20:17.900 --> 00:20:20.900
until now. And that's why, that's

465
00:20:20.900 --> 00:20:23.710
why this is a wow storey, uh, because uh,

466
00:20:23.710 --> 00:20:25.900
this uh, is some observations

467
00:20:26.570 --> 00:20:29.500
uh, of exactly as you've said, um, super

468
00:20:29.500 --> 00:20:32.190
hot Jupiter. Uh, it

469
00:20:32.190 --> 00:20:35.190
is uh, or an ultra hot Jupiter is

470
00:20:35.190 --> 00:20:37.510
the technical term usually um,

471
00:20:37.790 --> 00:20:40.510
abbreviated to uhj. So

472
00:20:40.510 --> 00:20:42.870
uh, that's a great new term for us. An

473
00:20:42.870 --> 00:20:45.789
acronym, an urge. An ultra hot

474
00:20:45.789 --> 00:20:48.630
Jupiter. Uh, it's about 320 light

475
00:20:48.630 --> 00:20:50.720
years away. It is called WASP

476
00:20:50.900 --> 00:20:53.830
189B. WASP is I think the wide angle

477
00:20:53.830 --> 00:20:56.590
search for planets if I remember rightly. Uh,

478
00:20:56.590 --> 00:20:59.230
and um, it's um, because it's an ultra

479
00:20:59.850 --> 00:21:02.490
Jupiter, um, the

480
00:21:02.490 --> 00:21:04.890
temperature of its atmosphere is

481
00:21:05.690 --> 00:21:08.530
ridiculously hot. Uh, you know it's measured

482
00:21:08.530 --> 00:21:11.370
in thousands of degrees and that means

483
00:21:11.690 --> 00:21:14.010
that the materials within it

484
00:21:14.550 --> 00:21:17.370
ah, are vaporised, particularly

485
00:21:17.610 --> 00:21:20.210
the rock forming elements like

486
00:21:20.210 --> 00:21:22.650
magnesium, silicon, iron

487
00:21:23.370 --> 00:21:25.970
and um, probably calcium and a few other

488
00:21:25.970 --> 00:21:28.170
things as well. They're the things that make

489
00:21:28.170 --> 00:21:31.050
up um, rocks if they're

490
00:21:31.050 --> 00:21:33.930
cold, uh, but

491
00:21:33.930 --> 00:21:36.570
this one has them in its atmosphere. And the

492
00:21:36.570 --> 00:21:39.450
key point about this storey which

493
00:21:39.450 --> 00:21:42.450
was led uh, from Arizona State University

494
00:21:42.930 --> 00:21:44.769
along with an international team of

495
00:21:44.769 --> 00:21:47.170
astronomers. The key point is

496
00:21:47.490 --> 00:21:50.450
that the chemical makeup

497
00:21:50.770 --> 00:21:53.650
of WASP18B exactly

498
00:21:53.650 --> 00:21:56.600
matches its parent star. Uh, um,

499
00:21:56.600 --> 00:21:59.540
and that is really you know, that's a kind of

500
00:21:59.540 --> 00:22:02.420
smoking gun that tells us that we're on the

501
00:22:02.420 --> 00:22:05.220
right track when we uh, when

502
00:22:05.220 --> 00:22:08.060
we make the assumption that the material

503
00:22:08.380 --> 00:22:11.180
in a planet around the other star,

504
00:22:11.180 --> 00:22:13.180
the material of which that planet is made

505
00:22:13.420 --> 00:22:15.940
will have the same, what we call chemical

506
00:22:15.940 --> 00:22:18.820
abundances, the ratios of the, of

507
00:22:18.820 --> 00:22:21.100
the different chemical elements to its parent

508
00:22:21.100 --> 00:22:23.740
star. Which is important

509
00:22:23.820 --> 00:22:25.660
information because it means we're on the

510
00:22:25.660 --> 00:22:26.700
right track basically.

511
00:22:27.020 --> 00:22:28.900
Andrew Dunkley: I'm going to ask the obvious dumb question

512
00:22:28.900 --> 00:22:31.580
here though. Um, so we've discovered this

513
00:22:32.380 --> 00:22:34.620
thousands um, of light years away with WASP

514
00:22:34.620 --> 00:22:37.500
189B. Why didn't we know

515
00:22:37.500 --> 00:22:40.220
that in regard to our own sun and Earth?

516
00:22:41.650 --> 00:22:44.060
Professor Fred Watson: Uh, yeah, well we do, um, okay,

517
00:22:44.220 --> 00:22:46.900
that's a good question. We do, um, and

518
00:22:46.900 --> 00:22:49.020
so but it's never been tested for

519
00:22:50.220 --> 00:22:52.180
what you might call the general case. And an

520
00:22:52.180 --> 00:22:54.850
ultra hot Jupiter is so different from

521
00:22:54.850 --> 00:22:57.330
anything in the solar system that it's

522
00:22:57.410 --> 00:23:00.290
reassuring that you get the same answer

523
00:23:00.290 --> 00:23:03.050
from that as we do from our own solar

524
00:23:03.050 --> 00:23:04.450
system. That's a great question.

525
00:23:04.530 --> 00:23:07.090
Andrew Dunkley: Yeah. Uh, this um, particular

526
00:23:07.170 --> 00:23:09.929
planet is uh, double the size of

527
00:23:09.929 --> 00:23:12.530
Jupiter. It's 1.99

528
00:23:12.610 --> 00:23:15.530
planetary masses. Um, when you compare

529
00:23:15.530 --> 00:23:18.530
it to Jupiter um, it was only

530
00:23:18.530 --> 00:23:21.420
discovered five, six years ago.

531
00:23:21.740 --> 00:23:24.540
So um, it's a new one. Um,

532
00:23:24.860 --> 00:23:27.740
but it's um, 1.619 times

533
00:23:28.220 --> 00:23:30.620
bigger than Jupiter in terms of its radius.

534
00:23:31.020 --> 00:23:33.900
So it's a big, it's a monster, isn't it?

535
00:23:34.580 --> 00:23:35.820
Professor Fred Watson: Uh, yes it is.

536
00:23:37.900 --> 00:23:40.540
Some of the planets that we find orbiting

537
00:23:40.540 --> 00:23:42.140
other stars are pretty crazy.

538
00:23:42.220 --> 00:23:44.940
Andrew Dunkley: I said thousands of light years. It's 320.

539
00:23:44.940 --> 00:23:46.710
Professor Fred Watson: Yes, 300, that's right.

540
00:23:47.590 --> 00:23:49.110
That's okay, we'll let you off that.

541
00:23:49.110 --> 00:23:49.670
Andrew Dunkley: Yeah,

542
00:23:51.910 --> 00:23:54.870
I'm not quite with it today. I

543
00:23:54.870 --> 00:23:56.190
don't know how that's different from any

544
00:23:56.190 --> 00:23:56.750
other day.

545
00:23:56.750 --> 00:23:59.670
Professor Fred Watson: But um, well funnily enough neither

546
00:23:59.670 --> 00:24:02.550
am I because I can only hear through one ear

547
00:24:02.550 --> 00:24:05.470
at the moment. Uh, I

548
00:24:05.470 --> 00:24:06.870
hate that. Yeah.

549
00:24:06.870 --> 00:24:09.230
Andrew Dunkley: One of the pitfalls of radio is you, you

550
00:24:09.230 --> 00:24:11.390
build up a lot of earwax fast and if you

551
00:24:11.390 --> 00:24:14.310
don't keep up up cleaning you go

552
00:24:14.310 --> 00:24:17.230
deaf and then you have to go to the doctor

553
00:24:17.230 --> 00:24:19.230
and get syringed. It's not very pleasant.

554
00:24:20.010 --> 00:24:22.070
Uh, I'm sure people really wanted to hear

555
00:24:22.070 --> 00:24:22.350
that.

556
00:24:22.590 --> 00:24:23.390
Professor Fred Watson: Yes, that's right.

557
00:24:23.390 --> 00:24:25.990
I'm thinking that. But you know the stuff

558
00:24:25.990 --> 00:24:28.030
that comes out of your ear is, has the same

559
00:24:28.430 --> 00:24:31.190
chemical mix as the stuff that's

560
00:24:31.190 --> 00:24:34.030
inside the sun in some remote way.

561
00:24:34.110 --> 00:24:36.430
So I'm sure there is a link with astronomy.

562
00:24:37.230 --> 00:24:38.140
Oh gosh.

563
00:24:38.250 --> 00:24:39.970
Andrew Dunkley: Um, the article, if you want to read it

564
00:24:39.970 --> 00:24:42.490
it's@scitechdaily.com where you can read the

565
00:24:42.490 --> 00:24:45.090
paper in Nature Communications.

566
00:24:45.570 --> 00:24:47.930
This is Space Nuts with Andrew Dunkley and

567
00:24:47.930 --> 00:24:49.570
Professor Fred Watson Watson.

568
00:24:51.730 --> 00:24:53.650
We choose to go to the Moon

569
00:24:53.650 --> 00:24:55.450
Professor Fred Watson: in this decade and do the other

570
00:24:55.450 --> 00:24:58.330
Andrew Dunkley: things not because they are easy but

571
00:24:58.330 --> 00:25:00.370
because they are hard Space nuts.

572
00:25:01.490 --> 00:25:03.610
And we are going to the Moon right now

573
00:25:03.610 --> 00:25:05.970
because something happened. It got hit by a

574
00:25:05.970 --> 00:25:08.690
big rock and it's

575
00:25:08.690 --> 00:25:11.270
created massive

576
00:25:11.270 --> 00:25:13.110
crater. I mean this is a, this is a very

577
00:25:13.110 --> 00:25:14.550
recent development Fred Watson.

578
00:25:15.430 --> 00:25:18.390
Professor Fred Watson: Yes it is. Uh, it's um, one

579
00:25:18.390 --> 00:25:20.910
that comes uh, about or a discovery that

580
00:25:20.910 --> 00:25:23.170
comes about because of our ability uh,

581
00:25:23.990 --> 00:25:26.570
to detect changes on the Moon given ah,

582
00:25:26.870 --> 00:25:29.500
that the Lunar Reconnaissance Orbiter

583
00:25:29.500 --> 00:25:31.830
ah, uh, is

584
00:25:32.310 --> 00:25:35.230
still photographing the lunar surface and

585
00:25:35.230 --> 00:25:36.950
it's been doing that. I can't remember when

586
00:25:37.150 --> 00:25:39.900
Lunar Reconnaissance Orbiter was uh,

587
00:25:40.590 --> 00:25:42.390
commissioned, uh, when it came on stream, but

588
00:25:42.390 --> 00:25:44.150
it's quite a few years ago. It's probably a

589
00:25:44.150 --> 00:25:46.550
decade ago now. I'm sure you'll tell me in a

590
00:25:46.550 --> 00:25:49.310
minute. Um, LRO

591
00:25:49.310 --> 00:25:52.030
as it's called. And because it's doing this

592
00:25:52.030 --> 00:25:54.830
sort of continuous survey we can

593
00:25:54.830 --> 00:25:57.390
see when something changes. And

594
00:25:57.790 --> 00:26:00.710
in the late northern uh hemisphere spring

595
00:26:00.710 --> 00:26:03.690
of 2024 uh something did

596
00:26:03.690 --> 00:26:06.050
change. Uh, a rock, um,

597
00:26:06.690 --> 00:26:08.850
probably several metres

598
00:26:09.410 --> 00:26:12.250
in diameter, maybe even tens of

599
00:26:12.250 --> 00:26:15.210
metres, um, uh, hit the

600
00:26:15.210 --> 00:26:17.170
moon and produced a crater

601
00:26:17.490 --> 00:26:20.370
225 metres across uh

602
00:26:20.530 --> 00:26:23.380
on the surface of the Moon. Um,

603
00:26:23.380 --> 00:26:26.210
and that is something that

604
00:26:26.210 --> 00:26:28.770
we know happens. We expect this to happen

605
00:26:28.770 --> 00:26:31.170
because we get bombardment by

606
00:26:31.250 --> 00:26:33.650
objects that size of the Earth's atmosphere.

607
00:26:33.650 --> 00:26:35.150
They're relatively, relatively rare.

608
00:26:35.150 --> 00:26:38.150
Something like um, you know it will

609
00:26:38.150 --> 00:26:41.110
be once every 30 years or so for a 10

610
00:26:41.110 --> 00:26:43.910
metre object to uh, hit the

611
00:26:43.910 --> 00:26:45.590
Earth's atmosphere. Probably explode in the

612
00:26:45.590 --> 00:26:47.430
Earth's atmosphere. But with the Moon not

613
00:26:47.430 --> 00:26:49.630
having an Atmosphere go straight down to the

614
00:26:49.630 --> 00:26:51.110
surface and what do you get? You get a

615
00:26:51.110 --> 00:26:53.550
crater. Um, and it's

616
00:26:53.790 --> 00:26:56.590
apparently, uh, this is by far

617
00:26:56.670 --> 00:26:59.550
the largest new crater that's

618
00:26:59.550 --> 00:27:01.630
been found during the lifetime of the Lunar

619
00:27:01.630 --> 00:27:03.390
Reconnaissance Orbiter Mission. The last

620
00:27:03.390 --> 00:27:06.110
record was 70 metres across. This one's

621
00:27:06.340 --> 00:27:09.290
much more. Yes, and suggests, um,

622
00:27:09.860 --> 00:27:12.820
that, that this is a much rarer object. And

623
00:27:12.820 --> 00:27:14.820
one of the reasons I, I like this storey,

624
00:27:15.060 --> 00:27:17.860
Andrew, is that it has echoes of something

625
00:27:17.860 --> 00:27:20.020
we've just heard about this last week.

626
00:27:20.340 --> 00:27:23.060
Andrew Dunkley: The meteorite flashes that the

627
00:27:23.060 --> 00:27:24.180
Artemis crew saw.

628
00:27:24.180 --> 00:27:25.380
Professor Fred Watson: Yeah, exactly.

629
00:27:25.380 --> 00:27:26.980
Andrew Dunkley: They saw things hitting the moon.

630
00:27:27.540 --> 00:27:30.020
Professor Fred Watson: Yes, indeed. And they saw these flashes that,

631
00:27:30.050 --> 00:27:32.350
um. And that's what they are. And so, um,

632
00:27:32.820 --> 00:27:34.820
this one would have been a very big flash.

633
00:27:34.910 --> 00:27:36.860
Uh, I'm not sure whereabouts on the moon it

634
00:27:36.860 --> 00:27:39.270
is as to was on the Earth, uh,

635
00:27:39.480 --> 00:27:42.400
facing side of the moon or not. Uh, but

636
00:27:42.480 --> 00:27:45.040
it made, certainly made. It would have made

637
00:27:45.040 --> 00:27:47.520
quite a bright flash. Uh, and

638
00:27:47.760 --> 00:27:50.480
you know, we've known for more than, well,

639
00:27:50.480 --> 00:27:53.480
60 years, uh, that these things do happen.

640
00:27:53.480 --> 00:27:55.280
It took a while before people worked out

641
00:27:55.280 --> 00:27:58.280
that, uh, and before the Apollo era, that

642
00:27:58.280 --> 00:27:59.920
people worked out that these were caused by

643
00:27:59.920 --> 00:28:02.280
impacts rather than, uh, rather than by

644
00:28:02.280 --> 00:28:04.280
volcanic activity. I remember old Patrick

645
00:28:04.280 --> 00:28:06.810
Moore, the doyen of space communicators in,

646
00:28:06.960 --> 00:28:09.760
in the uk. I, um, remember him.

647
00:28:10.160 --> 00:28:12.040
In fact, one of the things he did research on

648
00:28:12.040 --> 00:28:14.520
was what he called TLES, transient lunar

649
00:28:14.520 --> 00:28:17.480
events. But nobody knew back in the 40s and

650
00:28:17.480 --> 00:28:20.480
50s whether these were volcanic eruptions or,

651
00:28:20.770 --> 00:28:23.680
uh, meteorite impacts. Now we know and,

652
00:28:23.790 --> 00:28:25.760
um, we've almost seen them happen before our

653
00:28:25.760 --> 00:28:28.560
eyes with this newly discovered crater.

654
00:28:28.800 --> 00:28:31.680
Andrew Dunkley: Yeah, and It's a whopper, 225 metres

655
00:28:32.160 --> 00:28:34.230
across. So, um.

656
00:28:35.100 --> 00:28:38.060
Yeah, and I suppose you could have a guess at

657
00:28:38.060 --> 00:28:39.980
how big the rock that hit it was, what, 10

658
00:28:39.980 --> 00:28:40.700
metres, you think?

659
00:28:40.700 --> 00:28:42.780
Professor Fred Watson: Maybe something. Yeah, yeah, that sort of

660
00:28:42.780 --> 00:28:43.020
order.

661
00:28:43.020 --> 00:28:44.860
Andrew Dunkley: And, and would that rock still be on the moon

662
00:28:44.860 --> 00:28:46.660
or did it get obliterated? Because it gets

663
00:28:46.660 --> 00:28:48.540
really hot, the impact, it just melts

664
00:28:48.540 --> 00:28:50.300
everything and then it freezes instantly or

665
00:28:50.300 --> 00:28:50.980
something, doesn't it?

666
00:28:50.980 --> 00:28:53.060
Professor Fred Watson: That's, that's right. Vaporised. It would

667
00:28:53.060 --> 00:28:54.980
have been vaporised. Right. The energy of

668
00:28:54.980 --> 00:28:57.700
impact, um, you know, this is coming in at 30

669
00:28:57.700 --> 00:28:59.740
or 40 kilometres per second.

670
00:29:00.450 --> 00:29:02.700
Um, and when it hits rock, I mean, we know

671
00:29:02.700 --> 00:29:05.310
from simulations of these meteorites,

672
00:29:05.690 --> 00:29:08.580
uh, small asteroid impact on Earth, that

673
00:29:08.580 --> 00:29:10.310
the crust, uh,

674
00:29:11.140 --> 00:29:14.140
turns literally into a liquid, uh, behaves

675
00:29:14.140 --> 00:29:16.660
like a liquid. Um, I've got a simulation that

676
00:29:16.660 --> 00:29:19.420
I showed on yesterday to a class of physics

677
00:29:19.420 --> 00:29:21.910
students at the University of Wollongong, uh,

678
00:29:22.590 --> 00:29:25.500
um, online. Um, it's a Simulation that shows

679
00:29:25.500 --> 00:29:26.860
what would have happened to the Earth's

680
00:29:26.860 --> 00:29:29.700
surface with the, uh, 10 kilometre

681
00:29:29.700 --> 00:29:31.300
diameter asteroid that took out the

682
00:29:31.300 --> 00:29:34.000
dinosaurs. And it. In, you know,

683
00:29:34.000 --> 00:29:35.760
you got within the first

684
00:29:36.640 --> 00:29:39.360
60 seconds, you've, you've got both

685
00:29:39.760 --> 00:29:42.480
a hole 20 kilometres deep

686
00:29:42.640 --> 00:29:45.360
and a mountain range 20 kilometres high

687
00:29:45.360 --> 00:29:48.200
being formed within the first few seconds.

688
00:29:48.200 --> 00:29:49.360
Andrew Dunkley: Just mind blowing.

689
00:29:49.760 --> 00:29:52.560
Professor Fred Watson: Absolutely. And so, um, yes,

690
00:29:52.560 --> 00:29:54.960
this, this new crater, in fact one of the

691
00:29:55.200 --> 00:29:58.120
salient points about it is it's quite, it

692
00:29:58.120 --> 00:30:00.880
is actually quite deep. It's 43 metres deep.

693
00:30:01.320 --> 00:30:04.200
Um, the, there's a nice article about this in

694
00:30:04.200 --> 00:30:07.080
Universe Today that makes the point that

695
00:30:07.800 --> 00:30:09.760
40, um, three metres deep, that means the

696
00:30:09.760 --> 00:30:12.440
walls of the crater would be steep enough

697
00:30:12.440 --> 00:30:15.400
that you'd struggle to stand on them. Um, and

698
00:30:15.400 --> 00:30:18.280
so, um, uh, it's got, uh, yes,

699
00:30:19.080 --> 00:30:21.080
quite a significantly deep object.

700
00:30:21.640 --> 00:30:24.480
Andrew Dunkley: Indeed it is, yes. Um, and as

701
00:30:24.480 --> 00:30:25.560
Fred Watson said, you can read about

702
00:30:25.560 --> 00:30:28.320
that@universetoday.com and for the

703
00:30:28.320 --> 00:30:31.040
record, uh, the, uh, Lunar

704
00:30:31.040 --> 00:30:33.520
Reconnaissance Orbiter started observing the

705
00:30:33.520 --> 00:30:35.700
moon close in 2009.

706
00:30:36.660 --> 00:30:38.980
Professor Fred Watson: Really? 16, 17 years.

707
00:30:39.140 --> 00:30:39.540
Andrew Dunkley: Yeah.

708
00:30:39.540 --> 00:30:40.180
Professor Fred Watson: Fantastic.

709
00:30:40.420 --> 00:30:41.300
Andrew Dunkley: It's impressive.

710
00:30:42.740 --> 00:30:45.300
All right, uh, that brings us to the end of

711
00:30:45.300 --> 00:30:47.020
the programme. Fred Watson, thank you so

712
00:30:47.020 --> 00:30:47.300
much.

713
00:30:48.580 --> 00:30:50.540
Professor Fred Watson: Time flies when you're having fun does,

714
00:30:50.540 --> 00:30:51.140
doesn't it?

715
00:30:52.420 --> 00:30:54.300
Andrew Dunkley: We'll be back. We'll be back and we'll see

716
00:30:54.300 --> 00:30:54.740
you then.

717
00:30:55.380 --> 00:30:56.820
Professor Fred Watson: Sounds great. Thanks, Andrew.

718
00:30:56.820 --> 00:30:58.140
Andrew Dunkley: Thank you, Fred Watson. Professor Fred Watson

719
00:30:58.140 --> 00:31:00.100
Watson, astronomer at large. Don't forget to

720
00:31:00.100 --> 00:31:01.940
visit us online while you're out and about or

721
00:31:01.940 --> 00:31:03.940
listening to us, um, at our website,

722
00:31:03.940 --> 00:31:06.580
spacenutspodcast.com spacenuts

723
00:31:06.580 --> 00:31:09.540
IO the AMA tab is there to

724
00:31:09.620 --> 00:31:12.460
ask us anything. It says ask me anything,

725
00:31:12.460 --> 00:31:15.380
but don't bother asking me, but ask, um, me

726
00:31:15.380 --> 00:31:17.620
anything. And, uh, you can send messages.

727
00:31:18.180 --> 00:31:20.900
You can, um, uh, send

728
00:31:20.900 --> 00:31:23.420
questions, audio or text. Don't forget to

729
00:31:23.420 --> 00:31:25.340
tell us who you are and where you're from and

730
00:31:25.340 --> 00:31:28.100
we'll fix them up, uh, in our Q and A

731
00:31:28.100 --> 00:31:30.660
episodes. And, uh, while you're there, have a

732
00:31:30.660 --> 00:31:32.700
look around. Visit the Space Nuts shop.

733
00:31:32.700 --> 00:31:34.960
There's lots of goodies in there. It's coming

734
00:31:34.960 --> 00:31:37.360
on to winter in Australia, so you might need

735
00:31:37.360 --> 00:31:39.400
yourself a hoodie. I mean, you can look like

736
00:31:39.400 --> 00:31:41.960
a thug and be an astronomer at the same time.

737
00:31:42.840 --> 00:31:44.930
Fred Watson does. And, um.

738
00:31:47.560 --> 00:31:48.320
Damn, I should.

739
00:31:48.320 --> 00:31:48.680
Professor Fred Watson: No.

740
00:31:48.680 --> 00:31:51.360
Andrew Dunkley: I usually have a crack at Huw, but he's not

741
00:31:51.360 --> 00:31:53.680
an astronomer. Um, but yeah. And thanks to

742
00:31:53.680 --> 00:31:55.360
Huw in the studio, who couldn't be with us

743
00:31:55.360 --> 00:31:57.600
today, he's once again in police custody

744
00:31:57.600 --> 00:32:00.600
because they found a giant. A giant,

745
00:32:01.240 --> 00:32:03.800
I'm saying, slingshot in his backyard, aimed

746
00:32:03.800 --> 00:32:06.360
at the moon. Oh. Oh,

747
00:32:06.360 --> 00:32:08.960
yeah. And from me, Andrew Dunkley. Thanks for

748
00:32:08.960 --> 00:32:10.160
your company. We'll see you on the next

749
00:32:10.160 --> 00:32:12.040
episode of Space Nuts. Bye. Bye.

750
00:32:13.400 --> 00:32:15.600
You've been listening to the Space Nuts

751
00:32:15.600 --> 00:32:18.600
podcast, available at

752
00:32:18.600 --> 00:32:20.520
Apple Podcasts, Spotify,

753
00:32:20.760 --> 00:32:23.520
iHeartRadio or your favourite podcast

754
00:32:23.520 --> 00:32:25.280
player. You can also stream on

755
00:32:25.280 --> 00:32:27.520
demand@bytes.com this

756
00:32:27.520 --> 00:32:29.880
Professor Fred Watson: has been another quality podcast production

757
00:32:29.880 --> 00:32:31.330
from bytes.com.