Moon Mysteries, Hubble Tension & the Kuiper Belt's Triple Surprise

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Professor Fred Watson: Hello again.

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Andrew Dunkley: Andrew Dunkley here from Space Nuts, where

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we talk astronomy and space science. Good to have your company.

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Coming up on this episode, we are, going to talk

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about the moon. It's got a near side, it's got a far side,

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but we're going to talk about the inside.

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it's, discovery of the Grail mission.

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which means what we're talking about is a flesh

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wound. another Hubble tension. Think about it.

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Another Hubble tension theory. And we're talking

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evolution this time. And a triple system in the

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Kuiper Belt. Belt. So buckle up for this

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episode of space nuts.

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Voice Over Guy: 15 seconds. Guidance is internal.

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10, 9. Ignition

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sequence start. Space nuts. 5, 4, 3,

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

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3, 2, 1. Space nuts. Astronauts

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report it feels good. And back with us

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again is Professor Fred Watson Watson, astronomer at

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large. Hello, Fred.

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Professor Fred Watson: Hello, Andrew. Hello. Took me in couple. Couple of

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seconds. But I did get the.

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Andrew Dunkley: To get the, flesh. The flesh wound. Flesh wound. The

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Grail mission.

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Professor Fred Watson: Only a flesh wound.

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Andrew Dunkley: It's only a flesh wound.

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Professor Fred Watson: That's right. no arms, no legs, but

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nothing.

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Andrew Dunkley: Flesh wound. so, yes, that I,

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I can't help dad jokes and, and, and

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I, I. When I do the presentations at golf on

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Fridays, which has become my job somehow.

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I always have to finish on a dad joke. It's just become a

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thing.

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Professor Fred Watson: Yes, yes, I'm sure it has.

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Andrew Dunkley: The reputation continues to spread. we'll be

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talking dad jokes in our next episode,

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our Q A episode as well.

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we should begin with this,

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Grail mission and the findings of the moon's

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unusual interior. This might

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come as a surprise to some people.

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Professor Fred Watson: Well, I think it does. Excuse me. I think it did come

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as a surprise when the discovery was made as well. These, are,

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scientists from NASA and other institutions, missions.

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yeah, let's do the dad joke first. The, It's not Monty

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Python and the Holy Grail.

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Grail stands for Gravity Recovery and

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Interior Laboratory. And it was a mission,

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which I guess it was more than. It's probably a

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decade ago. it's a very, very

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neat piece, of research. And

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NASA, you know, the clever stuff that they do is just

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unbelievable.

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so what do you do if you want to sense the

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gravity of, a planet that

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you're flying over? You want to map out the gravitational

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details. And by doing that, you can

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work out what's underneath the surface. because

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that's usually what affects the gravity above

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the surface of a planet. And I'm Talking

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now about really minor,

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disorder, differences and discrepancies

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in gravity, how the Grail mission

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worked. and I'm kind of casting my memory back now.

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two spacecraft, in orbit around the

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Moon, separate in the same. They're both in

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the same orbit. They were separated, I think,

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by about 200 kilometres, one in front of the

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other. But the

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distance between them could be detected

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by microwave transmission

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to well under a millimetre. I can't remember what

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it was. It was a few microns, I think. But

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this tiny, tiny difference between the

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position of the two spacecraft, you can measure it,

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by these microwave signals. And so as the two

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spacecraft go around the moon, their

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separation changes slightly as a result of the

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gravitational force, gravitational pull of the

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terrain beneath them. and it actually

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is a, really very sensitive

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way. I love the fact that they

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rediscovered, something that we talked about in

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the very earliest, history of moon exploration.

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Back in the, Gemini and Apollo era, back in the

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19, 60s, mass, cons,

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which were mass concentrations, concentrations

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of mass that were unexpected underneath the Moon's surface. They

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were actually measured just by spacecraft that were

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orbiting. Single spacecraft orbiting the

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Moon. but, GRAIL actually mapped them out in much

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more detail. We know a lot more about these mascons now than we did

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before. But what has happened,

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and by the way, I should just mention one, I should have

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put this in as a, As a quirky factoid, shouldn't I?

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Flippant factoid that the two,

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spacecraft, the two components of Grail. Do you remember what they were

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called?

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Andrew Dunkley: Oh, no.

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Professor Fred Watson: Ebb and flow. And it came.

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I think it was school kids who did that. If I remember rightly,

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NASA sent out a competition saying, we've got two spacecraft in

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orbit around the Moon. What do you want to call them? And they were called ebb and

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flow, which is very, very nice

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indeed. Anyway, ebb and flow, in

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combination, measured, virtually the

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gravitational map of the whole Moon. But

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what has come to light

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is something a little bit more subtle.

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these, researchers who've now used these

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NASA data to deduce that

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There's a, 2 to 3%

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difference in the

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ability of the lunar mantle. Now, that's

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the layer below the crust. That's the

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layer that surrounds the core of the Moon. The

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ability of the mantle to

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deform. So what you're

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saying is there's a difference in sort of

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flexibility from one side of the Moon to the other.

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And remember, as we know The Moon always faces the

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same side to Earth. and so that's, you know, there's

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a different gravitational pull on one side from what there is on the

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other. but what they've interpreted this difference

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as being, they say it's

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symptomatic. The fact that there's this difference in

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the Moon's mantles ability

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to deform, to change its shape.

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they say that is best explained

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by the temperature inside

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the mantle on the near side

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being as much as 170 degrees

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Celsius hotter than what it is on

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the other side. Wow, that's a side facing us. Yeah, it

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is. It's not a small amount, it's not a few degrees, it's a lot.

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and it's enough to change the viscosity of the mantle,

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how flexible it is. and so

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that's the new finding that's come from

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ebb and flow. And I think what they're saying is that

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the spacecraft was in orbit for long enough that it

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could detect differences in the

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gravitational pull as it flew over the same part of

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the Moon more than once. It could see a difference in the

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gravitational pull from one trip to another. So there's a

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time dependent thing on it, and that's how they know

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about the Moon's ability to deform. I'm

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actually, interpreting that in my own way.

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There's a nice paper in Nature

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magazine, perhaps one of the two leading

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journals for science in the world, which has the title of

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thermal asymmetry in the Moon's mantle

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inferred from monthly tidal response.

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Andrew Dunkley: Okay, so my question

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straight up is, could that explain,

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or does that explain why the near side

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and the far side of the Moon are so

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very different? when you're talking topography,

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yeah, I.

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Professor Fred Watson: Think it's the other way around. I suspect the difference in

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topography is, what

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causes the difference. Although they're probably all

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mishmashed up,

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into the same sort of thing.

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But the Moon's nearside,

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I think probably the way you've put it, actually Andrew,

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is probably more correct. The Moon's nearside,

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has had much more volcanic activity

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than the far side. This is between 3 and 4 billion

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years ago. It was highly volcanically active, which is why we've

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got all these lava flows on the near side, which we see as

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the maria, the grey patches on the Moon.

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but the details of what

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these researchers think, contributes

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to the difference, in temperature,

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they suggest I might actually, I think this is

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Nature's press release So I might just read

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straight from it.

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they hypothesise that this thermal

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difference could be sustained by radioactive

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decay of thorium and titanium within the moon's

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near side, which could be a remnant of

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the volcanic activity that formed the near side surface

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3 to 4 billion years ago.

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Andrew Dunkley: That is really interesting. Yeah,

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I'm fascinated

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by a couple of things, that we're using old data to make new

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discoveries. We've talked about that in other

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studies that have more papers that have been released in

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recent years. also the fact that there's

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effects on the moon that we see in

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other parts of the solar system, with, with

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variations in the way the moons

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interact with their host planet for example. I

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suppose.

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Professor Fred Watson: Yes.

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Andrew Dunkley: It's a similar situation is it not?

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Professor Fred Watson: Yes, that's right. So you've got and in fact most of these

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moons around, certainly the giant planets are ah,

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which is where most of the moons in the solar system are.

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there's only three in the inner solar system. Ours and

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Mars is two little satellites. But

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places like Enceladus, Ganymede, perhaps

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Callisto, Europa, around Jupiter, perhaps

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Titan as well, they,

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they could do use

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this technology to

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actually interpret what's going on

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inside these worlds without having to land

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a spacecraft on the surface. That's the,

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the great thing because putting something into orbit around

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Enceladus for example, would be much

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more straightforward, much less energy

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hungry than putting a spacecraft down onto

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the surface where you've got all the risks of

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collisions and tipping over like several

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of the lunar probes have done, they've fallen over.

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all of that is the hazard when you're

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landing something on the surface. So yeah, I think

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it's got a future. Now. you can,

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as I kind of mentioned earlier, you can do some of this

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kind of work with a single spacecraft, but if

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you can launch two with this microwave,

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microwave bridge between them, then you can do much, much

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more as the Grail spacecraft

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demonstrated.

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Andrew Dunkley: Okay, so yeah, the moon is not as

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it seems, at least not on the inside.

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Professor Fred Watson: Well no, that's right. Or maybe, maybe it is

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as it seems because the two sides are so different

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when you look at them. As you said, the topography

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is quite different from one side to the other.

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Andrew Dunkley: It's a great story. If you'd like to read up on that, you

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can find, you can go find the paper if you can remember the title of

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it because it's got more than three words in it. So I'm stuffed.

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But yeah, DailyGalaxy.com is

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the website. DailyGalaxy.com

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this is space Nuts with Andrew Dunkley and Professor

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Fred Watson Watson.

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Three, two, one.

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Professor Fred Watson: Space Nuts.

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Andrew Dunkley: Fred Watson, I neglected to mention my office

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background at the beginning. if I just put my thumb

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over the camera, people on YouTube will see

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a massive mountain there. That's the Fugo

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volcano in Guatemala. I took that photo on the

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7th of April. And Judy and I

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have a history of visiting volcanoes, getting home and then finding

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out they started erupting. And that's exactly what's happened with

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Fugo. So if you're on YouTube and you're watching us, when

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we're finished, go and have a look at some of the eruption

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footage from the Fugo volcano in Guatemala at

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the moment. It is spectacular. We had to drive

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between three volcanoes to get

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to the township of Antigua and

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you could see these things for miles. I mean

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they're strata volcanoes, they are absolutely

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enormous. They're around 12,

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13,000ft at the peak above sea level.

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and they are spectacular. And we

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literally had to drive between two of them to get to the

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town. That one was on our left and the

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agua volcano was on our right. and

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the town is in the foothills of the the two nearest

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volcanoes. And it's just an awe

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inspiring sight. But I just thought it was funny that

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well maybe not funny haha, but funny that we went to

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Hawaii, got home and Kilauea

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erupted. Happens a lot. I went to

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Vanuatu, Matt Yasser, got home, it

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erupted and stopped air traffic for a couple of weeks. And

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now this one's erupting a month after we were there.

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So we're not going to be invited back I don't think.

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But Fugo's got a history though it

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erupts quite often. But I just thought people would be interested

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to see a photo of it. as you know, I'm a

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volcano junkie.

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Professor Fred Watson: So when we were in Iceland earlier in the year, the

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Reykjanes peninsula had just

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erupted as well. Well here there was a

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lot of steam coming up from from the, you know, the fishes in the

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ground.

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Andrew Dunkley: Yeah. In the next few months we'll be visiting

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the Canary Islands.

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Professor Fred Watson: Sure.

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Andrew Dunkley: Yeah. So that one's got an active volcano

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and we're visiting Iceland as well.

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yeah. Could, could have some stories to tell.

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Professor Fred Watson: Yeah.

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Andrew Dunkley: Ah, good. Okay Fred Watson, let's move on

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to our next story.

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And this one is about yet again,

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the Hubble tension, the, the

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quirk of space that we

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can't quite get our heads around. We can't solve the

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differentials or the problems. Many are saying, look,

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it's natural. But Now

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another Hubble Tension theory, gee that's

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hard to say. is making its way

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into various papers. one in particular I

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suspect, because now they're talking about

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evolution in dark matter.

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This sounds like pie in the sky

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type stuff but we've got to, we've got to come up with

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answers. The only way it is to publish papers with

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theories and you know,

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toss it around.

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Professor Fred Watson: Indeed.

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Andrew Dunkley: That's like, like a salad. A space

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salad.

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Professor Fred Watson: yeah, I've just I'm m hesitating because I've just seen who one of the

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authors of this paper is.

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it's a scientist who's known for

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provocative papers. Avi

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Loeb, and he's at Harvard, Smithsonian,

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Centre for Astrophysics. So the

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paper that we're talking about is called Evolving Dark Energy

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or Evolving Dark Matter.

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and this is really esoteric

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stuff, Andrew. Always when we're talking about this

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stuff we're just glossing over

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a lot of really detailed

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science that goes into

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realms that even I struggle with. And I'm not

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actually a cosmologist, which is why. But

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I'm supposed to know my way around some of these topics

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better than perhaps the person in the street is.

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and this

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comes down to something called the equation of states which you and I

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haven't talked about. But the equation of state

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is a parameter in the universe.

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It's a parameter generally. It comes from thermodynamics,

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which essentially characterises,

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as the name almost implies, it

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characterises the overall behaviour of the

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universe. The equation of states, okay, Symbolised

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by the, the character W.

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so the, the work that's

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being reported here. and as I've said

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it's on a, on a, there's a, there's a.

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Basically a preprint as we used

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to call them. this is a paper that's not yet been

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refereed which is

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going to go into. I can't see

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what journal it's aiming for but it

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is called

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essentially the title of the paper Evolving Dark Energy

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or Evolving Dark Matter. I'm going to read you the

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abstract, okay? because that

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kind of tells the story even if you don't

351
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know what the details are. We

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show that the latest empirical

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constraints on cosmology, and by that they mean

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measured, from a Combination of desi, that's

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the Dark Energy Survey instrument cmb,

356
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that's the cosmic microwave background and supernova

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data, that's exploding stars. They've taken

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all this data together. The empirical

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constraints on cosmology from that combination can

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be accounted for. If a small

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component of dark matter

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has an evolving and oscillating

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equation of state within the range minus

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1 is greater than less than w, which is

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less than 1, that's the range minus 1 to 1 is

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somewhere where this equation of state parameter, W

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lies. From a fundamental physics perspective,

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this interpretation is more appealing

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than an evolving phantom dark energy with

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W less than minus 1, which

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violates the null energy condition.

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So in a sense this paper

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is kind of in response to

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what we're seeing from the latest data actually from

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desi, the Dark Energy Survey,

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which suggests that dark

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energy is getting less.

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Or at least what it suggests is the acceleration of

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the universe's expansion is getting less.

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In other words, the expansion which we know is accelerating

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because that's been well measured. But the suggestion

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is that that acceleration is slowing

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down, so as time goes on it will be

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accelerating at a lower rate. What

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they're saying is, when you look at the

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00:18:08.670 --> 00:18:11.630
sort of theory that doesn't make sense, but it makes

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more sense if something is going

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on with dark matter, that

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00:18:17.510 --> 00:18:20.460
dark matter, is itself

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00:18:20.460 --> 00:18:22.720
evolving. Now that

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00:18:23.280 --> 00:18:26.040
suggests, and they apparently explore this in the

392
00:18:26.040 --> 00:18:29.040
paper, I haven't read the paper, but they explore this,

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that suggests that dark matter is something

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different from what we think it is because we

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imagine dark matter as being some

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00:18:37.040 --> 00:18:39.890
subatomic particle, which is as yet

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unknown, which does not interact with normal matter at

398
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all, which is why we can't see it, and all

399
00:18:45.720 --> 00:18:48.120
it reveals itself by is its gravity.

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That's the parameters that we understand dark matter to

401
00:18:51.440 --> 00:18:54.250
be. But what they're suggesting

402
00:18:54.650 --> 00:18:57.530
is that this is something even more

403
00:18:57.530 --> 00:19:00.170
exotic than we have been imagining,

404
00:19:00.830 --> 00:19:03.590
because its parameters

405
00:19:03.590 --> 00:19:06.520
change, its phenomena change and

406
00:19:06.470 --> 00:19:09.230
that leads to a changed equation of state,

407
00:19:09.950 --> 00:19:11.230
the W parameter.

408
00:19:14.190 --> 00:19:16.780
And they actually suggest,

409
00:19:17.720 --> 00:19:20.680
that actually there's some sort of oscillation going

410
00:19:20.680 --> 00:19:22.920
on in it as well. Not just dark matter.

411
00:19:23.480 --> 00:19:25.720
There's a very nice article on physics

412
00:19:25.800 --> 00:19:28.750
phys.org by Brian

413
00:19:28.750 --> 00:19:31.640
Koberlein. I'm going to read a paragraph

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00:19:31.720 --> 00:19:32.280
for it.

415
00:19:34.710 --> 00:19:36.550
in fact I'm going to read a couple,

416
00:19:37.580 --> 00:19:40.520
let me just read from this because I think that's going to explain

417
00:19:40.520 --> 00:19:42.440
it better than me waffling on.

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In work published on the Arxivist print server, the

419
00:19:46.140 --> 00:19:49.060
Authors look at both evolving dark energy and evolving

420
00:19:49.060 --> 00:19:52.060
dark matter and argue that the latter is a

421
00:19:52.060 --> 00:19:55.020
much better fit to the observational data. The first thing they know

422
00:19:55.020 --> 00:19:57.500
is that the two models are somewhat related. Since the

423
00:19:57.500 --> 00:20:00.420
evolution of the cosmos depends in part on

424
00:20:00.420 --> 00:20:02.940
the ratio of dark energy to matter density,

425
00:20:03.500 --> 00:20:06.500
a model with constant dark matter, which is what we have at

426
00:20:06.500 --> 00:20:08.780
the moment, and evolving dark energy,

427
00:20:09.290 --> 00:20:12.090
will always appear similar to a model with

428
00:20:12.090 --> 00:20:14.810
evolving dark matter and a constant dark energy.

429
00:20:15.130 --> 00:20:18.130
That's a good point. They then go on to explore the idea of

430
00:20:18.130 --> 00:20:21.130
some kind of exotic dark matter, one that has a changeable

431
00:20:21.130 --> 00:20:23.930
equation of state to match observation. The dark

432
00:20:23.930 --> 00:20:26.730
matter equation of state must oscillate

433
00:20:26.730 --> 00:20:29.730
in time. This isn't an outlandish

434
00:20:29.730 --> 00:20:32.650
notion. I think they're trying to convince

435
00:20:32.650 --> 00:20:34.650
us here in space.org

436
00:20:35.130 --> 00:20:37.770
neutrinos have mass and don't interact

437
00:20:37.770 --> 00:20:40.730
strongly with light. While they can't account for all the dark matter

438
00:20:40.730 --> 00:20:43.530
in the universe, they are a form of hot dark matter.

439
00:20:43.950 --> 00:20:46.640
And neutrinos undergo, mass oscillation.

440
00:20:47.280 --> 00:20:49.810
Perhaps cold and dark matter particles undergo,

441
00:20:50.290 --> 00:20:53.290
Sorry. Perhaps cold dark matter particles undergo

442
00:20:53.290 --> 00:20:55.770
a similar oscillatory, effect.

443
00:20:56.490 --> 00:20:59.090
The authors find that the best fit to

444
00:20:59.090 --> 00:21:01.530
observational data is a universe where about

445
00:21:01.530 --> 00:21:03.780
15% of the cold dark matter is oscillatory,

446
00:21:04.930 --> 00:21:07.570
and the remaining 85% is

447
00:21:07.570 --> 00:21:10.390
standard dark matter. This would allow for

448
00:21:10.390 --> 00:21:13.230
the Hubble tension to be covered while

449
00:21:13.230 --> 00:21:16.070
still matching the dark matter observations we

450
00:21:16.070 --> 00:21:18.430
have. And I love the last paragraph.

451
00:21:18.590 --> 00:21:20.510
Andrew Dunkley: Yeah, I do too. I was just reading it.

452
00:21:20.750 --> 00:21:23.750
Professor Fred Watson: It should be stressed that this work presents

453
00:21:23.750 --> 00:21:26.750
a toy model. As the authors themselves note, the

454
00:21:26.750 --> 00:21:29.270
work is a broad concept that does not pin down specific

455
00:21:29.270 --> 00:21:32.230
constraints for dark matter particles. But the work does open the door to

456
00:21:32.230 --> 00:21:35.230
a broader range of dark matter models. At this point,

457
00:21:35.310 --> 00:21:38.270
evolving dark matter is worth considering. Well, I agree with that.

458
00:21:38.340 --> 00:21:40.020
I think everything's worth calling.

459
00:21:40.020 --> 00:21:42.940
Andrew Dunkley: I was going to ask you where you stand on this and if

460
00:21:42.940 --> 00:21:45.700
it's worth considering, then obviously it is. But

461
00:21:46.980 --> 00:21:49.220
it just adds another potential

462
00:21:50.260 --> 00:21:53.140
explanation of something we know very little

463
00:21:53.140 --> 00:21:54.340
about and.

464
00:21:54.660 --> 00:21:57.460
Professor Fred Watson: Yep. And we worry about a lot, especially

465
00:21:57.540 --> 00:21:58.820
on space. Nuts.

466
00:21:58.820 --> 00:22:01.700
Andrew Dunkley: Yes, yes. And we get a lot of questions about it. And

467
00:22:01.780 --> 00:22:04.500
so a lot of people thinking about this stuff,

468
00:22:05.170 --> 00:22:06.850
if it's, if it's in fact stuff.

469
00:22:07.010 --> 00:22:09.890
Professor Fred Watson: Yes, well, yes, that's right. It could be something other than

470
00:22:09.890 --> 00:22:10.290
stuff.

471
00:22:10.290 --> 00:22:13.110
Andrew Dunkley: Yes, yes. So, yeah, it's a

472
00:22:13.190 --> 00:22:16.190
really interesting idea and, well, I

473
00:22:16.190 --> 00:22:19.040
suppose, it'll get tossed around and people will come up with other

474
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explanations. But the thing is, a paper

475
00:22:21.850 --> 00:22:24.170
like this, even if it's wrong may

476
00:22:24.250 --> 00:22:27.170
spawn a level of thinking that might send us down

477
00:22:27.170 --> 00:22:30.010
a path where we might eventually figure it out. I mean that's another

478
00:22:30.440 --> 00:22:30.840
possibility.

479
00:22:31.640 --> 00:22:33.590
Professor Fred Watson: that's, that's true. That's correct.

480
00:22:34.580 --> 00:22:37.380
and that's the way science works as well. Exactly as you've

481
00:22:37.380 --> 00:22:37.620
said.

482
00:22:37.620 --> 00:22:38.500
Yes, indeed.

483
00:22:38.500 --> 00:22:41.460
Andrew Dunkley: All right. as Fred Watson said, you can read

484
00:22:41.460 --> 00:22:44.420
all about it@the phys.org website. That's

485
00:22:44.420 --> 00:22:47.220
P-Y-S.org or you can

486
00:22:47.220 --> 00:22:50.180
read the published paper on the archive reprint

487
00:22:50.180 --> 00:22:52.860
server if you like. This is Space Nuts. Andrew

488
00:22:52.860 --> 00:22:54.580
Dunkley here, Fred Watson Watson there.

489
00:22:57.190 --> 00:22:58.950
Okay, we checked all four systems.

490
00:23:01.350 --> 00:23:03.910
Our final topic today, Fred Watson,

491
00:23:04.020 --> 00:23:06.720
is a really interesting one and it

492
00:23:06.720 --> 00:23:09.440
is going to take us to the Kuiper

493
00:23:09.440 --> 00:23:09.920
Belt.

494
00:23:09.920 --> 00:23:12.920
So tighten up your buckle and get ready for

495
00:23:12.920 --> 00:23:15.920
this one because we think there has

496
00:23:15.920 --> 00:23:18.840
been discovered a triple system in the Kuiper

497
00:23:18.840 --> 00:23:21.760
Belt. Now when we talk about the Kuiper

498
00:23:21.760 --> 00:23:24.690
Belt we don't really, we've only been there a

499
00:23:24.690 --> 00:23:27.600
couple of times. fairly recent missions in the last

500
00:23:27.600 --> 00:23:30.520
decade or so. But we've only had close

501
00:23:30.800 --> 00:23:33.760
up observations of two objects in the

502
00:23:33.760 --> 00:23:35.640
Kuiper Belt. So

503
00:23:36.520 --> 00:23:39.160
this discovery was actually made not by

504
00:23:39.160 --> 00:23:42.000
either of those probes but, or the

505
00:23:42.000 --> 00:23:44.670
probe in question. it was made from

506
00:23:44.670 --> 00:23:46.350
Earth, am I correct?

507
00:23:46.510 --> 00:23:49.460
Professor Fred Watson: Yes, that's right. using the Hubble

508
00:23:49.460 --> 00:23:50.450
Space Telescope.

509
00:23:50.840 --> 00:23:51.240
Andrew Dunkley: Yeah.

510
00:23:52.040 --> 00:23:54.910
Professor Fred Watson: Which is you know, still going strong

511
00:23:54.990 --> 00:23:57.600
and still a

512
00:23:57.600 --> 00:23:58.920
fantastic resource

513
00:24:00.270 --> 00:24:02.670
given that it's now 35 years

514
00:24:03.230 --> 00:24:05.990
in space. Yes, it is amazing. That's

515
00:24:05.990 --> 00:24:08.910
right. so, and again this is a team

516
00:24:08.910 --> 00:24:11.670
of researchers from NASA. what they've been doing is

517
00:24:11.670 --> 00:24:14.630
looking through ah, Hubble telescope data

518
00:24:14.790 --> 00:24:17.500
at this very distant object

519
00:24:18.780 --> 00:24:21.510
which is it's a, an asteroid. So it's got a number

520
00:24:21.510 --> 00:24:24.310
148780 and

521
00:24:24.310 --> 00:24:27.150
it's known as Algeria. that's its name.

522
00:24:27.950 --> 00:24:30.510
and they, they,

523
00:24:31.070 --> 00:24:33.870
they haven't seen the three

524
00:24:33.870 --> 00:24:36.830
bodies that they now think make it up, but they've seen

525
00:24:36.830 --> 00:24:37.150
two.

526
00:24:37.230 --> 00:24:38.990
Andrew Dunkley: Wait, dad, joke coming.

527
00:24:39.070 --> 00:24:40.830
Professor Fred Watson: Oh good. Okay. They're seeing two of them.

528
00:24:42.010 --> 00:24:44.650
Andrew Dunkley: I was going so they haven't seen the three bodies. That's a problem.

529
00:24:45.370 --> 00:24:48.140
Professor Fred Watson: Oh, there we go. Love it. Love

530
00:24:48.140 --> 00:24:51.020
it. I

531
00:24:51.020 --> 00:24:53.980
don't understand. You must rehearse our conversations weeks in

532
00:24:53.980 --> 00:24:55.220
advance, Andrew, to get.

533
00:24:55.220 --> 00:24:57.900
Andrew Dunkley: No, the scary part is this

534
00:24:57.900 --> 00:24:59.620
garbage just pops in there

535
00:25:00.980 --> 00:25:03.820
at random moments. It used to happen

536
00:25:03.820 --> 00:25:06.500
when I was on the radio. I'd just be talking about something

537
00:25:07.460 --> 00:25:09.780
and a little voice ago, hey, tell this joke.

538
00:25:10.020 --> 00:25:12.940
Professor Fred Watson: Yeah. And then at the end of it you think I got a Wish

539
00:25:12.940 --> 00:25:15.580
I hadn't said that. Yes, yeah.

540
00:25:15.580 --> 00:25:17.340
Andrew Dunkley: Ah, yeah, yeah.

541
00:25:17.340 --> 00:25:20.250
Professor Fred Watson: Anyway, so it's, it,

542
00:25:20.250 --> 00:25:23.090
it basically is new, ah, research.

543
00:25:23.170 --> 00:25:25.850
And so, so they can see two. They can

544
00:25:25.850 --> 00:25:27.970
detect that there are two objects

545
00:25:28.770 --> 00:25:29.890
orbiting one another.

546
00:25:30.130 --> 00:25:31.170
Andrew Dunkley: I sent the but.

547
00:25:32.370 --> 00:25:35.200
Professor Fred Watson: The butt is. Yes, yes. the

548
00:25:35.200 --> 00:25:38.000
but is that it looks as though one of them is actually

549
00:25:38.000 --> 00:25:40.280
a pair of objects. That's the trick.

550
00:25:41.160 --> 00:25:44.040
So we've got two things that have been

551
00:25:44.040 --> 00:25:46.560
seen, but one of them is

552
00:25:46.560 --> 00:25:49.400
probably a double. And they've had to

553
00:25:49.400 --> 00:25:52.360
use the very detailed,

554
00:25:52.670 --> 00:25:54.830
measurements of the way

555
00:25:55.390 --> 00:25:58.230
the object that they can see orbits the other

556
00:25:58.230 --> 00:26:00.990
one, the way that orbit changes.

557
00:26:01.280 --> 00:26:03.360
that is what tells you that the

558
00:26:04.160 --> 00:26:06.920
central object, if I can put it that way, might actually

559
00:26:06.920 --> 00:26:09.350
be two. and so it's the

560
00:26:09.430 --> 00:26:12.300
outer object, its orbit changes

561
00:26:12.300 --> 00:26:14.820
over time. And it's that change,

562
00:26:15.360 --> 00:26:18.350
that allows the deduction that the central

563
00:26:18.670 --> 00:26:21.390
object, if I put it that way, is.

564
00:26:23.230 --> 00:26:25.790
Well, they say it's either extremely

565
00:26:25.790 --> 00:26:28.590
elongated or it's two separate objects.

566
00:26:29.290 --> 00:26:31.760
And that, you know, the odds are that it is actually

567
00:26:31.840 --> 00:26:34.750
probably two. often though, we've

568
00:26:34.750 --> 00:26:37.190
got this situation, especially with these

569
00:26:38.390 --> 00:26:41.110
distant, asteroids, where you

570
00:26:41.110 --> 00:26:44.029
have clearly something that has been

571
00:26:44.029 --> 00:26:46.830
a binary, two objects in orbit around one another,

572
00:26:46.830 --> 00:26:49.700
but they've gradually, collapsed together,

573
00:26:49.860 --> 00:26:52.660
not in a violent way, and wound up in

574
00:26:52.660 --> 00:26:55.490
contact, which is something we call, believe it or not, a

575
00:26:55.490 --> 00:26:58.460
contact binary. And Arrokoth, it's one

576
00:26:58.460 --> 00:27:01.260
of the Kuiper Belt objects that you actually

577
00:27:01.500 --> 00:27:04.260
just referred to. It's beyond the orbit of Pluto. It was

578
00:27:04.260 --> 00:27:07.250
visited by New Horizons. when we saw it, it looked like

579
00:27:07.250 --> 00:27:10.210
a snowman. And that was very seasonal because I think it was

580
00:27:10.210 --> 00:27:13.200
Christmas time, when it was discovered. But

581
00:27:13.200 --> 00:27:16.100
the analysis of, New Horizons data as it

582
00:27:16.100 --> 00:27:18.940
flew past Arrokoth showed that it wasn't actually

583
00:27:18.940 --> 00:27:21.620
two balls joined together. It was two pancakes joined together,

584
00:27:22.240 --> 00:27:25.100
rim to rim, so that it actually looked like a snowman,

585
00:27:25.100 --> 00:27:28.020
but from the edge on, it looked a lot more like two pancakes

586
00:27:28.020 --> 00:27:30.500
stuck together. But that's a common

587
00:27:30.500 --> 00:27:33.460
phenomenon. Two objects, whatever their shape, is coming

588
00:27:33.460 --> 00:27:35.100
together gently and actually,

589
00:27:36.440 --> 00:27:39.280
basically cementing themselves together just by gravity. But

590
00:27:39.280 --> 00:27:42.200
then the sort of gap between them fills in and you end

591
00:27:42.200 --> 00:27:45.080
up with something that looks like a peanut. So

592
00:27:45.080 --> 00:27:47.760
I think it's still possible that

593
00:27:47.840 --> 00:27:50.680
Algeria could have that sort of

594
00:27:50.680 --> 00:27:53.440
shape. But they actually say,

595
00:27:53.600 --> 00:27:56.600
the research team who's done this, they say that

596
00:27:56.600 --> 00:27:59.200
the triple system actually fits the data

597
00:27:59.280 --> 00:28:01.980
best. it fits it better

598
00:28:02.539 --> 00:28:05.500
than a contact binary or a really elongated

599
00:28:05.580 --> 00:28:08.500
central object. So a triple system is what we

600
00:28:08.500 --> 00:28:11.490
Believe it is, it's a very nice target for

601
00:28:11.490 --> 00:28:14.250
a future mission to the outer solar system, but

602
00:28:14.250 --> 00:28:16.980
that's not going to happen anytime soon. but, yeah,

603
00:28:16.980 --> 00:28:19.810
so, very nice discovery. Triple systems are rare.

604
00:28:19.810 --> 00:28:22.780
That's why, that's why it, you know, it's making the

605
00:28:22.780 --> 00:28:25.540
headlines. These are rare phenomena.

606
00:28:25.540 --> 00:28:28.380
Binaries are very common. In fact, probably most

607
00:28:28.380 --> 00:28:31.020
objects out there in this outer solar system might be

608
00:28:31.020 --> 00:28:32.670
binaries, but triple systems are rare.

609
00:28:33.910 --> 00:28:36.640
Andrew Dunkley: interestingly, this, rock, if you want to call it that,

610
00:28:36.640 --> 00:28:39.480
or system Algeria, is

611
00:28:39.480 --> 00:28:42.280
much, much bigger than Arrokoth. it's, about

612
00:28:42.280 --> 00:28:44.840
124 miles wide, or 200

613
00:28:44.840 --> 00:28:46.680
kilometres. That's a big chunk.

614
00:28:47.190 --> 00:28:49.740
Professor Fred Watson: Yes, it is, yes. A lot, more substantial than

615
00:28:49.740 --> 00:28:52.740
Arrokoth, which was only, if I remember right, it was less than a kilometre, I

616
00:28:52.740 --> 00:28:55.690
think. it's amazing that they found it at all. To

617
00:28:56.330 --> 00:28:59.070
give New Horizons a target beyond, Pluto.

618
00:29:00.030 --> 00:29:02.920
Andrew Dunkley: Yeah, yeah, as you say, we're probably not going to go

619
00:29:02.920 --> 00:29:05.440
back out there in a hurry. These missions are very

620
00:29:06.160 --> 00:29:08.720
long winded because of the distances

621
00:29:08.720 --> 00:29:10.480
involved. We're talking what,

622
00:29:11.900 --> 00:29:14.060
30 or 30 AU or something?

623
00:29:14.540 --> 00:29:17.500
Professor Fred Watson: Yeah, I think this is more, I think it's more like 45 AU or

624
00:29:17.500 --> 00:29:20.180
something like that. So it's. Yeah, AU is an

625
00:29:20.180 --> 00:29:22.460
astronomical unit, 150 million

626
00:29:22.460 --> 00:29:23.260
kilometres.

627
00:29:23.260 --> 00:29:25.850
Andrew Dunkley: Yeah, that's a long way away. but

628
00:29:26.890 --> 00:29:29.570
yeah, it's probably an area of our

629
00:29:29.570 --> 00:29:32.570
solar system, even though it's so remote, that we need to learn more

630
00:29:32.570 --> 00:29:34.250
about because, you know,

631
00:29:35.940 --> 00:29:38.580
some of these rocks get bumped and end up heading our way.

632
00:29:39.570 --> 00:29:42.270
Professor Fred Watson: yes, that's right, they do, or, you know,

633
00:29:42.270 --> 00:29:45.140
gravitationally interact with other objects. but you're right,

634
00:29:46.650 --> 00:29:49.130
in some ways it's the last frontier. It's completing

635
00:29:49.850 --> 00:29:52.610
the evidence for the way we think. Our

636
00:29:52.610 --> 00:29:55.050
solar system formed by this icy,

637
00:29:55.660 --> 00:29:58.560
dust and gas cloud that collapsed. And a

638
00:29:58.560 --> 00:30:01.170
lot of this stuff is the last vestiges, the

639
00:30:01.170 --> 00:30:03.290
outer, the outer vestiges of those,

640
00:30:04.010 --> 00:30:06.840
you know, those, objects that eventually went up to

641
00:30:06.840 --> 00:30:09.680
make the inner planets. These are, these are worlds that have never been

642
00:30:09.680 --> 00:30:12.680
heated. And that's the, you know, the planets have

643
00:30:12.680 --> 00:30:15.200
been, they've been bombarded by gravitational

644
00:30:16.000 --> 00:30:19.000
interactions by collisions and, impacts

645
00:30:19.000 --> 00:30:21.870
and things of that sort, so that they're hot. these worlds

646
00:30:21.870 --> 00:30:24.550
have always been cold and that's why they're so

647
00:30:24.550 --> 00:30:27.310
interesting, because they're sort of the fossil of the solar

648
00:30:27.310 --> 00:30:28.350
system's earliest history.

649
00:30:28.900 --> 00:30:29.700
Andrew Dunkley: Yeah. Yeah.

650
00:30:29.700 --> 00:30:32.660
Well, I guess the time will come where we do extensive studies, but,

651
00:30:32.610 --> 00:30:34.930
I think we'll have to get better spacecraft and

652
00:30:35.490 --> 00:30:38.490
maybe use those, superhighways you were talking

653
00:30:38.490 --> 00:30:38.730
about.

654
00:30:38.730 --> 00:30:39.890
Professor Fred Watson: Yeah, yeah, that's right.

655
00:30:39.890 --> 00:30:41.090
Andrew Dunkley: Get out there and have a look.

656
00:30:41.570 --> 00:30:41.960
Professor Fred Watson: Yes.

657
00:30:41.960 --> 00:30:44.600
Andrew Dunkley: if you'd like to read up on that, you can do that at the

658
00:30:44.600 --> 00:30:47.430
NASA science website or you can go, to the

659
00:30:47.430 --> 00:30:49.990
study itself, which was published in the Planetary

660
00:30:49.990 --> 00:30:52.780
Science Journal. that brings us

661
00:30:52.780 --> 00:30:54.940
to the end. Fred, thank you so much.

662
00:30:55.690 --> 00:30:58.650
Professor Fred Watson: it's a pleasure, Andrew. a nice surprise to see you and, always

663
00:30:58.650 --> 00:30:59.610
a pleasure to talk.

664
00:31:00.410 --> 00:31:03.330
Andrew Dunkley: Good to see you too. And we'll catch you on the very

665
00:31:03.330 --> 00:31:06.090
next episode. Don't forget to visit us online. In the meantime,

666
00:31:06.090 --> 00:31:08.940
we've got, plenty of platforms. We're on Instagram, we're

667
00:31:08.940 --> 00:31:11.740
on YouTube, we're on Facebook, we're on

668
00:31:11.740 --> 00:31:13.800
our own website, spacenutspodcast.com

669
00:31:14.080 --> 00:31:16.940
SpaceNuts IO Either URL will

670
00:31:16.940 --> 00:31:19.890
take you to the same place and have a look around while

671
00:31:19.890 --> 00:31:22.780
you're there. And, Huw in the studio, he

672
00:31:22.780 --> 00:31:25.500
did actually turn up briefly today, but he

673
00:31:25.500 --> 00:31:28.420
forgot to put on his kuiper belt and his pants fell down,

674
00:31:28.420 --> 00:31:31.300
so he had to make a run for it from

675
00:31:31.300 --> 00:31:34.220
me, Andrew Dunkley. Oh, it's terrible. Thanks, for your

676
00:31:34.220 --> 00:31:36.820
company. We'll see you on the next episode of Space Nuts.

677
00:31:36.820 --> 00:31:37.380
Professor Fred Watson: Bye. Bye.

678
00:31:38.460 --> 00:31:41.260
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679
00:31:42.780 --> 00:31:45.590
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680
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681
00:31:48.590 --> 00:31:50.310
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684
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