The Youngest Planet Ever Found

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Anna: Every planet you have ever heard of was

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already finished when we found it. Grown up,

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settled into its orbit. The

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disc of gas and dust it was built from

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long gone.

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Avery: Not this one. Astronomers have found a

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planet that is still being built, less than

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a million years old, sitting in the gap it is

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carving through its own birth cloud.

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Anna: Also today, a brand new crater on the

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Moon, a Victorian train delay that turns

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out to be a solar storm, and a dead star

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that has got six times hotter in 30 years.

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Avery: I'm Avery.

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Anna: And I'm Anna. This is Astronomy

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AstroDailyPod. Here is a number that should

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stop you.

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Every previously confirmed young planet,

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every single one held up as an example of a

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world caught in the act of forming, was at

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least 5 million years old. 5 million years

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sounds young. It is young. Our own

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solar system is about four and a half

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billion. But five million years is also long

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enough that the most interesting part is

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already over. The gas is mostly gone.

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The building is done. You are looking at the

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result, not the process. Yesterday in

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the Astrophysical Journal Letters, a team led

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from Chile published the confirmation of a

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planet that is less than 1 million years old,

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not 5, less than 1. It is

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called Elias 224B. And the most

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remarkable thing about it is that we are

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watching it being made.

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Avery: And this is one of those results where the

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storey of how we got there is as good as the

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result itself. Because the first hint of

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this planet is 9 years old, it

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is.

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Anna: Let me take you back to 2017. A team

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including Lucas Sieza, who is an author on

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today's paper as well, pointed Alma,

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the Big Millimetre array up on the Chagnantor

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Plateau in northern Chile at a young star in

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the Ophiuchus molecular cloud.

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Ophiuchus is one of the closest active star

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forming regions to us, about 450

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light years away. And from here in the

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southern hemisphere, it rides high across the

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winter sky. The star is catalogued as

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Elias224. It is a K

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type star, roughly the mass of the sun, but

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much cooler and much puffier because it has

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not finished contracting yet. What Alma saw

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was a disc of dust around that star with gaps

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in it. Dark rings, clean

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circular lanes swept through the dust. And

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the standard interpretation of a gap like

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that is simple and beautiful. Something

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massive is orbiting in there and its gravity

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is hurting the dust out of its path. The gap

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is the wake, a footprint

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Avery: rather than a foot.

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Anna: Exactly that. And footprints are frustrating

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because a gap can be made by other things.

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Ice lines, where a particular molecule

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freezes out and changes how the dust sticks

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together. Magnetic effects in the disc

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turbulence. For nine years,

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Elias224 has been a beautiful set of

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rings and an unproven assumption. What

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Andrea Bernardi at Universidad Diego Portales

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in Santiago did was go looking for the foot

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and the data had been sitting in an archive

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the whole time.

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Avery: This is the part I love.

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Anna: The W.M. keck Observatory on Mauna

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Kea observed this system in 2018

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and again in 2020 using a

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coronagraph on the NIRC 2

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infrared camera. A, uh, coronagraph is a

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mask that blocks the light of the star itself

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so you can see the much fainter things next

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to it. The same basic trick the Roman Space

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Telescope's coronagraph is being commissioned

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to do right now, which we talked about on

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Wednesday. Those Keck observations were

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taken, archived and not fully

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mined. Bernardi's team went back into them,

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reprocessed them and found a point of

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infrared light sitting inside one of the

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gaps. And here is Bernardi's line, which

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is the whole paper in one. The

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planets should be found within the gaps since

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they are carving them.

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And that's exactly where we found

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Elias224B, end quote.

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Avery: So the prediction and the detection line up.

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Anna: They line up and then the confirmation

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needed a third instrument. ESO's Very

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Large Telescope at Paranal in the Atacama

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had also caught a faint point of light in

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that gap. Put the three together.

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ALMA showing you the gap in millimetre dust.

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The the VLT and KECK both showing you an

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infrared source sitting in it at two separate

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epochs, two years apart. So you can cheque it

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is moving with the star rather than being a

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background object and you have a planet.

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Avery: Bernardi made a point of that in the release.

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Something like we usually hear about

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telescopes working separately. But this

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confirmation was only possible by using

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multiple telescopes together, which is worth

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sitting with for a second because it is also

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a storey about hemispheres. ALMA and

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the VLT are both in Chile. Keck is

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in Hawaii. Ophiuchus sits at about

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24 degrees south, so it is a target

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both hemispheres can reach. And it took all

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three facilities on both sides of the equator

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to nail this down. The southern telescopes

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found the gap and the northern telescope had

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the planet sitting in its archive. Now

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the physics and this is where it gets

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genuinely awkward for the textbooks.

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Elias224B is roughly the

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mass of Jupiter and it is orbiting about

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55 times further from its star than Earth

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is from the Sun. 55

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astronomical units for scale.

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Neptune is at 30, Pluto averages

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about 39. So this is a Jupiter

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mass planet out past where our own Kuiper

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Belt starts. And it got there in under a

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million years. And the standard way we build

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giant planets does not go that fast, that

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far out.

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Anna: It does not core accretion.

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The mainstream model says you assemble

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a solid core first by sticking pebbles

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together. And once that core is heavy enough,

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it starts pulling gas down onto itself and

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runs away into a gas giant. The trouble is

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that the further out you go, the thinner the

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disc is and the slower everything orbits.

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So there is less material and fewer

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collisions per orbit. Building a Jupiter at

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55 au by core accretion is slow.

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Estimates run to many millions of years.

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This planet did not have many millions of

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years. It had at the outside one.

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Lucas Sieza put it plainly,

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our planet formation models already struggled

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to explain the previous record holders.

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Elias224B shows us that even our best

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models are still missing some important

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processes. End quote.

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Avery: There is an alternative, isn't there? The

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disc fragmenting directly.

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Anna: There is gravitational instability.

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Instead of building a planet from the bottom

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up, you let a patch of the disc become dense

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enough that it collapses under its own

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gravity all at once and makes a giant

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planet more or less the way a star forms.

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That is fast, and it works better at large

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distances where discs are cooler and more

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prone to collapse. A planet like this one,

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this young, this far out, is exactly

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the sort of object people point to when they

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argue that gravitational instability has to

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be part of the picture rather than a, uh,

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curiosity. But I want to be careful here.

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And this is the caveat that does not come out

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of the script. Go on directly

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Imaged protoplanets have a history.

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Candidates around the stars Lkca 15

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and AB Orige were both announced as

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planets in the making, and both ended up

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disputed. In some cases, what looked like a

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planet turned out to be a bright knot of disc

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material or an artefact of how the starlight

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was subtracted. The system PDS 70

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is the one everybody agrees on, and that took

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years of independent confirmation. So

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Elias 224B is a strong detection

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with three telescopes behind it. And it is

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also a detection that will get tested hard

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over the next few years, as it should be.

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And the mass number deserves the same care.

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At an age under a million years, you cannot

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weigh a planet directly. You measure how

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bright it is in the infrared, and you convert

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that to, uh, a mass using models of how a

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young giant planet cools. Those models

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disagree with each other most severely at

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exactly this age, because they depend on how

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much heat the planet held onto from its

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formation. And some of the light you are

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seeing may not be the planet's surface at

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all, but gas falling onto it and glowing as

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it lands. So when we say Jupiter mass,

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read that as Jupiter ish, with real room on

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either side. An earlier kinematic estimate

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for whatever is carving that gap put it as

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high as five Jupiter masses.

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Avery: None of which changes the headline.

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Anna: None of which changes the headline. Something

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with the mass of a giant planet is

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sitting in that gap and the star it

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orbits is younger than our species.

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We have around 6,000 confirmed

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exoplanets now and almost every one of them

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is a finished product.

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This is a building site with the scaffolding

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still up and it is going to be observed

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to death, which is the correct fate for a

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result like this one.

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Avery: Moving on to storey two, sometime between

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11 April and 22 May

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2024, something the size of a three

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to six storey building hit the moon.

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Nobody saw it happen. We found the hole

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18 months later and the papers describing it

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were published yesterday in Science Advances.

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Anna: How big a hole?

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Avery: 222 metres across and

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about 43 metres deep. That is roughly

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two football pitches wide and a 14

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storey building deep. And here is the part

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that makes it news rather than trivia. It

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is about three times wider than the largest

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new crater found in the entire 17 years the

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lunar Reconnaissance Orbiter has been

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watching. The team put an impact this size

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at something like one in a hundred and thirty

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years. It is on the near side at about

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1.4 degrees north, 67

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degrees east, out on the outer ring of the

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crisium basin, roughly 20 kilometres

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east of Mare Speumens, right on the boundary

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where the bright highlands meet the dark Mare

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plains. It is being referred to informally

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by the name of its neighbourhood, Magecheon,

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after Thomas Magn, who once directed the

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Lunar and Planetary Institute.

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Formal naming is the IAU's business

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and that is a separate process.

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Anna: And nobody was looking at that patch of the

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moon at the time.

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Avery: Nobody was.

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It was found by Robert Wagner, an image

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processing specialist at Intuitive Machines,

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working with the orbiter's camera team. In

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October last year, doing routine data

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quality cheques, he was running software that

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compares before and after maps of the whole

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moon and flags. What has changed?

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His description of the moment is my favourite

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thing. In the release I just

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stopped, dropped everything and started

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looking into what that spot was.

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00:11:12.170 --> 00:11:14.690
What stood out was a bright splash of fresh

265
00:11:14.690 --> 00:11:17.530
ejecta. And the ejecta is the science.

266
00:11:17.930 --> 00:11:20.410
The continuous blanket of thrown out rock

267
00:11:20.569 --> 00:11:23.490
reaches a median of about 258

268
00:11:23.490 --> 00:11:26.250
metres from the centre. Bright disturbance

269
00:11:26.250 --> 00:11:28.250
shows up 15 kilometres out.

270
00:11:28.730 --> 00:11:31.570
Fainter, darker disturbance runs beyond a

271
00:11:31.570 --> 00:11:34.080
hundred kilometres. The biggest boulder they

272
00:11:34.080 --> 00:11:36.920
measured is 13 metres by 9 by 3

273
00:11:37.400 --> 00:11:40.040
from a hole 200 metres wide. The

274
00:11:40.040 --> 00:11:42.840
surface is measurably rearranged over an area

275
00:11:42.840 --> 00:11:44.360
the size of a small country,

276
00:11:44.920 --> 00:11:46.840
Anna: which is a lot of energy, about

277
00:11:46.840 --> 00:11:49.760
Avery: 65 trillion joules on assumptions of a

278
00:11:49.760 --> 00:11:52.760
rocky impactor at 15 kilometres a second.

279
00:11:53.160 --> 00:11:55.560
And the second paper is the one I would not

280
00:11:55.560 --> 00:11:56.520
have predicted.

281
00:11:56.840 --> 00:11:59.480
A team led by Powell went to Diviner,

282
00:11:59.750 --> 00:12:02.190
the orbiter's thermal instrument and found a

283
00:12:02.190 --> 00:12:04.630
cold spot about seven kilometres across,

284
00:12:04.630 --> 00:12:07.510
centred on the crater eight or nine Kelvin,

285
00:12:07.510 --> 00:12:10.030
cooler than its surroundings. That is the

286
00:12:10.030 --> 00:12:12.790
signature of fluffed up soil. The impact

287
00:12:12.950 --> 00:12:15.749
did not just dig a hole, it loosened the top

288
00:12:15.749 --> 00:12:18.390
layer of regolith across seven kilometres.

289
00:12:18.470 --> 00:12:21.030
And loose soil holds heat differently from

290
00:12:21.030 --> 00:12:23.510
packed soil. Mark Robinson, the

291
00:12:23.510 --> 00:12:26.030
camera's chief scientist, framed it as

292
00:12:26.030 --> 00:12:28.750
gardening impacts, as the process that

293
00:12:28.750 --> 00:12:31.590
turns the lunar soil over, churning buried

294
00:12:31.590 --> 00:12:34.550
material up and fresh material down. And

295
00:12:34.550 --> 00:12:36.830
he drew the conclusion people always want

296
00:12:36.830 --> 00:12:39.510
drawn on that turnover rate. The

297
00:12:39.510 --> 00:12:41.750
Apollo footprints will, in his words,

298
00:12:41.910 --> 00:12:44.550
definitely be long gone in about

299
00:12:44.550 --> 00:12:45.270
80,000

300
00:12:45.350 --> 00:12:48.270
Anna: years, which is not soon. But it

301
00:12:48.270 --> 00:12:49.510
is not forever either.

302
00:12:49.910 --> 00:12:51.510
Avery: That is the thing to take away.

303
00:12:52.070 --> 00:12:54.870
We talk about the moon as the dead unchanging

304
00:12:54.870 --> 00:12:57.760
one, the place where nothing happens. It

305
00:12:57.760 --> 00:13:00.760
is not unchanging. It is changing slowly

306
00:13:00.760 --> 00:13:03.320
and it changed in a big way two years ago.

307
00:13:03.560 --> 00:13:06.000
And the only reason we know is that there is

308
00:13:06.000 --> 00:13:08.400
a spacecraft up there photographing the same

309
00:13:08.400 --> 00:13:11.200
ground over and over. Take the watcher

310
00:13:11.200 --> 00:13:13.130
away and this simply would not be a, ah,

311
00:13:13.200 --> 00:13:13.800
known event.

312
00:13:14.360 --> 00:13:17.320
Anna: Okay, now on to our next storey. This one

313
00:13:17.320 --> 00:13:19.720
is a detective storey and it has an

314
00:13:19.720 --> 00:13:22.210
Australian fingerprint on it for

315
00:13:22.210 --> 00:13:25.130
178 years. The textbook answer

316
00:13:25.130 --> 00:13:27.930
to when did space weather first disrupt

317
00:13:27.930 --> 00:13:30.834
human Technology has been 18

318
00:13:31.026 --> 00:13:33.490
October 1841 in

319
00:13:33.490 --> 00:13:36.330
Devon, in the southwest of England. A

320
00:13:36.330 --> 00:13:38.690
train leaving Exeter at 5 past 10 at night

321
00:13:38.690 --> 00:13:41.370
was held for 16 minutes because the

322
00:13:41.370 --> 00:13:43.570
railway telegraph between Exeter and the

323
00:13:43.570 --> 00:13:45.890
village of Starcross had stopped working

324
00:13:46.290 --> 00:13:48.770
and the signalman could not confirm the line

325
00:13:48.770 --> 00:13:49.570
ahead was clear.

326
00:13:50.360 --> 00:13:51.320
Avery: Sixteen minutes.

327
00:13:51.640 --> 00:13:53.160
Hardly a catastrophe.

328
00:13:53.400 --> 00:13:56.360
Anna: Hardly a catastrophe. And that is precisely

329
00:13:56.360 --> 00:13:59.240
why it is famous. It is the first time we can

330
00:13:59.240 --> 00:14:01.360
point at a piece of critical infrastructure

331
00:14:01.360 --> 00:14:04.320
and say the sun did that. Trains

332
00:14:04.320 --> 00:14:06.640
stopped because of something happening 93

333
00:14:06.640 --> 00:14:09.320
million miles away and the people involved

334
00:14:09.320 --> 00:14:12.040
had no idea. It is quoted in review

335
00:14:12.040 --> 00:14:14.360
papers, in government resilience reports,

336
00:14:14.760 --> 00:14:17.670
in lectures. 1841 is the

337
00:14:17.670 --> 00:14:20.510
date everyone uses yesterday in the

338
00:14:20.510 --> 00:14:23.470
Journal Space Weather. A team led by Jim Wild

339
00:14:23.470 --> 00:14:26.310
at Lancaster University, with Brett Carter at

340
00:14:26.310 --> 00:14:28.910
RMIT in Melbourne, Mike Hapgood at

341
00:14:28.910 --> 00:14:31.470
RAL Space and colleagues at the British

342
00:14:31.470 --> 00:14:34.230
Geological Survey, Natural Resources Canada

343
00:14:34.230 --> 00:14:37.230
and Baylor published the correction. It

344
00:14:37.230 --> 00:14:40.150
did not happen in 1841. It happened on

345
00:14:40.150 --> 00:14:41.685
the 18th of October

346
00:14:41.875 --> 00:14:44.250
Avery: 1848, seven years out.

347
00:14:44.650 --> 00:14:47.130
How does a date like that survive a century

348
00:14:47.130 --> 00:14:47.850
and a half?

349
00:14:48.010 --> 00:14:50.850
Anna: Because nobody went back to the source. The

350
00:14:50.850 --> 00:14:53.490
original account is an anonymous article in

351
00:14:53.490 --> 00:14:56.376
the journal nature, published in 1871,

352
00:14:56.564 --> 00:14:59.490
30 years after the fact. And the

353
00:14:59.490 --> 00:15:01.850
giveaway, once you look, is almost

354
00:15:01.850 --> 00:15:04.850
embarrassing. The railway line between Exeter

355
00:15:04.850 --> 00:15:07.610
and Star Cross did not open until 1846.

356
00:15:08.200 --> 00:15:09.800
The event could not have happened on the line

357
00:15:09.800 --> 00:15:12.800
in 1841, because in 1841 there was

358
00:15:12.800 --> 00:15:13.400
no line.

359
00:15:14.280 --> 00:15:15.800
Avery: So it is a typo.

360
00:15:16.200 --> 00:15:18.920
Anna: It looks like a typo. 1848

361
00:15:18.920 --> 00:15:21.000
misprinted as 1841,

362
00:15:21.480 --> 00:15:23.680
probably by the anonymous author, who the

363
00:15:23.680 --> 00:15:25.920
team think was most likely Nathaniel John

364
00:15:25.920 --> 00:15:28.520
Holmes, a telegraph engineer of the period.

365
00:15:29.160 --> 00:15:31.720
But proving that took real archival work

366
00:15:32.040 --> 00:15:34.330
and this is the part I enjoyed. They went

367
00:15:34.330 --> 00:15:36.810
through old railway timetables to find when a

368
00:15:36.810 --> 00:15:39.130
five past ten evening service from Exeter

369
00:15:39.130 --> 00:15:41.930
actually existed, which narrowed it to a four

370
00:15:41.930 --> 00:15:44.370
month window. They pulled the magnetic

371
00:15:44.370 --> 00:15:46.930
observatory records from Greenwich. They read

372
00:15:46.930 --> 00:15:49.130
the sunspot drawings. They went through

373
00:15:49.130 --> 00:15:51.494
newspaper archives and 18

374
00:15:51.646 --> 00:15:53.770
October 1848 lights up

375
00:15:54.090 --> 00:15:56.370
Greenwich recorded powerful magnetic

376
00:15:56.370 --> 00:15:58.610
disturbance from about 20 past 9 in the

377
00:15:58.610 --> 00:16:01.220
evening Universal Time. There were

378
00:16:01.220 --> 00:16:03.220
aurora sightings right across the United

379
00:16:03.220 --> 00:16:05.780
Kingdom. And there was a large sunspot group

380
00:16:05.780 --> 00:16:08.460
on the disc recorded from Durham. The

381
00:16:08.460 --> 00:16:10.900
timetable, the magnetometer, the aurora

382
00:16:10.900 --> 00:16:13.620
reports and the sunspot all agree on one

383
00:16:13.620 --> 00:16:13.940
night.

384
00:16:14.420 --> 00:16:17.300
Avery: Mike Hapgood had a line about that he

385
00:16:17.300 --> 00:16:18.500
did quote.

386
00:16:18.980 --> 00:16:21.300
Anna: Our research has a hint of a Detective Storey

387
00:16:21.780 --> 00:16:24.060
piecing together a wide range of archived

388
00:16:24.060 --> 00:16:26.140
records to better understand a historically

389
00:16:26.140 --> 00:16:27.620
severe space weather event.

390
00:16:28.220 --> 00:16:30.780
End quote. And there is a reason this matters

391
00:16:30.780 --> 00:16:32.620
beyond tidying up. A footnote.

392
00:16:33.020 --> 00:16:35.980
1848 is 11 years before the Carrington

393
00:16:35.980 --> 00:16:38.780
event of 1859, which is the storm

394
00:16:38.780 --> 00:16:41.500
everyone uses as the worst case. Redating

395
00:16:41.500 --> 00:16:44.099
this one does not just move a date, it puts a

396
00:16:44.099 --> 00:16:46.620
severe infrastructure affecting storm into

397
00:16:46.620 --> 00:16:48.540
the record in a decade where we thought we

398
00:16:48.540 --> 00:16:51.260
had one. How often the really big storms

399
00:16:51.260 --> 00:16:53.620
happen is a question we answer by counting

400
00:16:53.620 --> 00:16:55.990
them in the historical record. And the

401
00:16:55.990 --> 00:16:57.910
historical record is only as good as the

402
00:16:57.910 --> 00:16:59.670
record keeping, which is

403
00:16:59.670 --> 00:17:01.830
Avery: the same trap we keep running into with

404
00:17:01.830 --> 00:17:02.670
catalogues.

405
00:17:03.230 --> 00:17:05.790
Anna: It is exactly the same trap moved from

406
00:17:05.790 --> 00:17:08.790
telescopes to archives and it sits squarely

407
00:17:08.790 --> 00:17:10.830
in a thread we have been pulling all month.

408
00:17:11.230 --> 00:17:13.430
The superflare potential work back On

409
00:17:13.430 --> 00:17:16.310
Saturday the 12th, the cosmic radiation at

410
00:17:16.310 --> 00:17:17.430
aviation altitudes.

411
00:17:17.430 --> 00:17:19.950
On Monday the 14th, same dial.

412
00:17:20.510 --> 00:17:22.630
Jim Wilde's closing thought is the one to

413
00:17:22.630 --> 00:17:25.490
keep Space weather is not a

414
00:17:25.490 --> 00:17:27.490
new threat, but a long standing natural

415
00:17:27.490 --> 00:17:30.170
hazard. Society has been experiencing the

416
00:17:30.170 --> 00:17:32.570
effects of space weather on technology for

417
00:17:32.570 --> 00:17:34.690
almost as long as electrical technologies

418
00:17:34.690 --> 00:17:37.650
have existed. End quote. The Victorians

419
00:17:37.650 --> 00:17:39.970
were not protected from the sun. They just

420
00:17:39.970 --> 00:17:40.850
had less to lose.

421
00:17:41.010 --> 00:17:43.650
Avery: In February 1996, a

422
00:17:43.650 --> 00:17:46.330
Japanese amateur astronomer named Yukio

423
00:17:46.330 --> 00:17:48.530
Sakurai found a new star in

424
00:17:48.530 --> 00:17:51.120
Sagittarius. It was announced through the

425
00:17:51.120 --> 00:17:53.800
usual channel, an IAU circular

426
00:17:53.880 --> 00:17:56.800
on 23 February. At first

427
00:17:56.800 --> 00:17:58.760
everyone assumed it was a nova.

428
00:17:59.160 --> 00:17:59.960
Anna: It wasn't.

429
00:18:00.680 --> 00:18:03.320
Avery: No, it certainly wasn't. What

430
00:18:03.320 --> 00:18:05.600
Sakurai had found was one of the rarest

431
00:18:05.600 --> 00:18:08.520
events in stellar astrophysics. A

432
00:18:08.520 --> 00:18:10.960
star that had already died coming back to

433
00:18:10.960 --> 00:18:13.080
life. It is catalogued as

434
00:18:13.080 --> 00:18:14.920
V4334

435
00:18:14.920 --> 00:18:17.480
Sagittarius and everybody calls it

436
00:18:17.480 --> 00:18:20.440
Sakurai's object. Yesterday, a

437
00:18:20.440 --> 00:18:23.280
team led by Albert Zylstra at the Jodrell

438
00:18:23.280 --> 00:18:25.680
Bank Centre for Astrophysics in Manchester,

439
00:18:25.840 --> 00:18:28.800
with Peter Van Hoof at the Royal Observatory

440
00:18:28.800 --> 00:18:31.400
of Belgium and colleagues at the Valongo

441
00:18:31.400 --> 00:18:34.200
Observatory in Rio de Janeiro published

442
00:18:34.200 --> 00:18:36.920
new measurements of it in monthly notices of

443
00:18:36.920 --> 00:18:39.880
the Royal Astronomical Society. And the

444
00:18:39.880 --> 00:18:42.760
number is. In 30 years, the

445
00:18:42.830 --> 00:18:45.470
the star has become about six times hotter.

446
00:18:45.790 --> 00:18:48.510
Its surface was sun like when Sakurai found

447
00:18:48.510 --> 00:18:50.510
it. It is now somewhere between

448
00:18:50.750 --> 00:18:53.390
27,000 and 36,000

449
00:18:53.470 --> 00:18:56.270
kelvin. That is among the fastest heating

450
00:18:56.270 --> 00:18:58.430
rates ever measured on any star.

451
00:18:59.150 --> 00:19:01.150
Anna: Take us through what actually happened to it.

452
00:19:01.790 --> 00:19:04.630
Avery: So this star had finished. It had been a sun

453
00:19:04.630 --> 00:19:07.150
like star. It had run through its fuel,

454
00:19:07.310 --> 00:19:09.750
blown off its outer layers and and settled

455
00:19:09.750 --> 00:19:12.710
down to be a white dwarf, an inert cooling

456
00:19:12.710 --> 00:19:15.310
cinder that is meant to be the end.

457
00:19:15.630 --> 00:19:17.950
But there was still a thin layer of helium

458
00:19:17.950 --> 00:19:20.670
sitting on top of the carbon and oxygen core.

459
00:19:20.750 --> 00:19:23.590
And that layer reignited one

460
00:19:23.590 --> 00:19:26.550
last shell flash after the star had already

461
00:19:26.550 --> 00:19:29.270
become a white dwarf. The technical

462
00:19:29.270 --> 00:19:32.270
term is a very late thermal pulse and

463
00:19:32.270 --> 00:19:34.790
the effect is dramatic. The star

464
00:19:34.790 --> 00:19:37.750
puffs back up into a giant in years rather

465
00:19:37.750 --> 00:19:40.690
than millennia. It ends up hydrogen poor

466
00:19:40.690 --> 00:19:43.650
and enriched in helium and carbon because

467
00:19:43.650 --> 00:19:46.370
the flash has dragged process material up

468
00:19:46.370 --> 00:19:49.370
from deep inside. Astronomers call these

469
00:19:49.370 --> 00:19:52.330
born again stars and we know of only

470
00:19:52.330 --> 00:19:53.130
a handful.

471
00:19:53.690 --> 00:19:54.809
Anna: And then it vanished.

472
00:19:54.809 --> 00:19:57.730
Avery: Didn't, did. And that is the

473
00:19:57.730 --> 00:20:00.450
frustrating part of the storey. By late

474
00:20:00.450 --> 00:20:03.370
1998 the Star had manufactured

475
00:20:03.370 --> 00:20:05.560
so much carbon dust that that it wrapped

476
00:20:05.560 --> 00:20:07.880
itself in an opaque shell and by

477
00:20:07.880 --> 00:20:10.640
1999 it had disappeared from

478
00:20:10.640 --> 00:20:12.560
optical telescopes entirely.

479
00:20:13.200 --> 00:20:15.640
Imagine watching the one event you have been

480
00:20:15.640 --> 00:20:18.440
waiting a career for and the object pulls a

481
00:20:18.440 --> 00:20:21.240
curtain across itself. What this team has

482
00:20:21.240 --> 00:20:23.720
done is get back in. They used

483
00:20:23.720 --> 00:20:26.720
ESO's Very Large Telescope in Chile for

484
00:20:26.720 --> 00:20:29.600
spectroscopy. They used ALMA, and

485
00:20:29.600 --> 00:20:32.120
they compared what they saw against models

486
00:20:32.120 --> 00:20:35.020
built for Wolf Rayet stars, the hot

487
00:20:35.100 --> 00:20:37.900
stripped, fiercely windy stars that show

488
00:20:37.900 --> 00:20:40.300
strong carbon and helium signatures.

489
00:20:40.620 --> 00:20:43.460
And that is what Sakurai's object now looks

490
00:20:43.460 --> 00:20:46.180
like. The paper's title says the

491
00:20:46.180 --> 00:20:48.380
emergence of a WC star in

492
00:20:48.380 --> 00:20:51.380
Sakurai's object. Astronomers write it

493
00:20:51.380 --> 00:20:53.980
in square brackets, which is the notation for

494
00:20:53.980 --> 00:20:56.940
the low mass version. It has the spectrum of

495
00:20:56.940 --> 00:20:59.740
a Wolf Rayet star without being a massive

496
00:20:59.740 --> 00:21:00.700
star at all.

497
00:21:01.590 --> 00:21:02.710
Anna: So the curtain is thinning.

498
00:21:02.870 --> 00:21:05.310
Avery: You could say that. And the star underneath

499
00:21:05.310 --> 00:21:07.590
is a different star from the one that went

500
00:21:07.590 --> 00:21:08.310
behind it.

501
00:21:08.630 --> 00:21:11.270
And the headline result is a disagreement

502
00:21:11.270 --> 00:21:13.670
with theory, which is the useful kind of

503
00:21:13.670 --> 00:21:16.470
result. Zelstra's team find it is

504
00:21:16.470 --> 00:21:18.750
reheating more gradually than some of the

505
00:21:18.750 --> 00:21:21.670
newer models predicted. That is a direct

506
00:21:21.750 --> 00:21:24.710
constraint on how convection and mixing work

507
00:21:24.790 --> 00:21:27.660
inside a star during a shell flash, a

508
00:21:27.660 --> 00:21:30.420
process we normally can only model because it

509
00:21:30.420 --> 00:21:33.260
takes longer than a civilization. Here

510
00:21:33.260 --> 00:21:36.260
it takes about as long as a career. One

511
00:21:36.260 --> 00:21:39.260
honest caveat. The distance to this object

512
00:21:39.260 --> 00:21:41.180
is genuinely poorly known.

513
00:21:41.820 --> 00:21:44.140
Published estimates run from under 2

514
00:21:44.140 --> 00:21:47.140
kiloparsecs to more than 5, which is a

515
00:21:47.140 --> 00:21:50.140
factor of nearly 3. And distance feeds

516
00:21:50.140 --> 00:21:53.100
into luminosity. The temperature measurement

517
00:21:53.100 --> 00:21:55.600
does not depend on it. That comes from the

518
00:21:55.600 --> 00:21:56.200
spectrum.

519
00:21:56.280 --> 00:21:58.840
But be wary of any brightness figure

520
00:21:58.840 --> 00:22:01.360
quoted to more precision than that spread

521
00:22:01.360 --> 00:22:02.040
allows.

522
00:22:02.680 --> 00:22:03.880
Anna: And where is it headed?

523
00:22:04.440 --> 00:22:06.800
Avery: Back where it came from. It will keep

524
00:22:06.800 --> 00:22:09.480
heating, blow away what is left and

525
00:22:09.560 --> 00:22:12.040
settle down to being a white dwarf again.

526
00:22:12.360 --> 00:22:14.520
The same fate reached twice.

527
00:22:15.080 --> 00:22:17.840
Peter van Hoof's summary is the one to end

528
00:22:17.840 --> 00:22:20.680
on. Sakurai's

529
00:22:20.680 --> 00:22:23.000
object offers something far rarer.

530
00:22:23.560 --> 00:22:26.160
It is one of the very few stars known to have

531
00:22:26.160 --> 00:22:28.480
changed dramatically within just a few

532
00:22:28.480 --> 00:22:31.320
decades, end quote. Most

533
00:22:31.320 --> 00:22:34.080
of stellar evolution is a slideshow. We get

534
00:22:34.080 --> 00:22:37.000
one frame of this one is a film.

535
00:22:37.640 --> 00:22:39.640
Anna: A quick update on a storey we left

536
00:22:39.640 --> 00:22:42.440
deliberately unfinished Back On Monday

537
00:22:42.440 --> 00:22:45.200
the 14th we told you Crew 13 had been

538
00:22:45.200 --> 00:22:47.920
stood down, that the cause was an oxidizer

539
00:22:47.920 --> 00:22:49.880
leak found in Dragon's propulsion system

540
00:22:50.350 --> 00:22:52.550
during pre launch processing. That the

541
00:22:52.550 --> 00:22:55.070
Canadian Space Agency had said late September

542
00:22:55.230 --> 00:22:57.950
and that NASA had published no specific date.

543
00:22:58.350 --> 00:23:00.790
We said on air that the absence of a date was

544
00:23:00.790 --> 00:23:01.710
itself the news.

545
00:23:02.510 --> 00:23:04.030
Avery: And now there is one.

546
00:23:04.590 --> 00:23:05.790
Anna: Now there is a window.

547
00:23:06.109 --> 00:23:08.910
NASA's station blog updated yesterday says

548
00:23:08.910 --> 00:23:11.550
the oxidizer valve has been replaced and that

549
00:23:11.550 --> 00:23:14.550
NASA and SpaceX are targeting quote as

550
00:23:14.550 --> 00:23:17.230
soon as early October end quote for the

551
00:23:17.230 --> 00:23:19.670
launch. The extra time is for pre launch

552
00:23:19.670 --> 00:23:21.910
activities. Readiness reviews and

553
00:23:21.910 --> 00:23:24.790
coordinating with station operations. So

554
00:23:24.950 --> 00:23:27.390
still not a calendar date, but a valve that

555
00:23:27.390 --> 00:23:29.310
has been fixed rather than a leak being

556
00:23:29.310 --> 00:23:31.830
investigated and a month you can plan around.

557
00:23:32.390 --> 00:23:34.990
The crew is unchanged. Jessica Watkins

558
00:23:34.990 --> 00:23:37.910
commanding, Luke Delaney as pilot, Joshua

559
00:23:37.910 --> 00:23:40.550
Kutryk for the Canadian Space agency and

560
00:23:40.550 --> 00:23:43.110
Sergey to Teriatnikov for Roscosmos

561
00:23:43.620 --> 00:23:46.180
on a Falcon 9 from Space Launch Complex 40.

562
00:23:46.900 --> 00:23:49.420
Avery: And the station is not going hungry in the

563
00:23:49.420 --> 00:23:51.140
meantime, it is not.

564
00:23:51.700 --> 00:23:54.500
Anna: Progress 96 launched yesterday morning US

565
00:23:54.580 --> 00:23:57.220
time with nearly three tonnes of food,

566
00:23:57.540 --> 00:24:00.380
fuel and cargo for the Expedition 75

567
00:24:00.380 --> 00:24:03.020
crew. And it docks to the POISK module on

568
00:24:03.020 --> 00:24:03.300
Saturday.

569
00:24:03.700 --> 00:24:06.620
Avery: Right, what to actually go outside and look

570
00:24:06.620 --> 00:24:06.900
at.

571
00:24:07.140 --> 00:24:09.660
And there is a genuine event on the calendar

572
00:24:09.660 --> 00:24:12.630
for tomorrow night. Friday the 18th

573
00:24:12.870 --> 00:24:15.590
Venus reaches greatest brilliancy.

574
00:24:15.910 --> 00:24:18.510
That is the single brightest Venus gets in

575
00:24:18.510 --> 00:24:21.350
this entire evening apparition at about

576
00:24:21.430 --> 00:24:24.190
magnitude -4.8. And

577
00:24:24.190 --> 00:24:27.030
tonight it is already within a whisker of it.

578
00:24:27.270 --> 00:24:30.150
So do not wait for permission. The reason the

579
00:24:30.150 --> 00:24:32.950
peak falls now rather than when Venus is

580
00:24:32.950 --> 00:24:35.750
closest or when Venus is fullest, is

581
00:24:35.750 --> 00:24:38.740
worth 30 seconds because it is a lovely bit

582
00:24:38.740 --> 00:24:39.660
of geometry.

583
00:24:40.220 --> 00:24:41.420
Anna: It is a trade off.

584
00:24:41.900 --> 00:24:44.900
Avery: It is exactly a trade off. Brightness is

585
00:24:44.900 --> 00:24:47.900
lit fraction times disc size. As

586
00:24:47.900 --> 00:24:50.780
Venus swings round toward us, it gets bigger.

587
00:24:51.020 --> 00:24:54.020
The disc is now about 39 arc seconds

588
00:24:54.020 --> 00:24:56.740
across, which is enormous, roughly

589
00:24:56.740 --> 00:24:59.140
three times the size it was at the start of

590
00:24:59.140 --> 00:25:01.900
the apparition. But as it comes toward us,

591
00:25:01.900 --> 00:25:04.810
we also see less of its lit face. It

592
00:25:04.810 --> 00:25:07.650
is only about 26% illuminated.

593
00:25:07.890 --> 00:25:10.650
A big thin crescent beats a small full

594
00:25:10.650 --> 00:25:13.570
disc. And tomorrow night the two curves

595
00:25:13.570 --> 00:25:14.050
cross.

596
00:25:14.450 --> 00:25:17.010
Put a pair of binoculars on it, steadied

597
00:25:17.010 --> 00:25:19.610
against a fence or a door frame, and the

598
00:25:19.610 --> 00:25:22.570
crescent shape is obvious. That is not a

599
00:25:22.570 --> 00:25:25.170
subtle target. One note on the date.

600
00:25:25.490 --> 00:25:28.330
Some listings give 22 September for

601
00:25:28.330 --> 00:25:30.690
greatest brilliancy. On a slightly different

602
00:25:30.690 --> 00:25:33.030
definition, we are using the

603
00:25:33.030 --> 00:25:33.750
18th.

604
00:25:33.990 --> 00:25:36.630
The difference is a definition, not a

605
00:25:36.630 --> 00:25:39.390
disagreement about Venus. And either way,

606
00:25:39.390 --> 00:25:41.830
this week and next are spectacular.

607
00:25:42.470 --> 00:25:45.110
Now, where you are standing decides how good

608
00:25:45.110 --> 00:25:48.030
a night you have. And the gap is enormous.

609
00:25:48.030 --> 00:25:50.910
Right now. From Sydney, the Sun sets

610
00:25:50.910 --> 00:25:53.790
at 11 minutes to 6 and Venus is

611
00:25:53.790 --> 00:25:56.670
39 degrees above the western horizon at

612
00:25:56.670 --> 00:25:59.500
that moment, most of the way from the horizon

613
00:25:59.500 --> 00:26:02.140
to overhead. It does not set until

614
00:26:02.220 --> 00:26:05.060
three minutes past nine. That is three

615
00:26:05.060 --> 00:26:08.060
and a quarter hours of Venus after sunset.

616
00:26:08.300 --> 00:26:11.100
Melbourne, Brisbane, Perth, Auckland,

617
00:26:11.260 --> 00:26:14.220
Cape Town, Santiago, same storey.

618
00:26:15.100 --> 00:26:17.100
Anna: And for our, uh, North American listeners,

619
00:26:17.260 --> 00:26:19.180
who are the biggest part of this audience,

620
00:26:20.060 --> 00:26:21.340
considerably tougher.

621
00:26:21.580 --> 00:26:24.060
Avery: And I am not going to pretend otherwise.

622
00:26:24.720 --> 00:26:27.640
From Los angeles, Venus is 14 degrees

623
00:26:27.640 --> 00:26:30.360
up at sunset and sets an hour and

624
00:26:30.360 --> 00:26:33.320
20 minutes later from New York, 10

625
00:26:33.320 --> 00:26:35.600
degrees and an hour and five

626
00:26:36.240 --> 00:26:39.040
from London, three degrees and half an

627
00:26:39.040 --> 00:26:42.000
hour. Genuinely difficult. This is the

628
00:26:42.000 --> 00:26:44.920
ecliptic tilt again and it is at its most

629
00:26:44.920 --> 00:26:47.520
extreme in the weeks around the equinox.

630
00:26:47.840 --> 00:26:50.240
The line the planets follow stands almost

631
00:26:50.320 --> 00:26:52.880
vertically up from the western horizon at

632
00:26:52.880 --> 00:26:55.250
dusk from the southern hemisphere and, and

633
00:26:55.250 --> 00:26:57.930
lies almost flat along it from the northern.

634
00:26:58.490 --> 00:27:01.210
Same planet, same evening, radically

635
00:27:01.210 --> 00:27:02.490
different altitude.

636
00:27:03.050 --> 00:27:05.210
Anna: So what is the practical advice up north?

637
00:27:05.450 --> 00:27:08.370
Avery: Find a clear western horizon, the sea,

638
00:27:08.370 --> 00:27:11.290
a lake, a ridge with nothing on it. And

639
00:27:11.290 --> 00:27:14.250
look 20 to 45 minutes after sunset.

640
00:27:14.890 --> 00:27:16.970
Venus is bright enough to punch through

641
00:27:16.970 --> 00:27:19.530
twilight and you will not mistake it for

642
00:27:19.530 --> 00:27:22.240
anything else. It is worth the effort.

643
00:27:22.560 --> 00:27:25.200
You just cannot be casual about it the way we

644
00:27:25.200 --> 00:27:28.200
can down here. Mercury is the harder

645
00:27:28.200 --> 00:27:31.080
version of the same lesson. From Sydney,

646
00:27:31.080 --> 00:27:33.680
it is 15 degrees up, uh, at sunset,

647
00:27:33.920 --> 00:27:36.800
a genuinely good apparition. And it sets

648
00:27:36.800 --> 00:27:38.960
an hour and a quarter after the Sun.

649
00:27:39.600 --> 00:27:42.560
From Los angeles, it is 8 degrees. From

650
00:27:42.560 --> 00:27:44.960
New York, six from London, three

651
00:27:45.680 --> 00:27:48.020
Southern. Listeners, this is your

652
00:27:48.020 --> 00:27:50.860
Mercury. It sits below and to the

653
00:27:50.860 --> 00:27:53.780
right of Venus, about 24 degrees away

654
00:27:54.500 --> 00:27:56.900
then the Moon. And this is where both

655
00:27:56.900 --> 00:27:58.740
hemispheres get the same present.

656
00:27:59.300 --> 00:28:01.860
It is a fat Crescent tonight, about

657
00:28:01.860 --> 00:28:04.260
37% lit, going to

658
00:28:04.260 --> 00:28:07.060
47% tomorrow. And first quarter

659
00:28:07.140 --> 00:28:09.980
falls on Friday the 18th at 43

660
00:28:09.980 --> 00:28:12.740
minutes past 8 in the evening, universal

661
00:28:12.740 --> 00:28:15.390
time, which is quarter to 7 on Saturday

662
00:28:15.550 --> 00:28:18.550
morning here in Sydney. And that timing

663
00:28:18.550 --> 00:28:21.190
is not an accident because Saturday the

664
00:28:21.190 --> 00:28:24.150
19th is international. Observe the Moon

665
00:28:24.150 --> 00:28:26.190
night, which is deliberately

666
00:28:26.190 --> 00:28:27.390
Anna: scheduled for this phase.

667
00:28:27.470 --> 00:28:29.870
Avery: Deliberately and for the right reason.

668
00:28:30.270 --> 00:28:32.830
A full moon is a flat, glaring,

669
00:28:32.830 --> 00:28:35.510
shadowless disc and it is the worst night of

670
00:28:35.510 --> 00:28:38.030
the month to look at it. At first quarter,

671
00:28:38.110 --> 00:28:40.990
the terminator, the line between lunar day

672
00:28:40.990 --> 00:28:43.630
and lunar night, runs straight down the

673
00:28:43.630 --> 00:28:46.550
middle. The sunlight comes in almost sideways

674
00:28:46.790 --> 00:28:49.630
and every crater, rim and mountain throws

675
00:28:49.630 --> 00:28:52.430
a long shadow. Through even the smallest

676
00:28:52.430 --> 00:28:53.110
telescope.

677
00:28:53.110 --> 00:28:55.870
The Moon stops being a picture and becomes a

678
00:28:55.870 --> 00:28:58.470
landscape. And in the light of our second

679
00:28:58.550 --> 00:29:01.390
storey, have a look at Mare Chrisium, the

680
00:29:01.390 --> 00:29:04.110
dark oval near the eastern limb. It is

681
00:29:04.110 --> 00:29:07.100
obvious in binoculars. Somewhere out on

682
00:29:07.100 --> 00:29:09.980
its outer ring, 20 kilometres east of Mare

683
00:29:09.980 --> 00:29:12.540
Spumans, is the crater that was not there

684
00:29:12.540 --> 00:29:15.380
before the middle of 2024. You

685
00:29:15.380 --> 00:29:18.260
will not see it. 200 metres is far

686
00:29:18.260 --> 00:29:20.580
below anything Earth based equipment can

687
00:29:20.580 --> 00:29:23.340
resolve. And at this phase that region is

688
00:29:23.340 --> 00:29:25.940
fully lit and flat, rather than sitting on

689
00:29:25.940 --> 00:29:28.300
the terminator. But you will be looking at

690
00:29:28.300 --> 00:29:30.940
the right patch of ground and knowing it is

691
00:29:30.940 --> 00:29:33.530
there changes what you are looking at. Before

692
00:29:33.530 --> 00:29:36.090
dawn, the balance flips and this one

693
00:29:36.090 --> 00:29:38.970
belongs to the North Jupiter Is the

694
00:29:38.970 --> 00:29:41.930
prize at the start of nautical Twilight.

695
00:29:42.090 --> 00:29:44.770
Jupiter is 26 degrees up from Los

696
00:29:44.770 --> 00:29:46.970
Angeles, 24 from New York,

697
00:29:47.450 --> 00:29:50.238
21 from London and only 8

698
00:29:50.342 --> 00:29:52.090
1/2 degrees from Sydney.

699
00:29:52.490 --> 00:29:55.330
Still fighting the horizon murk. Mars

700
00:29:55.330 --> 00:29:58.170
is even more lopsided, 48 degrees

701
00:29:58.170 --> 00:30:01.030
up from Los Angeles, 46 from New

702
00:30:01.030 --> 00:30:03.830
York, 40 from London against uh, 20

703
00:30:03.830 --> 00:30:06.590
from Sydney. Mars is faint at the

704
00:30:06.590 --> 00:30:09.430
moment, magnitude 1.2, an

705
00:30:09.430 --> 00:30:12.430
unremarkable orange dot, but the two are

706
00:30:12.430 --> 00:30:15.390
23 degrees apart and closing. They

707
00:30:15.390 --> 00:30:17.830
will be about 12 degrees apart by mid

708
00:30:17.830 --> 00:30:20.590
October and about 2 degrees apart by

709
00:30:20.590 --> 00:30:23.310
mid November. Start watching that gap

710
00:30:23.310 --> 00:30:25.750
now and the shrinking is the whole point.

711
00:30:26.490 --> 00:30:28.970
Saturn is well placed for everybody before

712
00:30:28.970 --> 00:30:31.690
dawn around 23 to 28

713
00:30:31.690 --> 00:30:34.610
degrees up wherever you are and it is worth

714
00:30:34.610 --> 00:30:37.250
getting familiar with because opposition is

715
00:30:37.250 --> 00:30:39.930
on the 4th of October rings about

716
00:30:39.930 --> 00:30:42.730
7 degrees open disc a uh touch

717
00:30:42.730 --> 00:30:45.610
under 20 arc seconds. One note for

718
00:30:45.610 --> 00:30:48.370
the southern zodiacal light hunters, not this

719
00:30:48.370 --> 00:30:51.170
week. The evening sky is moonlit from

720
00:30:51.170 --> 00:30:53.690
here through full moon on the 26th.

721
00:30:54.240 --> 00:30:57.240
That false dusk in the west. The faint cone

722
00:30:57.240 --> 00:30:59.880
of sunlight scattered off interplanetary

723
00:30:59.880 --> 00:31:02.360
dust which is an evening object from the

724
00:31:02.360 --> 00:31:05.040
southern hemisphere and a pre dawn object

725
00:31:05.040 --> 00:31:07.800
from the northern at this time of year comes

726
00:31:07.800 --> 00:31:10.480
back into play in the first week of October

727
00:31:10.800 --> 00:31:13.320
and the equinox Wednesday the

728
00:31:13.320 --> 00:31:16.200
23rd at five minutes past midnight

729
00:31:16.200 --> 00:31:18.760
Universal time which is the evening of

730
00:31:18.760 --> 00:31:21.760
Tuesday the 22nd across the Americas and

731
00:31:21.760 --> 00:31:24.160
mid morning on Wednesday here in Australia.

732
00:31:24.900 --> 00:31:27.620
It is an instant, not a day, so the date

733
00:31:27.620 --> 00:31:30.460
depends on where you are standing. Finally,

734
00:31:30.460 --> 00:31:33.060
and we say this every single episode for a

735
00:31:33.060 --> 00:31:35.940
reason, our space weather storey mentioned a

736
00:31:35.940 --> 00:31:37.900
big sunspot group visible in

737
00:31:37.900 --> 00:31:40.820
1848 and every time we mention

738
00:31:40.900 --> 00:31:43.860
sunspots someone quite reasonably wants to go

739
00:31:43.860 --> 00:31:46.820
and look. Do not point any telescope,

740
00:31:46.820 --> 00:31:49.660
any binoculars or any camera at the sun

741
00:31:49.660 --> 00:31:52.140
without a purpose built solar filter fitted

742
00:31:52.140 --> 00:31:54.600
over the front of the optics. If you are

743
00:31:54.600 --> 00:31:57.400
using eclipse glasses or a handheld solar

744
00:31:57.400 --> 00:31:59.880
viewer they must meet the ISO

745
00:31:59.880 --> 00:32:02.640
123122 international

746
00:32:02.960 --> 00:32:05.960
safety standard cheque for that marking and

747
00:32:05.960 --> 00:32:08.720
cheque the filter for scratches or pinholes

748
00:32:08.720 --> 00:32:10.320
before every single use.

749
00:32:10.960 --> 00:32:13.360
Sunglasses are not a solar filter.

750
00:32:13.840 --> 00:32:16.320
Exposed film, smoked glass and

751
00:32:16.320 --> 00:32:19.040
welding glass below shade 14 are

752
00:32:19.040 --> 00:32:21.940
not solar filters. Eye damage from the

753
00:32:21.940 --> 00:32:24.740
sun is painless and permanent and it does

754
00:32:24.740 --> 00:32:26.820
not announce itself until it is done.

755
00:32:26.980 --> 00:32:28.980
Anna: That is Astronomy AstroDailyPod for Thursday

756
00:32:29.140 --> 00:32:31.860
17th September. A

757
00:32:31.860 --> 00:32:34.380
planet under a million years old caught in

758
00:32:34.380 --> 00:32:37.020
the gap. It is carving a 200

759
00:32:37.020 --> 00:32:39.260
metre hole in the moon that nobody saw

760
00:32:39.260 --> 00:32:41.860
arrive. A Victorian train delay

761
00:32:41.860 --> 00:32:44.420
recovered from the wrong decade and a dead

762
00:32:44.420 --> 00:32:46.020
star getting hotter by the year.

763
00:32:47.000 --> 00:32:49.840
Avery: Show notes Sources and links for everything

764
00:32:49.840 --> 00:32:52.280
we have covered are at astronomydaily

765
00:32:52.600 --> 00:32:55.320
IO and there is a contact form there.

766
00:32:55.560 --> 00:32:57.680
Listener questions have started whole

767
00:32:57.680 --> 00:32:59.960
segments on this show, so use it.

768
00:33:00.520 --> 00:33:02.280
Anna: We are on x, Facebook,

769
00:33:02.760 --> 00:33:05.320
Instagram, TikTok and Tumblr.

770
00:33:05.560 --> 00:33:08.560
AstroDaily Pod Astronomy AstroDailyPod

771
00:33:08.560 --> 00:33:11.080
is part of the Bitesz.com podcast network

772
00:33:11.400 --> 00:33:12.520
produced in Sydney.

773
00:33:13.300 --> 00:33:14.260
Avery: I'm Avery.

774
00:33:14.260 --> 00:33:16.100
Anna: And I'm Anna. Clear Skies.

775
00:33:18.910 --> 00:33:19.100
Mhm.