A Nobel in Ice: Unveiling the Secrets of the IceCube Neutrino Observatory

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Anna: Hello and welcome back to Astronomy daily.

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It's Friday the 9th of October 2026.

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This is series five, episode 201.

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And I'm Anna.

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Avery: And, um, I'm Avery. It is very good to be

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back. We've been off air for a little over

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two weeks. Our producer, Huw, needed some

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time away for surgery and we're very glad to

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report that it went well and he's on the

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mend.

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Anna: Welcome back, Huw. And to everyone

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who wrote in over the past fortnight asking

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where we'd got to, thank you. It meant a lot

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to know you'd noticed we were gone.

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Avery: It really did. And there's plenty to catch up

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on today. A Nobel Prize for a

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telescope buried two kilometres down in

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Antarctic ice. The most distant fast

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radio burst ever pinned down. With a Sydney

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astronomer leading the paper, and a planet

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that may have been built from the ashes of a

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dead star.

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Anna: Plus everything that happened while we were

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away. Starship reaching orbit. Crew

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13 at the station. Everything. And the end of

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a story you, our listeners, asked us to

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follow.

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Avery: Let's go.

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Anna: On Tuesday, the Royal Swedish Academy of

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sciences awarded the 2026 Nobel

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Prize in Physics to one person, Frances

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Halsen of the University of Wisconsin,

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Madison, for decisive contributions to

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the IceCube Neutrino Observatory and

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the discovery of high energy neutrinos of

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astrophysical origin.

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Avery: Halsin is 82, born in

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Tinan in Belgium. In 1944,

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when the call came, he was travelling in

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Italy, giving talks. And the instrument

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he's being honoured for is one of the

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strangest telescopes ever built, because it

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has no mirror, no lens, and it sits

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at the bottom of the world. The problem?

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A messenger that won't stop.

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Anna: To see why it matters, start with the

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particle. A, uh, neutrino is almost

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nothing, nearly massless, no

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electric charge, and it barely interacts with

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anything. Roughly 65 billion of

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them from the sun pass through every square

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centimetre of you every second, about the

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size of your fingernail. And essentially none

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of them notice you're there.

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Avery: Which is exactly what makes them valuable.

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Light gets absorbed by dust, bent by magnetic

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fields, blocked by gas. Charged

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cosmic rays get deflected so badly we can't

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tell where they came from. A neutrino just

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keeps going in a straight line. So if you

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catch one, it points straight back at, uh,

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whatever made it.

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Anna: The catch is the catching. If

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almost nothing stops a neutrino, you need an

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enormous amount of material and the patience

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to wait for the rare one that does hit an

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atom. That's the problem. Halsin took on in

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1988, his idea

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Avery: was to use the ice at the South Pole. Very

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occasionally, a, ah, neutrino collides with

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an atomic nucleus in the ice and produces

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a charged particle that moves faster than

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light does in ice. That throws off a faint

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cone of blue lightcherenkov light.

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The same glow you see in the water around the

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nuclear reactor core.

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Anna: And the deep Antarctic ice is

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extraordinarily clear, dark and

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stable. So you drill holes,

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lower light sensors on cables, freeze them in

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and use a cubic kilometre of glacier as the

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detector.

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Avery: That's what IceCube is

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5,160 sensors

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on 86 cables sitting between

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1,450 and

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2,450 metres down near

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the Ahmanson Scott South Pole Station.

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It came out of an earlier, smaller experiment

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called Amanda, and it was completed in 2011.

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Anna: Hm. Here's the Part I. The overwhelming

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majority of what IceCube sees isn't cosmic

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neutrinos at all. It's particles from

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cosmic ray showers in the atmosphere above

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Antarcticamore than 100 million a

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day. One of the cleanest tricks for rejecting

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them is to look down. A particle track

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coming up through the Earth can only have

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been made by a neutrino, because nothing else

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can cross the planet.

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Avery: So the telescope at the South Pole uses the

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whole Earth as a filter, which means

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for that technique, its best view is of the

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northern sky, straight through the planet.

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The most southerly observatory on Earth

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looking north through rock.

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Anna: It's worth remembering how unlikely that

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sounded in 1988. Nobody had

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built a particle detector out of a natural

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glacier and the early prototype work in the

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ice was slow going. Halsin's own

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reaction to Tuesday's call was that it was a

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great surprise and he obviously

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didn't expect it. After nearly four

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decades of pushing the

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Avery: idea and the shape of the light tells you

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what happened. A neutrino that makes a

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muon leaves a long, straight track of light

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through the array. That's the one that points

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back well to its source. Other

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interactions make a roughly spherical flash,

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a cascade which measures the energy well, but

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the direction only roughly. Different

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events, different strengths. An ice cube uses

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both. Then there's the question it was

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really built for cosmic rays.

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Charged particles hitting Earth with enormous

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energies were discovered in 1912. And

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more than a century later, we still can't say

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for sure where the most energetic ones are

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accelerated. Wherever cosmic rays are being

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sped up and crash into gas or light, they

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make neutrinos. So find the neutrino

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sources and you've found the particle

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accelerators.

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Anna: And it worked. By 2013,

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two years into full operation, IceCube

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had collected 28 high energy events that

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couldn't be explained by the atmosphere. The

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first evidence of neutrinos from beyond the

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solar system. That's the discovery the prize

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names.

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Avery: Then it started pointing to sources. In

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September 2017, a single high

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energy neutrino triggered an alert, and

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telescopes found a Flaring Blazar

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TXS0506

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0.56 in the same patch of

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sky. In 2022,

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IceCube reported neutrinos from the active

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galaxy NGC 10, UM68.

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And in 2023, it mapped high energy

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neutrinos coming from the plane of our own

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Milky Way.

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Anna: That last one has a southern twist. The

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heart of our galaxy sits in the southern sky,

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which is exactly the part IceCube's track

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method struggles with, because those

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neutrinos come down through the ice along

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with all the atmospheric junk. The galactic

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plane result leaned on the cascade events

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instead and on, um, machine learning to pick

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them out.

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Avery: And NGC 1068 is a nice one

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for listeners. It's about 47 million

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light years away in Cetus the Whale,

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right on the celestial equator, so it can be

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found from both hemispheres. And it shares a

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constellation with Saturn this month. More,

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um, on that in Skywatch.

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Anna: Each of those opened a door optical

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astronomy can't. Neutrinos come from the

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deep interiors of the most violent places.

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The core of an active galaxy, the region

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close to a black hole, places light can't

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escape cleanly.

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Avery: Now, one thing we should say plainly, a Nobel

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in physics can go to, uh, at most, three

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people. And this year it went to one.

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IceCube itself is the work of a large

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international collaboration, plus the

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engineers who drilled it and the winter over

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crews who keep it running through the polar

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night when it's too cold for aircraft to

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land.

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Anna: And the committee said so the chair, Mark

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Pierce, put it this way. Halsin has

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led an international team of researchers and

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engineers who have provided us with a

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fantastic instrument. The prize is for the

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vision and the leadership. The instrument

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belongs to a lot of people.

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Avery: It also fits a lineage. Raymond

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Davis and Masatoshi Koshiba shared a

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Nobel in 2002 for catching neutrinos from

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the sun and from supernova

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1987a, the explosion in the Large

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Magellanic Cloud we talked about just a few

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weeks ago. Still the only supernova whose

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neutrinos we've ever detected. In

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2015, it was Takaki Kajita and

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Arthur McDonald for showing neutrinos change

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flavour.

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Anna: The next step is bigger ice.

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IceCube Gen 2 is planned at roughly 8 times

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the volume, and the field is no longer

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only in Antarctica. The KM3 net

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detectors on the floor of the Mediterranean

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use seawater the same way, and early

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last year that collaboration reported the

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most energetic neutrino yet seen.

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Avery: So from a 1988 proposal that sounded

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faintly absurd, let's turn a glacier into

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a telescope. We now have neutrino

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astronomy as a working branch of the science,

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with the southernmost lab on Earth at its

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centre.

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Anna: Congratulations to Frances Halsin and to

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everyone who has ever frozen a sensor into

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the ice at the pole.

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Avery: Avery from one kind of cosmic

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messenger to another In a story led out of

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Sydney, astronomers have pinned down the most

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distant fast radio burst yet seen, and

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the paper was published on Thursday in the

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journal Science, led by Manisha Kaleb of the

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University of Sydney.

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Anna: Quick refresher Fast radio bursts are

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flashes of radio emission lasting about a

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millisecond from far outside our galaxy.

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The first was found in 2007 in archival

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data from Parkes Moraing in New

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South Wales, and we still don't know for

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certain what makes them.

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Avery: This one, FRB2024O3

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04B, was caught on

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4th March 2024 by the Meer

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TRAP system on the Meerkat radio telescope in

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South Africa. The radio signal

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suggested it was extremely far away. The

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problem was that the world's largest ground

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based telescopes could see no galaxy at all

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at that precise spot.

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Anna: How can a radio flash tell you its distance?

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As, uh, the burst crosses space, free

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electrons slow the longer wavelength

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slightly, so the low frequencies arrive a

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fraction of a second late. That delay,

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the dispersion measure, grows with the amount

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of gas crossed. So with distance,

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the link between the two is called the

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McQuart relation, after JP McQuart of

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ICRAR Curtin, whose team pinned it

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down with Australia's ASCAP in 2020.

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This burst's dispersion measure was huge,

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around 2,300, which is why the team

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expected it to be so far away. So the

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team turned to the James Webb Space

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Telescope. Webb's camera found a faint

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galaxy in exactly the right place, and its

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spectrograph measured a redshift of

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2.148 light. That left when the

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universe was about 3 billion years old.

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Avery: And the host was a surprise. Most

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fast radio burst hosts are big star forming

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galaxies. This one is a small dwarf

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00:11:07.930 --> 00:11:10.730
galaxy about a thousand times less massive

267
00:11:10.730 --> 00:11:13.730
than expected, forming stars hard with

268
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most of its stars perhaps made within about

269
00:11:15.810 --> 00:11:16.930
30 million years.

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00:11:17.729 --> 00:11:20.530
Anna: That matters for the origin. One idea

271
00:11:20.530 --> 00:11:22.930
is that bursts come from merging neutron

272
00:11:22.930 --> 00:11:25.290
stars, but that takes billions of years to

273
00:11:25.290 --> 00:11:28.290
happen. Another is a young intensely

274
00:11:28.290 --> 00:11:31.180
magnetic neutron star, a magnetar, which

275
00:11:31.180 --> 00:11:34.060
can form fast. A young host fits the

276
00:11:34.060 --> 00:11:36.540
magnetar picture and Caleb says the team

277
00:11:36.540 --> 00:11:39.020
thinks a uh, merger origin for this burst is

278
00:11:39.020 --> 00:11:40.020
very unlikely.

279
00:11:40.500 --> 00:11:43.220
Avery: There's a bonus. A burst like this

280
00:11:43.220 --> 00:11:45.860
is a flashlight shining through everything

281
00:11:46.100 --> 00:11:48.820
between it and us. Its signal

282
00:11:48.820 --> 00:11:51.660
carries the imprints of a previously unknown

283
00:11:51.660 --> 00:11:54.420
galaxy cluster about three and a half

284
00:11:54.420 --> 00:11:57.290
billion light years away and of the

285
00:11:57.290 --> 00:11:58.690
nearby Virgo cluster.

286
00:11:59.170 --> 00:12:01.930
Anna: One thing to be clear about this is the peer

287
00:12:01.930 --> 00:12:04.490
reviewed version of a result first posted as

288
00:12:04.490 --> 00:12:07.170
a preprint in August last year and the record

289
00:12:07.170 --> 00:12:09.970
distance was reported then. What's new this

290
00:12:09.970 --> 00:12:12.530
week is publication in Science after review

291
00:12:12.930 --> 00:12:15.810
along with NASA's release. It's one burst

292
00:12:16.050 --> 00:12:18.290
and one burst doesn't settle the origin

293
00:12:18.290 --> 00:12:19.250
question for the whole

294
00:12:19.250 --> 00:12:21.810
Avery: population, but the team estimates

295
00:12:21.810 --> 00:12:24.210
meerkat could catch several bursts a year

296
00:12:24.210 --> 00:12:25.810
from beyond redshift 1.

297
00:12:26.670 --> 00:12:29.310
Meerkat is a precursor to the SKA

298
00:12:29.550 --> 00:12:32.070
and its low frequency sibling is going up in

299
00:12:32.070 --> 00:12:34.670
Western Australia. Expect more of these

300
00:12:35.310 --> 00:12:35.710
next.

301
00:12:35.950 --> 00:12:38.870
Anna: A cold case from the Hubble archive in

302
00:12:38.870 --> 00:12:41.510
1999 Hubble took an ultraviolet

303
00:12:41.510 --> 00:12:43.550
spectrum of a white dwarf called

304
00:12:43.550 --> 00:12:47.470
HS02090832

305
00:12:47.870 --> 00:12:50.030
about 270 light years away.

306
00:12:50.910 --> 00:12:53.910
It contained roughly 100 absorption features

307
00:12:53.910 --> 00:12:55.070
nobody could identify.

308
00:12:55.730 --> 00:12:58.050
Avery: Jamie Williams, a doctoral candidate at the

309
00:12:58.050 --> 00:13:00.050
University of Warwick, went back to that

310
00:13:00.050 --> 00:13:02.770
spectrum with an updated atomic database and

311
00:13:02.770 --> 00:13:04.810
found that many of the mystery lines matched

312
00:13:04.810 --> 00:13:07.490
niobium, an element never before seen in a

313
00:13:07.490 --> 00:13:09.810
white dwarf. The paper was published on

314
00:13:09.810 --> 00:13:11.330
Monday in Nature Astronomy.

315
00:13:11.890 --> 00:13:14.690
Anna: Why is niobium a clue? Elements

316
00:13:14.690 --> 00:13:17.370
heavier than iron mostly aren't forged in a

317
00:13:17.370 --> 00:13:20.210
star's core. Niobium is made in the

318
00:13:20.210 --> 00:13:22.970
late swollen stage of a dying sun like

319
00:13:22.970 --> 00:13:25.850
star and then expelled. And this star's

320
00:13:25.850 --> 00:13:28.450
surface is also rich in zinc and copper,

321
00:13:28.610 --> 00:13:30.850
while it's nearly bare of the silicon and

322
00:13:30.850 --> 00:13:33.410
iron you'd expect from an ordinary rocky

323
00:13:33.410 --> 00:13:33.810
planet.

324
00:13:33.810 --> 00:13:36.690
Avery: Falling in that contrast is the

325
00:13:36.690 --> 00:13:39.690
point astronomers have found plenty of so

326
00:13:39.690 --> 00:13:42.490
called polluted white dwarfs. Stars whose

327
00:13:42.490 --> 00:13:45.250
surfaces are dusted with the remains of rocky

328
00:13:45.250 --> 00:13:47.570
asteroids and planets from the original

329
00:13:47.570 --> 00:13:50.130
system. First generation debris with

330
00:13:50.130 --> 00:13:52.980
silicon and iron in it. This one's

331
00:13:52.980 --> 00:13:54.940
surface chemistry looks nothing like that.

332
00:13:55.420 --> 00:13:58.420
Anna: Then there's tess. Over four months it

333
00:13:58.420 --> 00:14:00.740
saw ah, the white dwarf's brightness wobble

334
00:14:00.740 --> 00:14:03.500
on a cycle of about 4.4 days.

335
00:14:03.980 --> 00:14:06.740
The team reads that as a Jupiter sized

336
00:14:06.740 --> 00:14:09.700
planet orbiting about 6 million kilometres

337
00:14:09.700 --> 00:14:12.700
out far closer than Mercury is to the Sun.

338
00:14:13.100 --> 00:14:15.300
Avery: Put it together. And the proposal is

339
00:14:15.300 --> 00:14:18.020
remarkable. The planet didn't survive from

340
00:14:18.020 --> 00:14:20.940
the system's birth. It formed afterwards out

341
00:14:20.940 --> 00:14:23.780
of material the star shed as it died. A

342
00:14:23.780 --> 00:14:26.500
second generation planet, the white

343
00:14:26.500 --> 00:14:29.060
dwarf, is still around 35,000 degrees.

344
00:14:29.540 --> 00:14:31.780
So it's stripping that planet's atmosphere.

345
00:14:31.860 --> 00:14:34.620
And the niobium rich gas is raining back

346
00:14:34.620 --> 00:14:36.900
down onto the star where Hubble saw it.

347
00:14:37.460 --> 00:14:39.940
Anna: If that sounds familiar, it's the flip side

348
00:14:39.940 --> 00:14:42.860
of a story we ran last month. Bataygin and

349
00:14:42.860 --> 00:14:45.020
colleagues arguing that when a star like the

350
00:14:45.020 --> 00:14:47.840
sun becomes a white dwarf, it its planets get

351
00:14:47.840 --> 00:14:50.760
scattered. This suggests a star's death can

352
00:14:50.760 --> 00:14:53.560
also build something new. Three

353
00:14:53.560 --> 00:14:55.920
caveats and the team states them itself.

354
00:14:56.640 --> 00:14:59.160
First, Williams says plainly it is not a

355
00:14:59.160 --> 00:15:01.320
confirmed planet. The test signal is

356
00:15:01.320 --> 00:15:03.880
indirect. Second, keeping the

357
00:15:03.880 --> 00:15:06.200
ejected material close enough to form a

358
00:15:06.200 --> 00:15:08.720
planet probably needs a companion star to

359
00:15:08.720 --> 00:15:11.560
pull it back. Third, this work was

360
00:15:11.560 --> 00:15:13.480
first presented as a conference poster in

361
00:15:13.480 --> 00:15:16.120
July last year. This week's news is the peer

362
00:15:16.120 --> 00:15:16.880
reviewed paper.

363
00:15:17.360 --> 00:15:19.600
Avery: Williams plans to use Hubble over the next

364
00:15:19.600 --> 00:15:21.480
several years to find out whether planets

365
00:15:21.480 --> 00:15:24.400
like this are rare or common. Either

366
00:15:24.400 --> 00:15:27.320
way, a 27 year old spectrum just told us

367
00:15:27.320 --> 00:15:30.320
something new. Now, while we were away,

368
00:15:30.720 --> 00:15:32.720
four stories we'd been following came to a

369
00:15:32.720 --> 00:15:34.560
head. So here's to catch up.

370
00:15:35.040 --> 00:15:38.040
Anna: First Starship Flight 14 launched from

371
00:15:38.040 --> 00:15:40.890
Starbase on 28 September late that

372
00:15:40.890 --> 00:15:43.290
evening in eastern Australia and became the

373
00:15:43.290 --> 00:15:45.890
first starship to reach orbit. It deployed

374
00:15:45.890 --> 00:15:48.770
26 of the larger Starlink V3 satellites,

375
00:15:48.770 --> 00:15:50.610
the first ever delivered to orbit by

376
00:15:50.610 --> 00:15:53.530
starship. It wasn't clean. One booster

377
00:15:53.530 --> 00:15:55.570
engine shut down on the way up and so did one

378
00:15:55.570 --> 00:15:57.970
of the ship's vacuum engines. The ship still

379
00:15:57.970 --> 00:16:00.010
had enough to fire one sea level engine and

380
00:16:00.010 --> 00:16:02.850
insert itself into orbit. But in SpaceX's

381
00:16:02.850 --> 00:16:04.930
words, out of an abundance of caution,

382
00:16:05.250 --> 00:16:07.570
controllers cut the planned roughly 10 hour

383
00:16:07.570 --> 00:16:10.260
mission short, fired the first ever Starship

384
00:16:10.260 --> 00:16:12.820
deorbit burn after about two orbits and

385
00:16:12.820 --> 00:16:14.660
brought it down in the northern Pacific a

386
00:16:14.660 --> 00:16:17.020
little over three hours after launch. Not off

387
00:16:17.020 --> 00:16:19.980
Chile as we previewed. So orbit achieved

388
00:16:19.980 --> 00:16:22.700
payload delivered and an engine reliability

389
00:16:22.700 --> 00:16:24.380
question to answer before flight 15.

390
00:16:25.100 --> 00:16:28.020
Avery: Second crew um, 13 after the

391
00:16:28.020 --> 00:16:29.900
oxidizer leak that uh, grounded it in

392
00:16:29.900 --> 00:16:32.300
September. Crew 13 launched on Thursday

393
00:16:32.380 --> 00:16:35.380
1 October from Cape Canaveral aboard the

394
00:16:35.380 --> 00:16:37.910
Dragon Grace and docked with the station the

395
00:16:37.910 --> 00:16:40.590
same evening. Commander Jessica Watkins

396
00:16:40.590 --> 00:16:43.230
became the first NASA astronaut to fly Dragon

397
00:16:43.230 --> 00:16:46.030
twice with Luke Delaney, Canada's

398
00:16:46.030 --> 00:16:48.470
Joshua Kutryk and Russia's Sergei

399
00:16:48.470 --> 00:16:49.230
Tetericio.

400
00:16:49.710 --> 00:16:52.670
Anna: Third juice ESA's Jupiter

401
00:16:52.670 --> 00:16:54.230
mission swung past at

402
00:16:54.230 --> 00:16:57.030
8,640 kilometres over the

403
00:16:57.030 --> 00:16:59.776
Indian Ocean on the 28th, gaining 3

404
00:16:59.844 --> 00:17:02.430
1/2 kilometres per second and bending its

405
00:17:02.430 --> 00:17:05.430
path by about 20 degrees. Its monitoring

406
00:17:05.430 --> 00:17:07.190
cameras sent back views of Africa,

407
00:17:07.830 --> 00:17:10.630
Madagascar and the moon. The high

408
00:17:10.630 --> 00:17:12.670
resolution science camera images are still

409
00:17:12.670 --> 00:17:15.470
being processed. One more Earth Flyby

410
00:17:15.470 --> 00:17:18.270
comes in January 2029, then Jupiter

411
00:17:18.270 --> 00:17:19.350
in 2031.

412
00:17:19.670 --> 00:17:22.270
Avery: ESA says flying through the tail of Earth's

413
00:17:22.270 --> 00:17:24.870
magnetic field was a useful dress rehearsal.

414
00:17:25.030 --> 00:17:27.750
Juice has 35 flybys of Ganymede,

415
00:17:27.750 --> 00:17:30.030
Europa and Callisto ahead of it once it

416
00:17:30.030 --> 00:17:32.880
arrives. And fourth, the one you asked

417
00:17:32.880 --> 00:17:35.400
us to follow. The Link spacecraft sent to

418
00:17:35.400 --> 00:17:37.920
boost NASA's ageing Swift observatory re

419
00:17:37.920 --> 00:17:40.320
entered the atmosphere on 25 September

420
00:17:40.800 --> 00:17:42.720
after losing two of its three reaction

421
00:17:42.720 --> 00:17:44.920
wheels. It never had the fuel to attempt to

422
00:17:44.920 --> 00:17:47.800
capture, but its team did fly it to within 12

423
00:17:47.800 --> 00:17:50.440
to 15 kilometres of swift and practised

424
00:17:50.440 --> 00:17:53.360
moving its robot arms. NASA paid Catalyst $30

425
00:17:53.360 --> 00:17:55.720
million for the attempt and the spacecraft

426
00:17:55.720 --> 00:17:58.200
was built in under a year. Swift itself

427
00:17:58.200 --> 00:18:00.520
launched in 2004 and has spent more than two

428
00:18:00.520 --> 00:18:02.640
decades catching gamma ray bursts within

429
00:18:02.640 --> 00:18:04.800
seconds and swinging around to look at them.

430
00:18:05.120 --> 00:18:07.480
Work that made it a first responder for half

431
00:18:07.480 --> 00:18:08.800
the observatories on Earth.

432
00:18:09.120 --> 00:18:11.800
Anna: Swift is expected to follow it down in early

433
00:18:11.800 --> 00:18:14.440
November. Until then, it's back

434
00:18:14.440 --> 00:18:17.400
observing a gamma ray lookout working through

435
00:18:17.400 --> 00:18:19.960
its final weeks. Thank you to everyone who

436
00:18:19.960 --> 00:18:22.280
wrote in about this one. We'll mark Swift's

437
00:18:22.280 --> 00:18:23.120
end when it comes

438
00:18:23.800 --> 00:18:26.760
Avery: and one to watch. Japan's MMX mission,

439
00:18:26.840 --> 00:18:29.120
aiming to bring back the first samples ever

440
00:18:29.120 --> 00:18:31.840
from a moon of Mars, is set to launch on an

441
00:18:31.840 --> 00:18:34.240
H3 rocket from Tanegashima at

442
00:18:34.240 --> 00:18:37.016
06:41 on the morning of Tuesday 20th

443
00:18:37.144 --> 00:18:40.080
October Sydney time. That's the afternoon

444
00:18:40.080 --> 00:18:42.760
of Monday the 19th on the US east coast.

445
00:18:43.240 --> 00:18:46.080
Anna: Time for the sky and it's a good weekend for

446
00:18:46.080 --> 00:18:49.080
it. New moon arrives at 15:50

447
00:18:49.240 --> 00:18:51.970
Universal Time on Saturday. That's

448
00:18:51.970 --> 00:18:54.570
Saturday in the Americas and Europe, but

449
00:18:54.650 --> 00:18:56.970
2:50 on Sunday morning in Sydney.

450
00:18:57.450 --> 00:19:00.250
Either way, the next several evenings are

451
00:19:00.250 --> 00:19:03.250
Avery: properly dark, which makes it prime time

452
00:19:03.250 --> 00:19:06.210
for the zodiacal light. A faint cone

453
00:19:06.210 --> 00:19:08.690
of sunlight scattered off dust in the plane

454
00:19:08.690 --> 00:19:11.490
of the planets. The trick is the

455
00:19:11.490 --> 00:19:14.050
angle of that plane to your horizon. And

456
00:19:14.050 --> 00:19:16.050
right now the two hemispheres get

457
00:19:16.050 --> 00:19:18.620
Anna: opposite ends of the day. From Sydney,

458
00:19:18.780 --> 00:19:21.260
after astronomical Twilight ends around

459
00:19:21.260 --> 00:19:23.820
8:30 in the evening, the ecliptic

460
00:19:23.820 --> 00:19:26.500
stands about 75 degrees from the

461
00:19:26.500 --> 00:19:28.940
western horizon, nearly upright.

462
00:19:29.580 --> 00:19:32.540
Look west from a dark site for a tilted,

463
00:19:32.540 --> 00:19:35.260
tapering glow. A false dusk

464
00:19:36.140 --> 00:19:39.060
from Los Angeles. At the same stage it's

465
00:19:39.060 --> 00:19:41.420
about 38 degrees from New York,

466
00:19:41.500 --> 00:19:44.460
32 from London, only 23.

467
00:19:45.220 --> 00:19:47.660
So in the evening the north mostly misses

468
00:19:47.660 --> 00:19:47.940
out.

469
00:19:48.420 --> 00:19:51.300
Avery: But in the morning, it flips before

470
00:19:51.380 --> 00:19:54.340
astronomical dawn around half past five in

471
00:19:54.340 --> 00:19:56.740
Los Angeles and, uh, New York. The ecliptic

472
00:19:56.740 --> 00:19:59.340
stands about 79 degrees from the eastern

473
00:19:59.340 --> 00:20:02.260
horizon in LA, 73 in New York,

474
00:20:02.580 --> 00:20:05.500
62 in London. That's your false dawn.

475
00:20:05.500 --> 00:20:08.300
In the east from Sydney, it's only 33

476
00:20:08.300 --> 00:20:09.220
degrees in the morning.

477
00:20:09.780 --> 00:20:12.740
Anna: Same geometry as the steep evening Venus

478
00:20:12.740 --> 00:20:15.580
we described last month. It's all about how

479
00:20:15.580 --> 00:20:18.220
the plane of the planets meets your horizon.

480
00:20:19.100 --> 00:20:22.060
One practical note, for Australians, daylight

481
00:20:22.060 --> 00:20:24.620
saving began last Sunday in New South Wales,

482
00:20:24.940 --> 00:20:26.380
Victoria, the act,

483
00:20:27.020 --> 00:20:29.180
Tasmania and South Australia.

484
00:20:29.740 --> 00:20:32.540
So all our Sydney times are now daylight

485
00:20:32.540 --> 00:20:35.420
time. Southern listeners also get a rare

486
00:20:35.420 --> 00:20:38.180
twilight treat. Mercury is near its

487
00:20:38.180 --> 00:20:40.900
greatest distance from the sun, magnitude 0,

488
00:20:41.060 --> 00:20:43.620
sitting 24 degrees up at sunset from

489
00:20:43.620 --> 00:20:46.380
Sydney. Actually higher than Venus, which is

490
00:20:46.380 --> 00:20:48.540
22 degrees up at magnitude

491
00:20:48.540 --> 00:20:51.420
-4.3 and sets almost two hours

492
00:20:51.420 --> 00:20:53.620
after the sun from the north.

493
00:20:53.860 --> 00:20:56.500
Avery: Sorry. At Sunset,

494
00:20:56.500 --> 00:20:59.460
Venus is 4 degrees up in Los Angeles, under

495
00:20:59.460 --> 00:21:02.140
2 in New York and already below the

496
00:21:02.140 --> 00:21:05.100
horizon in London. And Venus is now

497
00:21:05.100 --> 00:21:08.020
sliding quickly towards the sun. So southern

498
00:21:08.020 --> 00:21:09.780
viewers catch it this week.

499
00:21:10.340 --> 00:21:12.540
Anna: And because both planets are close to the

500
00:21:12.540 --> 00:21:15.300
Sun, a safety line we never skip.

501
00:21:15.700 --> 00:21:17.620
Never look at the sun with your eyes,

502
00:21:17.700 --> 00:21:20.580
binoculars or a telescope. And never

503
00:21:20.580 --> 00:21:23.300
sweep binoculars across the western sky until

504
00:21:23.300 --> 00:21:26.260
the sun is fully down. Any solar viewer

505
00:21:26.260 --> 00:21:27.620
must meet the ISO

506
00:21:27.620 --> 00:21:30.260
123122 standard

507
00:21:30.500 --> 00:21:32.700
and a filter goes over the front of any

508
00:21:32.700 --> 00:21:34.930
optics, never at the eyepiece.

509
00:21:35.490 --> 00:21:38.130
Avery: Northern listeners, your reward is before

510
00:21:38.130 --> 00:21:40.970
dawn. Mars is passing through the Beehive

511
00:21:40.970 --> 00:21:43.770
Star cluster, closest little more than a

512
00:21:43.770 --> 00:21:46.650
tenth of a degree on the 11th Universal

513
00:21:46.650 --> 00:21:49.090
Time and within half a degree either side.

514
00:21:49.490 --> 00:21:52.210
Binoculars make it lovely. At

515
00:21:52.210 --> 00:21:55.210
nautical dawn on Monday, Mars is about 57

516
00:21:55.210 --> 00:21:57.810
degrees up from LA 55 from New York,

517
00:21:58.050 --> 00:22:00.800
49 from London against 23 from

518
00:22:00.800 --> 00:22:03.480
Sydney. Jupiter is nearby,

519
00:22:03.640 --> 00:22:06.560
15 degrees away and closing. The two will

520
00:22:06.560 --> 00:22:09.240
be just over a degree apart in mid November.

521
00:22:09.640 --> 00:22:11.960
Anna: Southern predawn watchers can see the pair

522
00:22:11.960 --> 00:22:14.960
too, just lower. Mars about 23

523
00:22:14.960 --> 00:22:17.640
degrees up at nautical dawn from Sydney and

524
00:22:17.640 --> 00:22:20.640
Jupiter 17. Mars is at magnitude

525
00:22:20.640 --> 00:22:23.560
plus 1.1 and Jupiter at minus

526
00:22:23.560 --> 00:22:26.480
1.8, so the colour contrast is easy

527
00:22:26.480 --> 00:22:27.720
even in a bright sky.

528
00:22:28.230 --> 00:22:30.590
Avery: Saturn, just past opposition, is

529
00:22:30.590 --> 00:22:33.430
magnitude 0.35 and, um, well

530
00:22:33.430 --> 00:22:36.310
placed for everyone. Highest around half past

531
00:22:36.310 --> 00:22:39.230
midnight local time. 54 degrees up from

532
00:22:39.230 --> 00:22:42.110
Sydney, 58 from LA 51 from

533
00:22:42.110 --> 00:22:44.910
New York, 40 from London. The

534
00:22:44.910 --> 00:22:47.830
rings are tilted only about 7 degrees, so

535
00:22:47.830 --> 00:22:49.190
they look unusually, um, thin.

536
00:22:49.590 --> 00:22:52.310
Anna: While you're with Saturn, remember NGC

537
00:22:52.310 --> 00:22:54.940
1068. From the lead, the neutrino

538
00:22:54.940 --> 00:22:57.740
galaxy is in Cetus II. A, uh, small telescope

539
00:22:57.740 --> 00:23:00.740
target near the star Delta Ceti. Asteroid

540
00:23:00.740 --> 00:23:03.180
Vesta also reaches opposition on Tuesday the

541
00:23:03.180 --> 00:23:06.100
13th in Cetus within reach of binoculars.

542
00:23:06.340 --> 00:23:08.940
And the Orionid meteor shower peaks on the

543
00:23:08.940 --> 00:23:11.940
night of the 21st into the 22nd. There will

544
00:23:11.940 --> 00:23:14.540
be a fat waxing moon early in the night, so

545
00:23:14.540 --> 00:23:16.620
the hours before dawn are best from both

546
00:23:16.620 --> 00:23:19.020
hemispheres. The Orionids are dust from

547
00:23:19.020 --> 00:23:21.500
Hallie's comet, so it's a chance to catch a

548
00:23:21.500 --> 00:23:24.340
little of Hallie ahead of its return in 2061.

549
00:23:25.050 --> 00:23:27.340
Avery: Um, and that's the show. Thank you for your

550
00:23:27.340 --> 00:23:29.660
patience over the past couple of weeks. It's

551
00:23:29.660 --> 00:23:32.220
good to be back. A Nobel for a

552
00:23:32.220 --> 00:23:34.940
telescope made of ice, the most distant

553
00:23:34.940 --> 00:23:37.900
fast radio burst, a planet that may have been

554
00:23:37.900 --> 00:23:40.779
built from a dying star, and a lot of

555
00:23:40.779 --> 00:23:43.140
catching up. Get WOL soon, Huw.

556
00:23:43.540 --> 00:23:46.100
And as ever, the credit for this show belongs

557
00:23:46.100 --> 00:23:48.540
to the whole team behind it. If you've got a

558
00:23:48.540 --> 00:23:50.340
question you'd like us to chase the way you

559
00:23:50.340 --> 00:23:52.580
did with Link and Swift, use the contact

560
00:23:52.580 --> 00:23:55.480
form@astronomydaily.IO you'll

561
00:23:55.480 --> 00:23:58.440
find us on socials. Astrodaily pod and

562
00:23:58.440 --> 00:24:00.000
the show notes have every source.

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00:24:00.240 --> 00:24:01.200
Anna: I'm Anna.

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00:24:01.520 --> 00:24:03.840
Avery: And I'm Avery. Clear Skies.