Astronomy Daily S05E216 — A New World in the Crowd (Thursday 29 October 2026). Hosts Anna and Avery. Lead: the Vera C. Rubin Observatory has found its first dwarf-planet candidate. 2026 ED138 lies beyond Pluto, about 46 au from the Sun. Matthew Holman (CfA) found it on 13 October with a search code built with Kevin Napier, and it was announced on 27 October at the DPS meeting in Spokane (MPEC 2026-U85). Rubin caught it 30 times on 20 nights between March and July, and Dark Energy Camera precoveries extend the orbit back to 2016. Only nine known trans-Neptunian objects are intrinsically brighter. Its size is estimated at 600–1,500 km, depending on reflectivity, so it remains a candidate until infrared or occultation measurements pin it down. It hid near the plane of the Milky Way, about 43° south of the celestial equator. Also: JWST's 37-hour phase curve shows the lava world TOI-561 b reflecting about three-quarters of its starlight, possibly through silicate clouds, with University of Sydney co-authors. ESA's Hera resolves Didymos and Dimorphos separately for the first time, with detailed Dimorphos images due 25 November. NASA's Swift is in its final weeks before re-entry, and UVEX passes a key review. Skywatch for Sydney, Los Angeles, New York and London: Mars and Jupiter closing in the pre-dawn sky (1.2° on 16 November), Saturn in the evening, Mercury's last call from the south, the waning Moon through Taurus to Gemini, and the US clock change on 1 November.
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00:00:00 --> 00:00:03 Anna: Somewhere past Pluto, in one of the
00:00:03 --> 00:00:06 most crowded patches of the sky, there's
00:00:06 --> 00:00:09 an icy world that may be close
00:00:09 --> 00:00:11 to a thousand kilometres across.
00:00:12 --> 00:00:14 It has been sitting in plain sight for at
00:00:14 --> 00:00:17 least a decade and nobody
00:00:17 --> 00:00:20 Avery: saw it because it was lost among millions of
00:00:20 --> 00:00:22 stars. Then the Vera Rubin
00:00:22 --> 00:00:25 Observatory looked at the same patch of sky
00:00:25 --> 00:00:28 again and again and something
00:00:28 --> 00:00:28 moved.
00:00:29 --> 00:00:31 Anna: Welcome to Astronomy AstroDailyPod.
00:00:31 --> 00:00:33 I'm Anna and I'm um.
00:00:33 --> 00:00:35 Avery: Avery. Today Rubin's first
00:00:35 --> 00:00:38 dwarf planet candidate lava world that
00:00:38 --> 00:00:41 reflects 3/4 of the starlight hitting it
00:00:41 --> 00:00:44 and Hera finally seeing its two asteroids as
00:00:44 --> 00:00:47 two. Plus Swift's final weeks and a
00:00:47 --> 00:00:50 uh, busy pre dawn sky for both hemispheres.
00:00:50 --> 00:00:52 Anna: It's Thursday 29th October.
00:00:53 --> 00:00:54 Let's get into it.
00:00:54 --> 00:00:57 Avery: On Tuesday US time at the annual meeting
00:00:57 --> 00:01:00 of the American Astronomical Society's
00:01:00 --> 00:01:02 Division for Planetary Sciences in Spokane,
00:01:02 --> 00:01:04 Washington, the Rubin Observatory team
00:01:04 --> 00:01:07 announced its first Dwarf Planet candidate.
00:01:07 --> 00:01:10 Its provisional name is 2026
00:01:10 --> 00:01:13 ED138 and the minor Planet Centre published
00:01:13 --> 00:01:14 the discovery the same day.
00:01:14 --> 00:01:17 Anna: Let's start with what it actually is.
00:01:17 --> 00:01:20 Ed138 is a uh, Trans Neptunian
00:01:20 --> 00:01:23 object, so it orbits beyond Neptune.
00:01:23 --> 00:01:26 Right now it's about 46 astronomical units
00:01:26 --> 00:01:29 from the Sun. For comparison, Pluto's average
00:01:29 --> 00:01:31 distance is about 40.
00:01:32 --> 00:01:35 Avery: And it's bright, which is the striking part.
00:01:35 --> 00:01:38 Astronomers ranked these objects by absolute
00:01:38 --> 00:01:40 magnitude, which is how bright they'd look at
00:01:40 --> 00:01:43 a standard distance. ED138
00:01:43 --> 00:01:45 comes in at about 3.2.
00:01:46 --> 00:01:49 According to the Rubin Solar System Tim, only
00:01:49 --> 00:01:51 nine known trans Neptunian objects are
00:01:51 --> 00:01:53 intrinsically brighter.
00:01:53 --> 00:01:56 Anna: That puts it in very select company. The
00:01:56 --> 00:01:59 objects above it on that list include Pluto,
00:01:59 --> 00:02:02 Eris, Haumea and Makemake,
00:02:02 --> 00:02:05 which are four of the five dwarf planets the
00:02:05 --> 00:02:07 International Astronomical Union officially
00:02:07 --> 00:02:10 recognises. The fifth is Ceres
00:02:10 --> 00:02:11 in the asteroid belt.
00:02:11 --> 00:02:14 Avery: It's worth a quick reminder of what dwarf
00:02:14 --> 00:02:17 planet means because the definition does the
00:02:17 --> 00:02:19 work in this story. Under the IAU's
00:02:20 --> 00:02:22 2006 rules, a planet orbits the sun
00:02:23 --> 00:02:25 has enough gravity to pull itself into a
00:02:25 --> 00:02:27 round shape and has cleared its orbital
00:02:27 --> 00:02:30 neighbourhood of other material. A dwarf
00:02:30 --> 00:02:31 planet meets the first two
00:02:31 --> 00:02:34 Anna: but not the third, which is why Pluto
00:02:34 --> 00:02:37 was moved into that category. It's round,
00:02:37 --> 00:02:40 but it shares its region with a crowd of
00:02:40 --> 00:02:42 Kuiper Belt objects. So for
00:02:42 --> 00:02:45 Ed138 the key question isn't
00:02:45 --> 00:02:48 distance or brightness, it's whether
00:02:48 --> 00:02:50 it's big enough to be round.
00:02:50 --> 00:02:53 Avery: The discovery story is about software
00:02:53 --> 00:02:56 as much as glass. On the evening of
00:02:56 --> 00:02:59 the 13th of October, Matthew Holman at
00:02:59 --> 00:03:01 the Centre for Astrophysics Harvard and
00:03:01 --> 00:03:04 Smithsonian, was running Rubin data from
00:03:04 --> 00:03:06 earlier this year through a search code he'd
00:03:06 --> 00:03:08 built with his colleague Kevin Napier.
00:03:09 --> 00:03:12 Anna: The code takes billions of detections of
00:03:12 --> 00:03:15 things that move and asks which of them are
00:03:15 --> 00:03:17 the same object seen on different nights.
00:03:17 --> 00:03:19 It's a, ah, connect the dots problem at
00:03:19 --> 00:03:20 enormous scale.
00:03:21 --> 00:03:23 Avery: And when ED138 popped out, its
00:03:23 --> 00:03:26 brightness and distance said it was unusually
00:03:26 --> 00:03:29 large. Holman said his first reaction
00:03:29 --> 00:03:32 was one of excited disbelief. So he started
00:03:32 --> 00:03:35 checking whether he or the code had made a
00:03:35 --> 00:03:36 mistake, which
00:03:36 --> 00:03:39 Anna: is exactly the right instinct. Mario
00:03:39 --> 00:03:41 Jurich at the University of Washington,
00:03:41 --> 00:03:44 Rubin's solar system lead scientist, went
00:03:44 --> 00:03:46 back through Rubin's catalogues and images.
00:03:47 --> 00:03:50 In total, Rubin had caught it 30 times
00:03:50 --> 00:03:53 on 20 nights between the 4th of March and
00:03:53 --> 00:03:54 the 11th of July.
00:03:55 --> 00:03:57 Avery: Then, um, they went further back. Archival
00:03:57 --> 00:04:00 images from the Dark Energy Camera turned up
00:04:00 --> 00:04:02 through the Asteroid Institute's Precovery
00:04:02 --> 00:04:05 Service, founded on 14 nights between
00:04:05 --> 00:04:08 2016 and 2020. So the
00:04:08 --> 00:04:10 team now has more than 10 years of the orbit.
00:04:11 --> 00:04:13 Anna: So why was something this bright missed for
00:04:13 --> 00:04:14 so long?
00:04:15 --> 00:04:17 Avery: Location ED138
00:04:17 --> 00:04:20 sits about 43 degrees south of the
00:04:20 --> 00:04:23 celestial equator and close to the plane of
00:04:23 --> 00:04:24 the Milky Way.
00:04:24 --> 00:04:27 That's a field packed with millions of
00:04:27 --> 00:04:30 stars. And a faint dot that moves
00:04:30 --> 00:04:32 a little each night is very easy to lose
00:04:32 --> 00:04:33 against them.
00:04:33 --> 00:04:36 Anna: And Rubin is built for exactly that problem.
00:04:37 --> 00:04:40 It pairs an 8.4 metre telescope with
00:04:40 --> 00:04:42 the largest digital camera ever made for
00:04:42 --> 00:04:45 astronomy, about 3.2 gigapixels.
00:04:45 --> 00:04:48 And it images the whole southern sky every
00:04:48 --> 00:04:51 few nights. So it doesn't just see a
00:04:51 --> 00:04:54 faint dot, it sees the same faint
00:04:54 --> 00:04:56 dot in a slightly different place night after
00:04:56 --> 00:04:59 night. And the software stitches those
00:04:59 --> 00:05:00 positions into an orbit.
00:05:01 --> 00:05:03 Avery: It's another version of something we keep
00:05:03 --> 00:05:06 coming back to on this show. A catalogue, uh,
00:05:06 --> 00:05:08 tells you what a survey could detect. Not
00:05:08 --> 00:05:09 everything that's out there.
00:05:10 --> 00:05:13 Earlier surveys didn't miss ED138 because it
00:05:13 --> 00:05:15 wasn't there. They missed it because of where
00:05:15 --> 00:05:16 it was.
00:05:16 --> 00:05:19 Anna: The orbit is interesting in its own right.
00:05:19 --> 00:05:21 Its average distance from the sun is about
00:05:21 --> 00:05:24 43 astronomical units. It's
00:05:24 --> 00:05:27 moderately eccentric and it's tilted about
00:05:27 --> 00:05:30 24 degrees to the plane of the planets.
00:05:31 --> 00:05:33 That makes it what's called a hot classical
00:05:33 --> 00:05:36 object, which suggests Neptune pushed it
00:05:36 --> 00:05:37 around at some point in the past.
00:05:38 --> 00:05:40 Avery: And, uh, there's a detail from the team that
00:05:40 --> 00:05:43 I like. It sits near a 12,7
00:05:43 --> 00:05:45 resonance with Neptune, the same
00:05:45 --> 00:05:48 neighbourhood as Haumea. But only about
00:05:48 --> 00:05:50 half of the possible orbit solutions actually
00:05:50 --> 00:05:53 stay locked in that resonance. So whether
00:05:53 --> 00:05:55 it's a true Resonant object isn't settled
00:05:55 --> 00:05:56 yet.
00:05:56 --> 00:05:59 Anna: Its colour also rules out one tempting.
00:06:00 --> 00:06:02 It's redder than the members of the Haumea,
00:06:02 --> 00:06:04 uh, Collision family, so it doesn't look like
00:06:04 --> 00:06:05 a fragment of that system.
00:06:06 --> 00:06:08 Avery: Now, the honest part, and, um, it matters.
00:06:09 --> 00:06:12 Ed138 is a candidate, not
00:06:12 --> 00:06:13 a confirmed dwarf planet.
00:06:14 --> 00:06:17 Anna: The size estimate is the reason all we
00:06:17 --> 00:06:19 really measure is how much sunlight it
00:06:19 --> 00:06:21 reflects back to us. A small, very
00:06:21 --> 00:06:24 shiny object and a big, very dark one can
00:06:24 --> 00:06:27 look equally bright. Holman made the
00:06:27 --> 00:06:30 same. The team can see how much light
00:06:30 --> 00:06:32 arrives, not how big the thing is.
00:06:33 --> 00:06:36 Avery: So the range is wide. The team's
00:06:36 --> 00:06:39 estimate runs from about 600 to
00:06:39 --> 00:06:42 1500 kilometres across, depending on
00:06:42 --> 00:06:43 the albedo you assume.
00:06:44 --> 00:06:46 At a middle of the road reflectivity, it
00:06:46 --> 00:06:48 comes out a little under 1000 kilometres.
00:06:49 --> 00:06:51 Anna: Even the low end is in the range where icy
00:06:51 --> 00:06:54 bodies are expected to pull themselves round
00:06:54 --> 00:06:57 under their own gravity, which is the key
00:06:57 --> 00:06:59 test for a dwarf planet. But expected
00:07:00 --> 00:07:02 isn't measured. To pin the size down,
00:07:02 --> 00:07:05 you need either infrared observations, which
00:07:05 --> 00:07:07 tell you how warm it is and therefore how
00:07:07 --> 00:07:10 dark, or a, uh, stellar occultation,
00:07:10 --> 00:07:12 where it passes in front of a star and its
00:07:12 --> 00:07:15 shadow sweeps across observers on the ground.
00:07:15 --> 00:07:18 Avery: Until one of those happens, the right word is
00:07:18 --> 00:07:21 candidate, and the official dwarf planet list
00:07:21 --> 00:07:24 is an IAU decision, not a press release.
00:07:25 --> 00:07:27 Anna: This one has a strong southern hemisphere
00:07:27 --> 00:07:30 angle. Rubin sits on Cerro Pechone in
00:07:30 --> 00:07:32 Chile. The precovery images came from the
00:07:32 --> 00:07:35 Dark Energy camera on the Blanco 4 metre
00:07:35 --> 00:07:37 telescope at nearby Cerro Tololo, the same
00:07:37 --> 00:07:40 camera whose supernova data fed the dark
00:07:40 --> 00:07:43 energy story we covered back in episode 193.
00:07:43 --> 00:07:46 Avery: And the object itself is a southern one
00:07:46 --> 00:07:49 at 43 degrees south. I ran the
00:07:49 --> 00:07:51 numbers from Sydney.
00:07:51 --> 00:07:53 Its part of the sky climbs to about 81
00:07:53 --> 00:07:56 degrees, close to overhead. From
00:07:56 --> 00:07:59 Los Angeles it never gets above about 13
00:07:59 --> 00:08:02 degrees, from New York about 6.
00:08:02 --> 00:08:05 And from London it never rises at all.
00:08:05 --> 00:08:08 Anna: One clarification for listeners. You won't
00:08:08 --> 00:08:10 see this in a backyard telescope.
00:08:10 --> 00:08:13 It's around magnitude 19, which is
00:08:13 --> 00:08:15 professional telescope territory. But the
00:08:15 --> 00:08:18 geometry matters for science. If its size
00:08:18 --> 00:08:21 ends up coming from an occultation, the
00:08:21 --> 00:08:23 observers best place to catch that shadow are
00:08:23 --> 00:08:24 likely to be in the south.
00:08:25 --> 00:08:27 Avery: And Holman's own framing of what comes next
00:08:27 --> 00:08:30 is the bigger point. Rubin will image the
00:08:30 --> 00:08:33 whole southern sky again and again for 10
00:08:33 --> 00:08:33 years.
00:08:34 --> 00:08:36 So anything else hiding in places earlier
00:08:37 --> 00:08:39 surveys skipped is now within reach
00:08:39 --> 00:08:40 for context.
00:08:41 --> 00:08:43 Anna: The formal legacy survey of space and time
00:08:43 --> 00:08:46 only began in June. Back in April,
00:08:46 --> 00:08:49 before it started, the team submitted more
00:08:49 --> 00:08:51 than 11 new asteroids to the Minor
00:08:51 --> 00:08:54 Planet Centre, including roughly
00:08:54 --> 00:08:56 380 new trans Neptunian
00:08:56 --> 00:08:57 objects.
00:08:57 --> 00:09:00 Avery: This is our third Rubin story in recent
00:09:00 --> 00:09:03 weeks. After the hidden globular cluster in
00:09:03 --> 00:09:05 episode 195 and the Seagull
00:09:05 --> 00:09:08 Nebula image in episode 212, it's
00:09:08 --> 00:09:11 the first new world in our own solar system.
00:09:12 --> 00:09:13 It almost certainly won't be the last.
00:09:14 --> 00:09:17 Anna: Next, A, uh, planet that probably shouldn't
00:09:17 --> 00:09:19 have an atmosphere at all. Tigoi
00:09:19 --> 00:09:22 561b is a rocky world about
00:09:22 --> 00:09:24 1.4 times Earth's width,
00:09:25 --> 00:09:27 roughly 280 light years away.
00:09:28 --> 00:09:31 It orbits its star in under 11 hours,
00:09:31 --> 00:09:34 so close that its dayside is almost certainly
00:09:34 --> 00:09:35 an ocean of magma.
00:09:35 --> 00:09:37 Avery: Disclosure first.
00:09:37 --> 00:09:40 The evidence that this planet has a thick
00:09:40 --> 00:09:42 atmosphere was published last December.
00:09:42 --> 00:09:44 What's new this month in the Astronomical
00:09:44 --> 00:09:47 Journal is what that atmosphere does.
00:09:47 --> 00:09:50 The preprint went up in late August, so it's
00:09:50 --> 00:09:52 about two months older than the Journal
00:09:52 --> 00:09:53 version.
00:09:53 --> 00:09:56 Anna: The team led by Samuel Boucher and Lisa
00:09:56 --> 00:09:59 Dang watched the system with the James
00:09:59 --> 00:10:01 Webb space telescope for 37 hours
00:10:01 --> 00:10:04 straight, hovering nearly four full orbits.
00:10:05 --> 00:10:06 That gives you a phase curve.
00:10:07 --> 00:10:10 How, uh, the planet's glow changes as its hot
00:10:10 --> 00:10:12 dayside and cooler night side turn
00:10:12 --> 00:10:13 toward us.
00:10:14 --> 00:10:16 Avery: And the dayside is far too cool.
00:10:17 --> 00:10:20 A bare dark rock that close to its star
00:10:20 --> 00:10:22 should reach about 3200
00:10:22 --> 00:10:25 kelvin. TOI561B's dayside
00:10:25 --> 00:10:26 comes in at about
00:10:26 --> 00:10:29 2050and the night side
00:10:29 --> 00:10:32 is about 1100. So
00:10:33 --> 00:10:35 some heat is getting carried around the
00:10:35 --> 00:10:35 planet.
00:10:35 --> 00:10:38 Anna: Their best explanation is that the planet
00:10:38 --> 00:10:41 reflects roughly 3/4 of the starlight that
00:10:41 --> 00:10:43 hits it. That's comparable to Venus.
00:10:44 --> 00:10:46 And the culprit could be clouds of silicate
00:10:46 --> 00:10:49 minerals, quartz like silicon dioxide and
00:10:49 --> 00:10:52 magnesium silicate forming near the edge of
00:10:52 --> 00:10:54 the dayside and acting like sunscreen.
00:10:55 --> 00:10:58 Avery: Here is the Australian thread. One of
00:10:58 --> 00:11:00 the hardest parts of this measurement is that
00:11:00 --> 00:11:01 the star itself flickers.
00:11:02 --> 00:11:04 Its surface boils with convection cells
00:11:05 --> 00:11:07 called granulation, which make tiny
00:11:07 --> 00:11:09 brightness changes that can mimic a planetary
00:11:09 --> 00:11:12 signal. Co authors at the Sydney Institute
00:11:12 --> 00:11:14 for Astronomy at the University of Sydney
00:11:14 --> 00:11:17 worked on separating that stellar flicker
00:11:17 --> 00:11:20 from the planet. That's One reason the 37
00:11:20 --> 00:11:21 hour baseline is so valuable.
00:11:22 --> 00:11:25 Anna: Caveats because there are real ones.
00:11:25 --> 00:11:27 The atmosphere's composition is still
00:11:27 --> 00:11:28 unknown.
00:11:28 --> 00:11:31 Webb's two detectors don't fully agree with
00:11:31 --> 00:11:33 each other and the authors say they can't
00:11:33 --> 00:11:35 rule out instrument effects for part of that.
00:11:36 --> 00:11:38 What they'd like next is a mid infrared
00:11:38 --> 00:11:41 phase curve with Webb's MIRI instrument.
00:11:41 --> 00:11:44 This matters beyond one planet.
00:11:44 --> 00:11:47 Most of Webb's rocky planet. Results so far
00:11:47 --> 00:11:49 have pointed towards bare rock.
00:11:49 --> 00:11:51 But most of those planets orbit small red
00:11:51 --> 00:11:53 dwarf stars. POI
00:11:53 --> 00:11:56 561 orbits a star a bit smaller and
00:11:56 --> 00:11:59 cooler than the sun. So it may be telling us
00:11:59 --> 00:12:01 those results don't apply everywhere.
00:12:02 --> 00:12:04 Avery: And the bigger puzzle is still open.
00:12:05 --> 00:12:08 A small planet this heavily irradiated around
00:12:08 --> 00:12:10 a star more than 10 billion years old,
00:12:11 --> 00:12:12 should have lost its air long ago.
00:12:13 --> 00:12:16 The authors list several possible ways out,
00:12:16 --> 00:12:18 including the planet being born with a, uh,
00:12:19 --> 00:12:21 huge store of volatiles or gases
00:12:21 --> 00:12:24 locked in its interior and slowly released.
00:12:24 --> 00:12:27 Anna: Over and Dong's next question is
00:12:27 --> 00:12:30 whether this atmosphere looks more like Venus
00:12:30 --> 00:12:33 or like an extreme version of Jupiter's
00:12:33 --> 00:12:36 volcanic moon IO now an update on
00:12:36 --> 00:12:36 a
00:12:36 --> 00:12:39 Avery: mission we've been following closely. ESA's
00:12:39 --> 00:12:41 Hera spacecraft has seen its target as two
00:12:41 --> 00:12:43 asteroids for the first time.
00:12:43 --> 00:12:44 Anna: Quick recap.
00:12:45 --> 00:12:47 In September 2022, NASA's
00:12:47 --> 00:12:50 DART spacecraft deliberately crashed into a
00:12:50 --> 00:12:53 small asteroid called Dimorphos, which orbits
00:12:53 --> 00:12:56 a larger one called Didymos. The impact
00:12:56 --> 00:12:59 shortened Dimorphos orbit by about 33
00:12:59 --> 00:13:02 minutes. It was the first time humans had
00:13:02 --> 00:13:04 measurably changed the path of an object in
00:13:04 --> 00:13:05 the solar system.
00:13:05 --> 00:13:08 Avery: HERA is the follow up. The crime scene
00:13:08 --> 00:13:11 investigator ESA confirmed this week
00:13:11 --> 00:13:13 that its two braking burns, the ones we
00:13:13 --> 00:13:15 tracked on the show, both worked.
00:13:15 --> 00:13:18 They slowed the spacecraft to just 20 metres
00:13:18 --> 00:13:20 per second relative to the asteroids.
00:13:21 --> 00:13:23 Anna: And the new Picture is from 18
00:13:23 --> 00:13:26 October, taken with HERA's asteroid
00:13:26 --> 00:13:29 framing camera from 1280
00:13:29 --> 00:13:31 kilometres away. Until then, the
00:13:31 --> 00:13:34 system showed up as a single dot. Now
00:13:34 --> 00:13:36 Dimorphos appear separately.
00:13:37 --> 00:13:39 Avery: It's barely one pixel, which
00:13:39 --> 00:13:41 ESA's Michael Keppers acknowledged.
00:13:42 --> 00:13:44 But it's clearly separated from its parent.
00:13:45 --> 00:13:47 Dimorphos is about 150 metres across,
00:13:48 --> 00:13:50 roughly the size of the Great Pyramid of
00:13:50 --> 00:13:52 Giza. And it circles the
00:13:52 --> 00:13:54 780 metre didymos about
00:13:54 --> 00:13:56 1.15 kilometres away.
00:13:57 --> 00:13:59 Anna: And it circles slowly at about 18
00:13:59 --> 00:14:02 centimetres per second, slower than a
00:14:02 --> 00:14:05 gentle stroll. The whole system is currently
00:14:05 --> 00:14:08 about 197 million kilometres
00:14:08 --> 00:14:09 from Earth.
00:14:09 --> 00:14:12 When DART hit at 6.1 kilometres
00:14:12 --> 00:14:15 per second, it threw a plume of
00:14:15 --> 00:14:18 debris across 10 kilometres of space.
00:14:19 --> 00:14:21 The questions HERA is there to answer are
00:14:21 --> 00:14:23 important. Did Dart leave a crater
00:14:23 --> 00:14:26 or did it reshape the whole asteroid?
00:14:26 --> 00:14:29 What's Dimorphos mass? And why was the
00:14:29 --> 00:14:31 deflection so much bigger than the
00:14:31 --> 00:14:32 simulations predicted?
00:14:33 --> 00:14:35 You need those answers to turn one dramatic
00:14:35 --> 00:14:38 experiment into a planetary defence technique
00:14:38 --> 00:14:39 you can rely on.
00:14:39 --> 00:14:42 Avery: And there's a date to note. Mission manager
00:14:42 --> 00:14:45 Ian Carnelli says the first detailed images
00:14:45 --> 00:14:48 of Dimorphos will be released on 25th
00:14:48 --> 00:14:51 November. After that come two small
00:14:51 --> 00:14:53 cubesats for even closer work and um,
00:14:53 --> 00:14:55 eventually a landing.
00:14:55 --> 00:14:57 Anna: One more planetary defence.
00:14:57 --> 00:15:00 Note this. NASA's NEO
00:15:00 --> 00:15:02 Surveyor, the infrared telescope designed to
00:15:02 --> 00:15:05 find hazardous asteroids before they find us,
00:15:05 --> 00:15:07 has had its solar arrays integrated onto its
00:15:07 --> 00:15:10 sunshade gira ah checks how well we can
00:15:10 --> 00:15:13 deflect one NEO Surveyor is how we'd find
00:15:13 --> 00:15:16 it in time. And next, two
00:15:16 --> 00:15:18 quick ones. First, Swift.
00:15:18 --> 00:15:21 NASA formally ended the observatory's mission
00:15:21 --> 00:15:23 last week on 20 October.
00:15:23 --> 00:15:25 It had dropped to about 275
00:15:25 --> 00:15:28 kilometres and the team sent the command that
00:15:28 --> 00:15:30 ended operations ahead of reentry.
00:15:30 --> 00:15:33 Avery: NASA says reentry is expected within the next
00:15:33 --> 00:15:36 few weeks and it will be uncontrolled.
00:15:36 --> 00:15:39 Some reporting now says as soon as next week.
00:15:39 --> 00:15:42 But NASA hasn't published a date so we won't
00:15:42 --> 00:15:45 give you one. When it happens, you'll hear it
00:15:45 --> 00:15:45 here.
00:15:46 --> 00:15:48 Anna: This one closes the thread. Listeners started
00:15:48 --> 00:15:50 back in September when you wrote in asking
00:15:50 --> 00:15:53 what the link rescue mission was doing. Thank
00:15:53 --> 00:15:54 you for following it with us.
00:15:55 --> 00:15:57 Avery: And second, some good news for a future
00:15:57 --> 00:16:00 telescope. NASA's Ultraviolet
00:16:00 --> 00:16:03 Explorer UVex has passed its key
00:16:03 --> 00:16:04 decision Point C review.
00:16:05 --> 00:16:07 That means NASA has committed to a launch by
00:16:07 --> 00:16:10 January 2031 and a total life
00:16:10 --> 00:16:13 cycle cost of $590 million.
00:16:13 --> 00:16:15 It will survey the whole sky in ultraviolet
00:16:15 --> 00:16:18 light, which is where hot young stars and
00:16:18 --> 00:16:21 fast changing cosmic events show up best.
00:16:21 --> 00:16:24 Anna: Next, what have you got for us in Skywatch?
00:16:25 --> 00:16:27 Avery: Time to look up. The moon is
00:16:27 --> 00:16:30 waning about 89% lit on
00:16:30 --> 00:16:33 Thursday night, so the evening is bright for
00:16:33 --> 00:16:34 a few more days.
00:16:35 --> 00:16:38 It reaches Last quarter at 28 minutes past 8
00:16:38 --> 00:16:41 UTC on Sunday 1st November.
00:16:41 --> 00:16:43 That's half past seven on Monday morning in
00:16:43 --> 00:16:44 Sydney.
00:16:44 --> 00:16:47 Anna: Northern listeners, a uh, reminder clocks in
00:16:47 --> 00:16:50 the US go back one hour this Sunday the
00:16:50 --> 00:16:53 1st of November. The UK already changed
00:16:53 --> 00:16:56 last weekend. Any US times I give after
00:16:56 --> 00:16:58 Sunday are on standard time.
00:16:58 --> 00:17:00 Avery: The best show is before sunrise.
00:17:01 --> 00:17:04 Mars and Jupiter are heading towards each
00:17:04 --> 00:17:06 other on Thursday morning. They're about 7
00:17:06 --> 00:17:09 degrees apart. They close to about
00:17:09 --> 00:17:12 4 degrees by the 5th of November and
00:17:12 --> 00:17:15 they're closest at about 1.2
00:17:15 --> 00:17:17 degrees on the 16th.
00:17:17 --> 00:17:20 Anna: This one favours the north at
00:17:20 --> 00:17:21 nautical dawn on Friday.
00:17:22 --> 00:17:24 Mars is about 64 degrees up from Los
00:17:24 --> 00:17:27 Angeles and Jupiter about 58.
00:17:28 --> 00:17:31 New York is close behind at 61 and 55
00:17:31 --> 00:17:34 and London is still well placed at
00:17:34 --> 00:17:35 53 and 48.
00:17:36 --> 00:17:39 Avery: From Sydney they're lower but still easy
00:17:39 --> 00:17:42 about 26 and 24 degrees above the
00:17:42 --> 00:17:45 eastern horizon at dawn. Jupiter is the
00:17:45 --> 00:17:47 brilliant one, about magnitude minus two.
00:17:48 --> 00:17:51 Mars is the fainter orange point, and
00:17:51 --> 00:17:54 Regulus, the heart of leo, sits about 13
00:17:54 --> 00:17:55 degrees from Mars.
00:17:55 --> 00:17:58 Anna: Watching them close is a good project for the
00:17:58 --> 00:18:00 next three weeks. Check the gap every few
00:18:00 --> 00:18:03 mornings and you'll see it shrink, which is a
00:18:03 --> 00:18:05 simple way to see that the planets really do
00:18:05 --> 00:18:07 move against the stars.
00:18:07 --> 00:18:10 Binoculars on the 16th will show both in the
00:18:10 --> 00:18:13 same field in the evening. Saturn is the
00:18:13 --> 00:18:16 steady yellowish point that doesn't twinkle
00:18:16 --> 00:18:19 an hour after sunset on Thursday it's about
00:18:19 --> 00:18:22 38 degrees up from Sydney, 26 from
00:18:22 --> 00:18:25 Los Angeles, 22 from New York and
00:18:25 --> 00:18:26 14 from London.
00:18:27 --> 00:18:30 Avery: And this is Mercury's last call in the south.
00:18:30 --> 00:18:33 At sunset on Thursday, it's about 13
00:18:33 --> 00:18:35 degrees up from Sydney, low in the west,
00:18:36 --> 00:18:38 while from the northern Cities it's down at 5
00:18:38 --> 00:18:41 degrees or less. Look about 20 to 30
00:18:41 --> 00:18:44 minutes after sunset with a clear western
00:18:44 --> 00:18:46 horizon. It's slipping back towards the sun,
00:18:46 --> 00:18:48 so catch it in the next few nights.
00:18:49 --> 00:18:52 Anna: Venus is just past inferior conjunction
00:18:52 --> 00:18:55 between us and the sun, so it's lost
00:18:55 --> 00:18:57 in the glare for now. It'll come back into
00:18:57 --> 00:18:59 the morning sky over the next few weeks.
00:19:00 --> 00:19:02 Avery: Over the next few nights, the moon moves out
00:19:02 --> 00:19:05 of Taurus, past a bright orange star
00:19:05 --> 00:19:08 Aldebaran and Orion's shoulder star
00:19:08 --> 00:19:10 Betelgene, and on towards Gemini.
00:19:11 --> 00:19:14 By late On Saturday the 31st US time,
00:19:14 --> 00:19:16 it sits about 4 degrees from Pollux.
00:19:17 --> 00:19:19 Anna: It rises late from the south
00:19:20 --> 00:19:23 about a quarter past 11 on Thursday night in
00:19:23 --> 00:19:25 Sydney against early to mid
00:19:25 --> 00:19:28 evening from the northern cities. So
00:19:28 --> 00:19:30 Australian listeners will catch this better
00:19:30 --> 00:19:32 in the early morning and a ah
00:19:33 --> 00:19:34 Avery: callback to our lead.
00:19:34 --> 00:19:37 2026 ED138 sits
00:19:37 --> 00:19:40 about 43 degrees south of the celestial
00:19:40 --> 00:19:42 equator From Sydney, that part of the sky
00:19:42 --> 00:19:45 passes close to overhead at about 81 degrees.
00:19:46 --> 00:19:49 From Los Angeles it peaks at about 13,
00:19:49 --> 00:19:52 from New York 6, and from London
00:19:52 --> 00:19:55 it never rises. You'd need a professional
00:19:55 --> 00:19:58 telescope to see the object itself, but it's
00:19:58 --> 00:20:00 a good reminder of why a survey in Chile
00:20:00 --> 00:20:01 found it.
00:20:01 --> 00:20:04 Anna: And our standing reminder? Never look at the
00:20:04 --> 00:20:07 sun directly and never point binoculars or
00:20:07 --> 00:20:08 a telescope at it.
00:20:08 --> 00:20:11 If you're observing the sun, use only filters
00:20:11 --> 00:20:12 certified to the ISO
00:20:12 --> 00:20:15 123122 standard.
00:20:15 --> 00:20:17 Ordinary sunglasses are not safe.
00:20:18 --> 00:20:20 Avery: That's Astronomy AstroDailyPod for Thursday.
00:20:20 --> 00:20:23 Today, Rubin's first dwarf planet candidate
00:20:23 --> 00:20:25 hiding in the Milky Way's crowd, a lava
00:20:25 --> 00:20:28 planet that reflects 3/4 of its starlight and
00:20:28 --> 00:20:30 Hera finally seeing two asteroids.
00:20:31 --> 00:20:34 Anna: Show notes and links to every source are at
00:20:34 --> 00:20:37 astronomydaily IO or you can also
00:20:37 --> 00:20:38 join the newsletter and send us your
00:20:38 --> 00:20:40 questions through the contact form.
00:20:41 --> 00:20:43 Listener questions have shaped this show more
00:20:43 --> 00:20:45 than once, so keep them coming.
00:20:45 --> 00:20:48 Avery: You can find us astrodaily pod on
00:20:48 --> 00:20:50 social media and on, um, the bytes.com
00:20:50 --> 00:20:53 podcast network. This show is made by a small
00:20:53 --> 00:20:56 team who check every story back to its
00:20:56 --> 00:20:58 source. And we're grateful you spend some of
00:20:58 --> 00:20:58 your day with us.
00:20:59 --> 00:21:00 Anna: Keep looking up.
00:21:00 --> 00:21:01 I'm Anna.
00:21:01 --> 00:21:04 Avery: And I'm Avery. See you tomorrow. A
00:21:04 --> 00:21:07 star May day the
00:21:07 --> 00:21:08 stories be told
00:21:10 --> 00:21:10 Anna: Love.
00:21:15 --> 00:21:16 Avery: Story soul.