Anna and Avery open the Weekend Wrap with a genuine first: South Africa's MeerKAT has detected the 21-centimetre hydrogen signal from four to five billion light years away using radio data alone — no optical galaxy survey propping it up — proving out the technique the Square Kilometre Array will use to measure dark energy. Then the week in review: Roman's coronagraph wakes up, Starship Flight 14 gets a date, Mars turns out to be lopsided inside, BepiColombo lets go, LZ's one unexplained flash, and a centaur caught in the act of becoming a comet. Plus the sky for the week ahead, both hemispheres.
Links & sources · University of Manchester — Astronomers use MeerKAT to directly detect faint hydrogen signal from the distant Universe — https://www.manchester.ac.uk/about/news/astronomers-use-meerkat-to-directly-detect-faint-hydrogen-signal-from-the-distant-universe · The Astrophysical Journal Letters — Paul, Wolz, Santos, Chen et al. (paper DOI) — https://doi.org/10.3847/2041-8213/ae808f · American Astronomical Society — release listing — https://aas.org/node/730547 · Phys.org — MeerKAT directly detects faint hydrogen signal from the distant universe — https://phys.org/news/2026-09-meerkat-faint-hydrogen-distant-universe.html · Space.com — Scientists detect signals of hydrogen from billions of years ago — https://www.space.com/astronomy/galaxies/scientists-detect-signals-of-hydrogen-from-billions-of-years-ago-could-this-help-us-map-out-the-universe · Xinhua — MeerKAT in South Africa directly detects faint hydrogen signal from distant universe — https://english.news.cn/africa/20260905/3f6c7164a4404b0a9b79f879b1d31a59/c.html · SKA Observatory — the construction journey (SKA-Mid, Karoo; SKA-Low, Murchison) — https://www.skao.int/en/explore/construction-journey · NASA Science — Roman's planet imager has powered on (1 September 2026) — https://science.nasa.gov/blogs/roman/2026/09/01/nasa-romans-planet-imager-has-powered-on/ · NASA — NASA's dark universe-seeking Nancy Grace Roman Space Telescope launches — https://www.nasa.gov/news-release/nasas-dark-universe-seeking-nancy-grace-roman-space-telescope-launches/ · Next Spaceflight — Starship Flight 14 (NET 15 September 2026, Pad 2, Starbase) — https://nextspaceflight.com/launches/details/8346/ · Tesla Oracle — FCC filing points to Starship Flight 14 on 15 September; Booster 21 33-engine static fire — https://www.teslaoracle.com/2026/09/02/fcc-filing-reveals-starship-flight-14-launch-on-september-15-spacex-conducts-33-engine-static-fire-on-booster-21/ · Nature — Tidal tomography reveals a thermal anomaly beneath Mars's crustal dichotomy (27 August 2026) — https://www.nature.com/articles/s41586-026-10893-x · Phys.org — Thermal anomaly discovered below Mars' south pole — https://phys.org/news/2026-08-thermal-anomaly-mars-south-pole.html · ESA — Latest updates: BepiColombo's arrival at Mercury — https://www.esa.int/Science_Exploration/Space_Science/BepiColombo/Latest_updates_BepiColombo_s_arrival_at_Mercury · ESA — BepiColombo's Mercury arrival begins (full replay) — https://www.esa.int/ESA_Multimedia/Videos/2026/09/BepiColombo_s_Mercury_arrival_begins_-_full_replay · Brown University — LZ experiment sees surprising result in search for dark matter — https://www.brown.edu/news/2026-09-01/lz-dark-matter-results · The LZ Dark Matter Experiment — collaboration site — https://lz.lbl.gov/ · ARC Centre of Excellence for Dark Matter Particle Physics — Stawell Underground Physics Laboratory — https://www.centredarkmatter.org/supl · University of Central Florida — UCF researchers study a centaur transforming into a comet — https://www.ucf.edu/news/ucf-researchers-study-a-centaur-transforming-into-a-comet/ · Phys.org — Saturn encounter may have set distant centaur on path to becoming a comet — https://phys.org/news/2026-09-saturn-encounter-distant-centaur-path.html · Space.com — Scientists watch a comet being born 3 billion miles away — https://www.space.com/astronomy/comets/scientists-watch-a-comet-being-born-3-billion-miles-away · Star Walk — Astronomical events in September 2026 — https://starwalk.space/en/news/night-sky-tonight-september · EarthSky — Venus greatest brilliancy, 18 September 2026 (magnitude −4.8) — https://earthsky.org/astronomy-essentials/venus-brightest-greatest-brilliancy-greatest-illuminated-extent-2/ · EarthSky — Sun news: flares, CMEs and aurora updates — https://earthsky.org/sun/sun-news-activity-solar-flare-cme-aurora-updates/ · Space.com — Night sky September 2026: the best things to see this month — https://www.space.com/stargazing/what-to-see-night-sky-september-2026 Follow us: @AstroDailyPod · astronomydaily.io
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00:00:00 --> 00:00:03 Hey everyone, welcome back to Astronomy
00:00:03 --> 00:00:06 Daily. And it's Saturday, so you know
00:00:06 --> 00:00:08 what that means.
00:00:08 --> 00:00:11 >> The weekend rap. One brand new story
00:00:11 --> 00:00:14 properly developed and then we run back
00:00:14 --> 00:00:16 through the week's biggest news in case
00:00:16 --> 00:00:18 you missed any of it.
00:00:18 --> 00:00:21 >> It's Saturday, September 5th, 2026. I'm
00:00:21 --> 00:00:26 Anna and this is series 5, episode 186.
00:00:26 --> 00:00:29 >> And I'm Avery. Anna, today's fresh story
00:00:29 --> 00:00:31 is one I've been waiting years for
00:00:31 --> 00:00:33 somebody to pull off.
00:00:33 --> 00:00:35 >> A radio telescope in the Ku Desert has
00:00:35 --> 00:00:39 heard hydrogen, not from one galaxy,
00:00:39 --> 00:00:41 from billions of them at once, 4 to 5
00:00:41 --> 00:00:44 billion lightyear away. And it did it
00:00:44 --> 00:00:45 without any help from an optical
00:00:45 --> 00:00:48 telescope, which sounds modest until you
00:00:48 --> 00:00:50 understand that this particular signal
00:00:50 --> 00:00:53 is buried under a foreground about
00:00:53 --> 00:00:56 10 times brighter than it is. It's a
00:00:56 --> 00:00:57 technique people have been trying to
00:00:57 --> 00:01:00 make work for 15 years. This week it
00:01:00 --> 00:01:02 worked and it's a South African
00:01:02 --> 00:01:05 instrument that did it with a strong
00:01:05 --> 00:01:07 Australian sequel coming.
00:01:07 --> 00:01:10 >> Then the week that was Roman opened its
00:01:10 --> 00:01:14 planet camera's eyes. Starship flight 14
00:01:14 --> 00:01:16 finally has a date on it. Mars turned
00:01:16 --> 00:01:18 out to be hotter underneath than anyone
00:01:18 --> 00:01:22 expected. Bey Columbo let go of the ride
00:01:22 --> 00:01:25 that got it to Mercury. A dark matter
00:01:25 --> 00:01:27 detector recorded one flash it cannot
00:01:27 --> 00:01:28 explain.
00:01:28 --> 00:01:31 >> And brand new this week and genuinely
00:01:31 --> 00:01:34 lovely. Astronomers have watched a comet
00:01:34 --> 00:01:37 switch on 3 billion miles away over 5
00:01:37 --> 00:01:39 years in real time.
00:01:39 --> 00:01:41 >> Plus the sky for the week ahead. Both
00:01:42 --> 00:01:45 hemispheres and it is a dark one in the
00:01:45 --> 00:01:46 good way.
00:01:46 --> 00:01:49 >> It's a big episode. Let's get into it.
00:01:49 --> 00:01:51 >> Right. Start me at the beginning. Who
00:01:51 --> 00:01:55 did what? a team led by Dr. Surro Paul.
00:01:55 --> 00:01:57 He's at the University of Manchester and
00:01:57 --> 00:01:59 the University of the Western Cape.
00:01:59 --> 00:02:02 Working with Laura Wols at Jawril Bank,
00:02:02 --> 00:02:04 Mario Santos at the Western Cape and
00:02:04 --> 00:02:07 Xiaoing Chen at Edinburgh. The paper is
00:02:07 --> 00:02:10 in the Astrophysical Journal letters and
00:02:10 --> 00:02:11 Manchester put the release out on
00:02:11 --> 00:02:14 Tuesday. It has been rolling through the
00:02:14 --> 00:02:17 international wires all week. Shinha ran
00:02:17 --> 00:02:18 it yesterday.
00:02:18 --> 00:02:22 >> And the instrument is Mircat. Mircat 64
00:02:22 --> 00:02:24 radio dishes standing in the Karu in
00:02:24 --> 00:02:27 South Africa's northern Cape one of the
00:02:27 --> 00:02:29 quietest patches of radio sky on earth
00:02:29 --> 00:02:31 which turns out to be the whole point
00:02:32 --> 00:02:34 and Mircat is not just a fine telescope
00:02:34 --> 00:02:37 in its own right it's a precursor it
00:02:37 --> 00:02:39 gets absorbed into SKA mid the
00:02:39 --> 00:02:41 mid-frequency half of the square km
00:02:41 --> 00:02:42 array
00:02:42 --> 00:02:45 >> okay now tell me what they detected
00:02:45 --> 00:02:47 because hydrogen on its own doesn't
00:02:47 --> 00:02:49 sound like news
00:02:49 --> 00:02:52 >> it isn't on its zone. Hydrogen is the
00:02:52 --> 00:02:54 most common thing in the universe. The
00:02:54 --> 00:02:56 news is how they detected it and at what
00:02:56 --> 00:02:59 distance. Neutral hydrogen, a lone
00:02:59 --> 00:03:02 proton with a lone electron, emits at a
00:03:02 --> 00:03:06 very specific radio wavelength, 21 cm.
00:03:06 --> 00:03:09 >> The famous 21 cm line,
00:03:09 --> 00:03:11 >> the famous one, and it's famous because
00:03:11 --> 00:03:14 it's reliable. Hydrogen doesn't care
00:03:14 --> 00:03:16 whether it's in a bright galaxy or a dim
00:03:16 --> 00:03:20 one. If it's neutral, it glows at 21 cm,
00:03:20 --> 00:03:23 which makes it in principle the perfect
00:03:23 --> 00:03:26 tracer for where matter actually is.
00:03:26 --> 00:03:27 >> In principle.
00:03:27 --> 00:03:30 >> In principle. In practice, the emission
00:03:30 --> 00:03:33 from any single distant galaxy is far
00:03:33 --> 00:03:36 too faint to pick out. So about 15 years
00:03:36 --> 00:03:38 ago, people proposed a workaround called
00:03:38 --> 00:03:40 intensity mapping. Stop trying to
00:03:40 --> 00:03:43 resolve galaxies. point the telescope at
00:03:43 --> 00:03:45 a big patch of sky, deliberately blur
00:03:45 --> 00:03:48 it, and measure the total 21 cm glow
00:03:48 --> 00:03:50 coming from that whole volume.
00:03:50 --> 00:03:53 >> So instead of a photograph of individual
00:03:53 --> 00:03:56 galaxies, you get what? A heat map.
00:03:56 --> 00:03:58 >> That's exactly the right image, a
00:03:58 --> 00:04:00 lowresolution map of where the hydrogen
00:04:00 --> 00:04:03 is piled up and where it's thin. And
00:04:03 --> 00:04:05 because hydrogen sits inside galaxies
00:04:05 --> 00:04:08 and galaxies sit inside the cosmic web,
00:04:08 --> 00:04:10 that blurry map traces the large scale
00:04:10 --> 00:04:13 structure of the universe cheaply and
00:04:13 --> 00:04:16 over enormous volumes.
00:04:16 --> 00:04:18 >> Why does cheap matter? We have galaxy
00:04:18 --> 00:04:20 surveys.
00:04:20 --> 00:04:21 >> We do, and they're superb, but they're
00:04:21 --> 00:04:24 expensive in telescope time. To map
00:04:24 --> 00:04:25 structure optically, you have to
00:04:26 --> 00:04:27 identify each galaxy and measure its
00:04:27 --> 00:04:30 distance one at a time, millions of
00:04:30 --> 00:04:33 them. Intensity mapping says I don't
00:04:33 --> 00:04:35 need to know which galaxy is which. I
00:04:35 --> 00:04:37 only need to know how much hydrogen is
00:04:37 --> 00:04:40 in this cube of space versus that one.
00:04:40 --> 00:04:41 And if you can do that out to high red
00:04:42 --> 00:04:44 shift you can measure how the universe
00:04:44 --> 00:04:46 has expanded which is the dark energy
00:04:46 --> 00:04:47 question.
00:04:47 --> 00:04:49 >> So why hasn't anyone done it?
00:04:49 --> 00:04:51 >> Because of the foregrounds. And this is
00:04:51 --> 00:04:53 the part I want to be precise about. The
00:04:53 --> 00:04:56 21 cm signal from those distant galaxies
00:04:56 --> 00:04:59 is extraordinarily faint. Sitting on top
00:04:59 --> 00:05:01 of it is radio emission from our own
00:05:01 --> 00:05:04 Milky Way. Synretron radiation,
00:05:04 --> 00:05:06 electrons spiraling in the galaxy's
00:05:06 --> 00:05:09 magnetic field. And that is roughly four
00:05:09 --> 00:05:11 orders of magnitude brighter than the
00:05:11 --> 00:05:13 thing you're trying to measure.
00:05:13 --> 00:05:15 >> 10 times.
00:05:15 --> 00:05:17 >> 10 times, give or take. then add
00:05:17 --> 00:05:20 human radio interference, satellites,
00:05:20 --> 00:05:22 aircraft, mobile networks, and then add
00:05:22 --> 00:05:24 the telescope's own quirks, which
00:05:24 --> 00:05:26 imprint themselves on the data in ways
00:05:26 --> 00:05:29 that look deceptively like signal.
00:05:29 --> 00:05:31 Paul's line in the release is the honest
00:05:31 --> 00:05:33 one. The signal is extremely faint and
00:05:33 --> 00:05:35 difficult to isolate from foreground
00:05:35 --> 00:05:38 emission, human-made radio frequency
00:05:38 --> 00:05:41 interference, and instrumental effects.
00:05:41 --> 00:05:42 >> So, how have people got around that
00:05:42 --> 00:05:45 until now? By cheating slightly, and I
00:05:45 --> 00:05:47 mean that admiringly, you take your
00:05:47 --> 00:05:49 radio map and you crossorrelate it with
00:05:49 --> 00:05:51 an optical galaxy survey of the same
00:05:51 --> 00:05:54 patch of sky. You already know where the
00:05:54 --> 00:05:56 galaxies are from the optical data. So
00:05:56 --> 00:05:58 you ask, does the radio map get brighter
00:05:58 --> 00:06:00 in the places the optical survey says
00:06:00 --> 00:06:02 galaxies live?
00:06:02 --> 00:06:04 >> And if it does, that's the hydrogen.
00:06:04 --> 00:06:06 >> That's the hydrogen. It's a legitimate
00:06:06 --> 00:06:09 detection, and Mircat and its
00:06:09 --> 00:06:11 predecessors have done it before, but it
00:06:11 --> 00:06:13 has a built-in limit.
00:06:13 --> 00:06:16 The foreground contamination and your
00:06:16 --> 00:06:18 instrumental noise don't know where the
00:06:18 --> 00:06:21 optical galaxies are. So they average
00:06:21 --> 00:06:23 away in the crossorrelation,
00:06:23 --> 00:06:25 which is wonderful for confidence and
00:06:25 --> 00:06:28 useless if what you actually want is a
00:06:28 --> 00:06:30 standalone survey. You're always
00:06:30 --> 00:06:33 tethered to an optical telescope.
00:06:33 --> 00:06:36 >> And this week they cut the tether.
00:06:36 --> 00:06:40 >> This week they cut the tether. This is
00:06:40 --> 00:06:43 the 21 cm signal measured in the radio
00:06:43 --> 00:06:46 data alone. No optical survey propping
00:06:46 --> 00:06:49 it up. The foregrounds had to be
00:06:49 --> 00:06:51 genuinely removed rather than
00:06:51 --> 00:06:53 statistically dodged. And what's left is
00:06:54 --> 00:06:56 a real measurement of the hydrogen
00:06:56 --> 00:06:57 distribution.
00:06:57 --> 00:06:59 >> How much observing time did that take?
00:06:59 --> 00:07:02 >> Here's the part that made me sit up.
00:07:02 --> 00:07:05 About 96 hours.
00:07:05 --> 00:07:08 4 days of telescope time. That's
00:07:08 --> 00:07:09 nothing.
00:07:09 --> 00:07:12 >> And it gets better. Santos's quote is my
00:07:12 --> 00:07:14 favorite line in the whole release. It
00:07:14 --> 00:07:17 is particularly remarkable that the data
00:07:17 --> 00:07:20 used in this study were taken in 2018
00:07:20 --> 00:07:22 when Mircat had only just started
00:07:22 --> 00:07:23 science operations.
00:07:23 --> 00:07:26 >> Wait, the data is 8 years old.
00:07:26 --> 00:07:29 >> The data is 8 years old. This is not a
00:07:29 --> 00:07:31 new observing campaign. This is a brand
00:07:31 --> 00:07:33 new analysis of some of the first
00:07:33 --> 00:07:36 science data Mircat ever took. And the
00:07:36 --> 00:07:38 advance is in the method, the foreground
00:07:38 --> 00:07:40 removal, the handling of the
00:07:40 --> 00:07:42 instrument's own systematics, the
00:07:42 --> 00:07:45 pipeline. The telescope was always
00:07:45 --> 00:07:46 capable. We weren't.
00:07:46 --> 00:07:49 >> How far back are we actually looking?
00:07:49 --> 00:07:52 >> The emission has been traveling 4 to 5
00:07:52 --> 00:07:54 billion years. So, we're seeing the
00:07:54 --> 00:07:56 hydrogen as it was when the universe was
00:07:56 --> 00:07:59 around 9 billion years old, roughly a
00:07:59 --> 00:08:01 third of its present age ago and well
00:08:01 --> 00:08:04 into the era when dark energy had taken
00:08:04 --> 00:08:07 over and the expansion was accelerating.
00:08:07 --> 00:08:09 That is exactly the epoch you want if
00:08:09 --> 00:08:11 you're trying to test how dark energy
00:08:11 --> 00:08:12 behaves over time.
00:08:12 --> 00:08:14 >> And the structures they're mapping are
00:08:14 --> 00:08:15 big,
00:08:15 --> 00:08:18 >> enormous. The scales involved are
00:08:18 --> 00:08:20 comparable to the gap between us and
00:08:20 --> 00:08:22 Andromeda, millions of light years,
00:08:22 --> 00:08:24 which is precisely the size range where
00:08:24 --> 00:08:27 the cosmic webs.
00:08:27 --> 00:08:29 >> All right. Southern hemisphere angle
00:08:29 --> 00:08:32 because I know there is one and I know
00:08:32 --> 00:08:33 you're saving it.
00:08:33 --> 00:08:36 >> I am. And it's not a footnote. It's the
00:08:36 --> 00:08:39 entire future of this field. The square
00:08:39 --> 00:08:41 kilometer array observatory is being
00:08:41 --> 00:08:44 built in two halves. Both of them in the
00:08:44 --> 00:08:47 south. SKA mid is going up in the KU
00:08:47 --> 00:08:49 alongside and incorporating Mircat
00:08:49 --> 00:08:52 itself. SKA low is going up at
00:08:52 --> 00:08:56 Inyuramana Ilgari Bundara, the CSRO
00:08:56 --> 00:08:58 Merchesen radioastronomy observatory in
00:08:58 --> 00:09:01 Western Australia on Wajari Yamamaji
00:09:01 --> 00:09:02 country.
00:09:02 --> 00:09:04 >> So this technique's proving ground and
00:09:04 --> 00:09:07 its future home are both in the southern
00:09:07 --> 00:09:07 hemisphere
00:09:07 --> 00:09:10 >> both. And that's not an accident of
00:09:10 --> 00:09:14 politics. its radio quietness and its
00:09:14 --> 00:09:17 geography. You cannot do this from a
00:09:17 --> 00:09:20 populated continent. The signal is too
00:09:20 --> 00:09:22 faint. You need somewhere with legally
00:09:22 --> 00:09:25 protected radio silence, and both the
00:09:25 --> 00:09:27 Karu and the Merchesen have exactly
00:09:27 --> 00:09:31 that. WS's line is the forward-looking
00:09:31 --> 00:09:34 one. Mircat continues to open new
00:09:34 --> 00:09:36 windows for cosmology, and the point of
00:09:36 --> 00:09:38 a precursor is that everything you learn
00:09:38 --> 00:09:41 on it, you carry across.
00:09:41 --> 00:09:44 So, what does the SKA do with a working
00:09:44 --> 00:09:45 version of this?
00:09:45 --> 00:09:48 >> Surveys of a size that simply aren't
00:09:48 --> 00:09:51 available any other way. If 96 hours on
00:09:51 --> 00:09:54 64 dishes gets you a detection, then
00:09:54 --> 00:09:56 thousands of hours on an array with
00:09:56 --> 00:09:58 vastly more collecting area gets you a
00:09:58 --> 00:10:01 map. A three-dimensional hydrogen map
00:10:01 --> 00:10:03 running across billions of years of
00:10:03 --> 00:10:05 cosmic time measuring the expansion
00:10:05 --> 00:10:08 history directly. That's a dark energy
00:10:08 --> 00:10:10 experiment done with radio waves from
00:10:10 --> 00:10:13 the southern half of the planet.
00:10:13 --> 00:10:16 >> And the honest caveat because you always
00:10:16 --> 00:10:17 have one.
00:10:17 --> 00:10:20 >> Two. First, this is a detection of the
00:10:20 --> 00:10:23 signal, not yet a precision cosmological
00:10:23 --> 00:10:25 measurement. The error bars are wide and
00:10:25 --> 00:10:27 turning this into competitive
00:10:27 --> 00:10:29 constraints on dark energy is a longer
00:10:29 --> 00:10:32 road. Second, foreground removal is the
00:10:32 --> 00:10:33 kind of problem that has embarrassed
00:10:33 --> 00:10:37 radio astronomy before. The 21 cm
00:10:37 --> 00:10:38 cosmology field has had claimed
00:10:38 --> 00:10:41 detections walked back. The reason this
00:10:41 --> 00:10:43 one is being taken seriously is the
00:10:43 --> 00:10:45 crossorrelation groundwork underneath
00:10:45 --> 00:10:48 it. They had already shown they could
00:10:48 --> 00:10:50 find the signal the safe way before they
00:10:50 --> 00:10:52 went looking for it the hard way.
00:10:52 --> 00:10:54 >> Which is the right order to do things
00:10:54 --> 00:10:55 in.
00:10:55 --> 00:10:57 >> It's exactly the right order and it's
00:10:57 --> 00:10:59 why Paul's summary is the sentence to
00:10:59 --> 00:11:02 take away. Detecting it directly with
00:11:02 --> 00:11:04 Mircat shows that this technique is
00:11:04 --> 00:11:07 becoming a practical tool for cosmology.
00:11:07 --> 00:11:11 Not a promising idea anymore, a tool.
00:11:11 --> 00:11:14 >> Right. Monday to Friday, the six stories
00:11:14 --> 00:11:16 that mattered. And three of them have
00:11:16 --> 00:11:18 moved since we covered them.
00:11:18 --> 00:11:21 >> We start where we ended last weekend.
00:11:21 --> 00:11:23 The Nancy Grace Roman Space Telescope
00:11:23 --> 00:11:25 launched on Sunday, August 30th on a
00:11:26 --> 00:11:29 Falcon Heavy out of launch complex 39A,
00:11:29 --> 00:11:31 and it was clean. No anomalies, straight
00:11:32 --> 00:11:34 up, right on the money. We led Monday's
00:11:34 --> 00:11:36 episode with it, and that closed an arc
00:11:36 --> 00:11:37 we'd been building since the 25th of
00:11:37 --> 00:11:39 August.
00:11:39 --> 00:11:41 >> But it hasn't stopped being a story.
00:11:41 --> 00:11:44 >> It hasn't. On Tuesday, NASA powered on
00:11:44 --> 00:11:46 the Roman coronagraph instrument for the
00:11:46 --> 00:11:49 first time. It came alive between 7:27
00:11:49 --> 00:11:52 and 8:22 in the morning, Eastern time.
00:11:52 --> 00:11:54 That's the technology demonstration that
00:11:54 --> 00:11:56 blocks the light of a star so you can
00:11:56 --> 00:11:58 photograph the planets around it.
00:11:58 --> 00:11:59 >> Which is the hard part.
00:11:59 --> 00:12:01 >> Absurdly hard. You're trying to see
00:12:02 --> 00:12:04 something a billion times fainter than
00:12:04 --> 00:12:06 the thing sitting right next to it. The
00:12:06 --> 00:12:09 coronagraph does it with masks, sensors,
00:12:09 --> 00:12:11 and mirrors that flex themselves in real
00:12:11 --> 00:12:14 time to cancel out scattered starlight.
00:12:14 --> 00:12:16 And what it's after is a class of planet
00:12:16 --> 00:12:19 we've barely photographed. Worlds that
00:12:19 --> 00:12:22 are older, colder, and in closer orbits
00:12:22 --> 00:12:25 than the hot, young super Jupiters that
00:12:25 --> 00:12:27 direct imaging has managed so far.
00:12:27 --> 00:12:30 >> How long before it produces anything?
00:12:30 --> 00:12:33 >> Months. It goes into a long calibration
00:12:33 --> 00:12:35 campaign, and its observing is spread
00:12:35 --> 00:12:38 across roughly 3 months of time inside
00:12:38 --> 00:12:40 the mission's first year and a half. So
00:12:40 --> 00:12:43 don't expect pictures soon. But the
00:12:43 --> 00:12:45 instrument is awake and that's the
00:12:45 --> 00:12:46 milestone.
00:12:46 --> 00:12:49 >> On Tuesday, we led on Starship flight 14
00:12:49 --> 00:12:52 and the news then was that booster 21
00:12:52 --> 00:12:55 had cleared its 33 engine static fire
00:12:55 --> 00:12:58 and ship 41 static fire was already
00:12:58 --> 00:13:00 done. What we could not give you was a
00:13:00 --> 00:13:01 date.
00:13:01 --> 00:13:02 >> And now there's one.
00:13:02 --> 00:13:05 >> There's one with a caveat I want to put
00:13:05 --> 00:13:08 up front. An FCC filing points to launch
00:13:08 --> 00:13:11 no earlier than September 15th. and the
00:13:11 --> 00:13:14 launch trackers have moved to that date.
00:13:14 --> 00:13:16 SpaceX itself has not stood up and
00:13:16 --> 00:13:20 confirmed it. So net the 15th from pad 2
00:13:20 --> 00:13:23 at Starbase and treat it as a strong
00:13:23 --> 00:13:26 indication rather than a promise.
00:13:26 --> 00:13:27 >> And this is the big one.
00:13:27 --> 00:13:30 >> This is the big one on two counts. It's
00:13:30 --> 00:13:32 build as the first genuinely orbital
00:13:32 --> 00:13:35 flight of Starship. Previous test
00:13:35 --> 00:13:36 flights have flown trajectories that
00:13:36 --> 00:13:38 deliberately stopped short of orbit, so
00:13:38 --> 00:13:41 the vehicle came down regardless. And it
00:13:41 --> 00:13:43 carries the first ever attempt to catch
00:13:43 --> 00:13:46 the ship itself. Not the booster, the
00:13:46 --> 00:13:49 upper stage back at the tower into the
00:13:49 --> 00:13:49 arms.
00:13:49 --> 00:13:52 >> They've caught boosters repeatedly now.
00:13:52 --> 00:13:54 >> They have. And it stopped being
00:13:54 --> 00:13:56 astonishing faster than it should have.
00:13:56 --> 00:13:59 But the ship is a different animal. It
00:13:59 --> 00:14:01 comes back from orbital velocity through
00:14:01 --> 00:14:03 the worst of the heating. and it has to
00:14:03 --> 00:14:05 arrive at a precise point with enough
00:14:05 --> 00:14:08 control authority left to be grabbed. If
00:14:08 --> 00:14:10 that works on the first try, it will be
00:14:10 --> 00:14:12 one of the more remarkable things this
00:14:12 --> 00:14:13 vehicle has done.
00:14:13 --> 00:14:15 >> And if it doesn't,
00:14:15 --> 00:14:17 >> then it's a test flight. And that's what
00:14:17 --> 00:14:20 test flights are for. 10 days out,
00:14:20 --> 00:14:23 weather and paperwork permitting.
00:14:23 --> 00:14:24 >> Wednesday's lead was the one I keep
00:14:24 --> 00:14:27 thinking about. A paper in Nature
00:14:27 --> 00:14:30 published on August 27th, led by Burn
00:14:30 --> 00:14:32 and colleagues, built out of years of
00:14:32 --> 00:14:34 accumulated radio tracking of three NASA
00:14:34 --> 00:14:38 spacecraft, Mars Global Surveyor, Mars
00:14:38 --> 00:14:40 Odyssey, and the Mars Reconnaissance
00:14:40 --> 00:14:41 Orbiter.
00:14:41 --> 00:14:43 >> And the technique was the clever bit,
00:14:44 --> 00:14:46 >> title tomography. The sun and Phobos
00:14:46 --> 00:14:49 flex Mars very slightly, and how much a
00:14:49 --> 00:14:51 planet flexes depends on how stiff it is
00:14:51 --> 00:14:53 inside. So if you track your orbiters
00:14:53 --> 00:14:56 precisely enough for long enough, the
00:14:56 --> 00:14:58 wobble in their orbits tells you about
00:14:58 --> 00:15:00 the rigidity of the rock beneath them.
00:15:00 --> 00:15:03 It's seismology without a seismometer.
00:15:03 --> 00:15:04 >> And what did it find?
00:15:04 --> 00:15:06 >> That the interior beneath the southern
00:15:06 --> 00:15:09 highlands is somewhere between 200 and
00:15:09 --> 00:15:12 400° C hotter than the north and
00:15:12 --> 00:15:15 partially molten, which is not a small
00:15:15 --> 00:15:19 asymmetry. That's one planet with two
00:15:19 --> 00:15:21 different interiors.
00:15:21 --> 00:15:23 Does that explain anything we've been
00:15:23 --> 00:15:24 stuck on?
00:15:24 --> 00:15:26 >> Potentially three things at once, which
00:15:26 --> 00:15:29 is why it's such a satisfying result.
00:15:29 --> 00:15:31 The crust dichotomy, why the southern
00:15:31 --> 00:15:33 highlands sit kilome above the northern
00:15:33 --> 00:15:36 lowlands. The crust magnetic anomalies,
00:15:36 --> 00:15:38 which are overwhelmingly a southern
00:15:38 --> 00:15:41 phenomenon, and a puzzle from insight,
00:15:41 --> 00:15:42 where seismic waves were damped more
00:15:42 --> 00:15:45 than the models predicted. A hotter,
00:15:45 --> 00:15:47 partly molten south is a candidate
00:15:47 --> 00:15:50 answer to all three. And what caused it?
00:15:50 --> 00:15:54 >> Open. A giant impact early on, lopsided
00:15:54 --> 00:15:56 convection in the mantle, or a layer
00:15:56 --> 00:15:59 down there trapping heat. The paper
00:15:59 --> 00:16:01 doesn't pick one, and I respect that.
00:16:01 --> 00:16:04 >> Moving on to Thursday, and one of those
00:16:04 --> 00:16:06 quiet, irreversible moments. Bey
00:16:06 --> 00:16:09 Columbbo, the joint European and
00:16:09 --> 00:16:11 Japanese mission to Mercury separated
00:16:11 --> 00:16:13 from its Mercury transfer module on
00:16:13 --> 00:16:15 Wednesday the 3rd.
00:16:15 --> 00:16:17 >> 8 years to get to that point.
00:16:17 --> 00:16:20 >> 8 years. and nine planetary flybys.
00:16:20 --> 00:16:23 Using gravity to shed speed, because
00:16:23 --> 00:16:25 falling toward the sun is the easy part,
00:16:25 --> 00:16:27 and arriving slowly enough to be
00:16:27 --> 00:16:30 captured is the hard part. The transfer
00:16:30 --> 00:16:33 module is the ion propulsion bus that
00:16:33 --> 00:16:36 did all that work, including working
00:16:36 --> 00:16:38 around a thruster power fault that
00:16:38 --> 00:16:40 forced the arrival to be redesigned. And
00:16:40 --> 00:16:43 once you let it go, you don't get it
00:16:43 --> 00:16:44 back.
00:16:44 --> 00:16:46 >> So, what's the timeline now? gravity
00:16:46 --> 00:16:50 capture at Mercury on November 21st.
00:16:50 --> 00:16:52 Then the two orbiters go their separate
00:16:52 --> 00:16:55 ways. Japan's MO is released around the
00:16:55 --> 00:16:58 9th or 10th of December. Europe's
00:16:58 --> 00:17:00 Mercury planetary orbiter reaches its
00:17:00 --> 00:17:03 final science orbit on the 10th of March
00:17:03 --> 00:17:06 next year, and routine science begins on
00:17:06 --> 00:17:07 the 6th of April.
00:17:07 --> 00:17:09 >> So, this is the start of the arrival,
00:17:09 --> 00:17:11 not the end of the cruise.
00:17:11 --> 00:17:14 >> Precisely. And there are follow-up beats
00:17:14 --> 00:17:16 all the way through. This is a story
00:17:16 --> 00:17:18 we'll be coming back to for the next
00:17:18 --> 00:17:20 seven months.
00:17:20 --> 00:17:21 >> And yesterday, the story with the
00:17:21 --> 00:17:23 biggest headlines and the smallest
00:17:23 --> 00:17:25 number attached to it. The LZ
00:17:25 --> 00:17:29 collaboration, Lux Zeppelin, 10 tons of
00:17:29 --> 00:17:32 liquid xenon a mile under South Dakota,
00:17:32 --> 00:17:35 reported a single nuclear recoil event
00:17:35 --> 00:17:37 they cannot explain. In a place where
00:17:37 --> 00:17:40 dark matter could plausibly show up
00:17:40 --> 00:17:43 >> in exactly that place with essentially
00:17:43 --> 00:17:46 zero expected background in 220 days of
00:17:46 --> 00:17:50 data from 2023 and 2024. It was
00:17:50 --> 00:17:52 announced at TEV particle astrophysics
00:17:52 --> 00:17:55 in Chiba. Brown University released it
00:17:55 --> 00:17:57 on Tuesday and the paper has gone to
00:17:57 --> 00:17:59 physical review letters
00:17:59 --> 00:18:00 >> and the number
00:18:00 --> 00:18:05 >> 2.6 sigma globally 3.4 locally. Physics
00:18:05 --> 00:18:07 calls something a discovery at five. So
00:18:07 --> 00:18:10 this is an anomaly. And to LZ's enormous
00:18:10 --> 00:18:12 credit, they have published it as an
00:18:12 --> 00:18:14 anomaly. Rick Gateskull's line was that
00:18:14 --> 00:18:16 with only one event, they are not
00:18:16 --> 00:18:18 claiming to have seen dark matter.
00:18:18 --> 00:18:20 >> If people take one thing from
00:18:20 --> 00:18:21 yesterday's episode,
00:18:21 --> 00:18:23 >> let it be the difference between local
00:18:23 --> 00:18:27 and global significance. Local asks how
00:18:27 --> 00:18:29 surprising the event is at one specific
00:18:29 --> 00:18:32 mass and energy. Global asks how
00:18:32 --> 00:18:34 surprising it is that you found
00:18:34 --> 00:18:36 something odd anywhere in the whole
00:18:36 --> 00:18:38 range you searched. Account for the size
00:18:38 --> 00:18:40 of the haystack and the surprise
00:18:40 --> 00:18:42 shrinks. That gap is the reason the
00:18:42 --> 00:18:44 honest number is 2.6
00:18:44 --> 00:18:47 >> and the southern angle briefly because
00:18:47 --> 00:18:48 it's a good one.
00:18:48 --> 00:18:51 >> CUPL the Stell Underground Physics
00:18:51 --> 00:18:53 Laboratory a kilometer down a working
00:18:53 --> 00:18:56 gold mine in Western Victoria and the
00:18:56 --> 00:18:57 only underground physics lab in the
00:18:58 --> 00:18:59 southern hemisphere. Its first
00:18:59 --> 00:19:02 experiment, Saber South, installs late
00:19:02 --> 00:19:05 this year to test a 20-year-old Italian
00:19:05 --> 00:19:07 claim from Reversed Seasons, which is a
00:19:07 --> 00:19:09 genuinely elegant piece of experimental
00:19:10 --> 00:19:10 design.
00:19:10 --> 00:19:13 >> And to finish, something new that we
00:19:13 --> 00:19:15 didn't get to during the week, and it's
00:19:15 --> 00:19:17 my favorite thing on the list.
00:19:17 --> 00:19:19 Astronomers have watched a comet switch
00:19:19 --> 00:19:20 on
00:19:20 --> 00:19:22 >> watched present tense
00:19:22 --> 00:19:26 >> over 5 years. The object is 450p
00:19:26 --> 00:19:30 Lonios. It's a centaur. And centaurs are
00:19:30 --> 00:19:33 the in between population. Icy bodies
00:19:33 --> 00:19:35 out among the giant planets that used to
00:19:36 --> 00:19:38 live in the Kyper Belt and are on their
00:19:38 --> 00:19:41 way over enormous time scales to
00:19:41 --> 00:19:43 becoming the short period comets we
00:19:43 --> 00:19:44 recognize.
00:19:44 --> 00:19:46 >> So they're comets in waiting.
00:19:46 --> 00:19:48 >> Comets in waiting. And normally we catch
00:19:48 --> 00:19:51 them at one end or the other. Catching
00:19:51 --> 00:19:55 one mid-transition is rare. The work is
00:19:55 --> 00:19:56 out of the University of Central
00:19:56 --> 00:19:59 Florida, Charles Shambo leading with
00:19:59 --> 00:20:02 Maria Wulmarmac, Yan Fernandez, and
00:20:02 --> 00:20:04 Aaron Beck. And it's been accepted by
00:20:04 --> 00:20:07 the Planetary Science Journal released
00:20:07 --> 00:20:09 on Tuesday.
00:20:09 --> 00:20:10 >> How far out is it?
00:20:10 --> 00:20:13 >> Over 3 billion miles. And using the
00:20:13 --> 00:20:16 James Webb Space Telescope together with
00:20:16 --> 00:20:18 Gemini North, they detected carbon
00:20:18 --> 00:20:22 dioxide gas, icy dust, and thermal
00:20:22 --> 00:20:24 activity around it. And a coma that
00:20:24 --> 00:20:27 grows visibly across observations from
00:20:27 --> 00:20:30 2019 to 2024.
00:20:30 --> 00:20:32 >> So what's turning it on? It's nowhere
00:20:32 --> 00:20:33 near the sun.
00:20:33 --> 00:20:35 >> It doesn't need to be. And this is the
00:20:35 --> 00:20:39 lovely bit of physics. Out in the cold,
00:20:39 --> 00:20:41 water ice freezes into an amorphous
00:20:41 --> 00:20:45 form. disordered glassy with other gases
00:20:45 --> 00:20:47 trapped inside the structure. Warm it
00:20:48 --> 00:20:50 gently and it rearranges into proper
00:20:50 --> 00:20:53 crystallin ice. That transition releases
00:20:53 --> 00:20:56 the trapped gas, carbon dioxide in this
00:20:56 --> 00:20:59 case, and that's what's blowing the coma
00:20:59 --> 00:21:00 out.
00:21:00 --> 00:21:01 >> And they can see that the ice has
00:21:01 --> 00:21:02 changed.
00:21:02 --> 00:21:04 >> They found crystallin water ice in the
00:21:04 --> 00:21:07 coma, which is the fingerprint. And a
00:21:07 --> 00:21:09 Saturn encounter appears to be what
00:21:09 --> 00:21:11 nudged the object onto the path that
00:21:11 --> 00:21:14 started warming it in the first place.
00:21:14 --> 00:21:17 So you get the whole causal chain. A
00:21:17 --> 00:21:19 gravitational nudge from a giant planet,
00:21:19 --> 00:21:22 a slow warming, a phase change in the
00:21:22 --> 00:21:25 ice, and a comet is born.
00:21:25 --> 00:21:27 >> 3 billion miles away. And we watched it
00:21:27 --> 00:21:28 happen.
00:21:28 --> 00:21:30 >> We watched it happen.
00:21:30 --> 00:21:32 >> Let's move on to our skywatch segment.
00:21:32 --> 00:21:33 And this is a good week to actually get
00:21:33 --> 00:21:36 outside because the moon is getting out
00:21:36 --> 00:21:38 of the way. Last quarter was yesterday.
00:21:38 --> 00:21:41 >> Last quarter yesterday. And new moon on
00:21:41 --> 00:21:44 Friday the 11th. So every night this
00:21:44 --> 00:21:47 week, the moon rises later and thinner
00:21:47 --> 00:21:50 and the evening sky is dark. If you have
00:21:50 --> 00:21:51 been putting off looking at something
00:21:51 --> 00:21:54 faint, this is the week.
00:21:54 --> 00:21:55 >> Southern hemisphere first.
00:21:55 --> 00:21:57 >> Southern hemisphere first because
00:21:57 --> 00:21:59 September is our last really good month
00:21:59 --> 00:22:01 for it. From Sydney, the sun sets just
00:22:01 --> 00:22:04 before a/4 to 6. And once it's properly
00:22:04 --> 00:22:06 dark, the center of the Milky Way is
00:22:06 --> 00:22:09 almost directly overhead. Sagittarius
00:22:09 --> 00:22:12 and Scorpius at the zenith. That means
00:22:12 --> 00:22:13 you're looking through the least
00:22:13 --> 00:22:15 atmosphere possible at the richest part
00:22:15 --> 00:22:17 of our galaxy.
00:22:17 --> 00:22:19 >> What do people actually point at?
00:22:19 --> 00:22:21 >> Find the teapot of Sagittarius with the
00:22:21 --> 00:22:24 naked eye and follow the steam up out of
00:22:24 --> 00:22:27 the spout. That's the galactic center.
00:22:27 --> 00:22:29 Binoculars turn it into star clouds and
00:22:29 --> 00:22:32 dark dust lanes. and the Lagoon Nebula
00:22:32 --> 00:22:34 and a whole run of globular clusters are
00:22:34 --> 00:22:37 sitting right there. Then later in the
00:22:37 --> 00:22:40 evening, the Magelanic clouds climb up
00:22:40 --> 00:22:43 in the southeast and 47 Tucan is
00:22:43 --> 00:22:45 arguably the finest globular cluster in
00:22:45 --> 00:22:46 the sky.
00:22:46 --> 00:22:47 >> Planets down here,
00:22:47 --> 00:22:50 >> Venus low in the west after sunset,
00:22:50 --> 00:22:52 brilliant, unmistakable, and building
00:22:52 --> 00:22:54 toward greatest brilliancancy on the
00:22:54 --> 00:22:58 18th at magnitude 4.8. Saturn is up most
00:22:58 --> 00:23:00 of the night in Aquarius, heading for
00:23:00 --> 00:23:03 opposition on October 4th. And from the
00:23:03 --> 00:23:05 south, it rides far higher than it does
00:23:05 --> 00:23:07 for northern observers. And Jupiter is
00:23:07 --> 00:23:10 the pre-dawn showpiece in the east.
00:23:10 --> 00:23:12 >> Anything to circle in the diary?
00:23:12 --> 00:23:15 >> Tomorrow morning, Sunday the 6th, a thin
00:23:15 --> 00:23:17 waning crescent moon sits a few degrees
00:23:17 --> 00:23:19 from Mars in the pre-dawn sky. A nice
00:23:19 --> 00:23:22 one for a phone camera. Monday, the moon
00:23:22 --> 00:23:24 moves on to Pollock
00:23:24 --> 00:23:27 >> and North America gets the proper event.
00:23:27 --> 00:23:29 Tuesday the 8th, the moon occults
00:23:29 --> 00:23:32 Jupiter. The planet passes behind the
00:23:32 --> 00:23:35 lunar disc. The footprint covers Canada,
00:23:35 --> 00:23:38 Greenland, the United States, Eastern
00:23:38 --> 00:23:40 Russia, and the North Pacific. And for
00:23:40 --> 00:23:42 much of eastern North America, it
00:23:42 --> 00:23:45 happens after sunrise in broad daylight.
00:23:45 --> 00:23:46 >> Daylight.
00:23:46 --> 00:23:49 >> Daylight. And that brings the standing
00:23:49 --> 00:23:51 reminder which applies directly here. If
00:23:51 --> 00:23:54 you are observing anywhere near the sun,
00:23:54 --> 00:23:56 hunting Jupiter in a bright sky, or
00:23:56 --> 00:23:58 looking at the sunspots I'm about to
00:23:58 --> 00:24:01 mention, any filter you use for direct
00:24:01 --> 00:24:03 solar viewing must be certified to the
00:24:03 --> 00:24:06 ISO12312-2
00:24:06 --> 00:24:09 standard, not sunglasses, not welding
00:24:09 --> 00:24:11 glass of unknown grade, not smoked
00:24:11 --> 00:24:16 glass, not a phone screen. ISO12312-2
00:24:16 --> 00:24:19 and check the certification is genuine.
00:24:19 --> 00:24:21 Sweeping binoculars or a telescope
00:24:21 --> 00:24:24 across a daylight sky is exactly how
00:24:24 --> 00:24:26 people injure themselves permanently and
00:24:26 --> 00:24:28 it takes a fraction of a second.
00:24:28 --> 00:24:29 >> Meteors,
00:24:29 --> 00:24:32 >> the September epsilon perciads peak on
00:24:32 --> 00:24:34 Wednesday the 9th, a modest shower,
00:24:34 --> 00:24:37 about 8 an hour at best, and it's a
00:24:37 --> 00:24:38 northern hemisphere event with the
00:24:38 --> 00:24:41 radiant in Perseus. But it falls two
00:24:41 --> 00:24:43 nights before new moon. So if you're up
00:24:43 --> 00:24:46 north and you're out anyway, conditions
00:24:46 --> 00:24:48 are as good as that shower ever gets.
00:24:48 --> 00:24:50 And the sun itself
00:24:50 --> 00:24:52 >> busier than last weekend. Active region
00:24:52 --> 00:24:56 4524 has come back around the limb and
00:24:56 --> 00:25:00 fired an M1.2 flare at 7:45 universal
00:25:00 --> 00:25:02 time yesterday with a brief radio
00:25:02 --> 00:25:06 blackout. Region 4523 is growing and
00:25:06 --> 00:25:08 throwing C-class flares. Nothing is
00:25:08 --> 00:25:11 aimed squarely at us. The strongest
00:25:11 --> 00:25:13 eruption went well away from Earth.
00:25:13 --> 00:25:15 >> Aurora chances.
00:25:15 --> 00:25:18 >> Honest answer. Quiet tonight, possibly
00:25:18 --> 00:25:21 unsettled Sunday into Monday. KP 3 to 4
00:25:21 --> 00:25:24 at best. That's a high latitude show
00:25:24 --> 00:25:26 only. Tasmania and southern New Zealand
00:25:26 --> 00:25:29 down here, Scotland and Alaska up there.
00:25:29 --> 00:25:31 Watch the space weather feeds rather
00:25:31 --> 00:25:32 than the headlines.
00:25:32 --> 00:25:35 >> And one for northern binoculars,
00:25:35 --> 00:25:37 >> the double cluster in Perseus while the
00:25:37 --> 00:25:40 moon's away. Naked eye, it's a smudge.
00:25:40 --> 00:25:42 In binoculars, it's two open clusters
00:25:42 --> 00:25:45 side by side in one field. and it's one
00:25:45 --> 00:25:47 of the best sites in the sky.
00:25:47 --> 00:25:49 >> And that's the weekend wrap for
00:25:49 --> 00:25:51 Saturday, September 5th. A radio
00:25:52 --> 00:25:55 telescope in the KU has mapped hydrogen
00:25:55 --> 00:25:58 across 4 to 5 billion lightyear using
00:25:58 --> 00:26:01 nothing but radio waves and proved out
00:26:01 --> 00:26:03 the technique the square kilometer array
00:26:03 --> 00:26:06 will use to measure dark energy from the
00:26:06 --> 00:26:07 southern hemisphere.
00:26:07 --> 00:26:10 >> Roman's coronagraph is awake. Starship
00:26:10 --> 00:26:13 flight 14 is penciled in for the 15th
00:26:13 --> 00:26:15 with the first attempt to catch a ship.
00:26:15 --> 00:26:17 Mars is hotter underneath its southern
00:26:17 --> 00:26:20 half than anyone expected. Bey Columbo
00:26:20 --> 00:26:22 has let go of its transfer module and is
00:26:22 --> 00:26:25 falling toward Mercury. A xenon detector
00:26:25 --> 00:26:27 under South Dakota has one flash it
00:26:27 --> 00:26:29 can't explain and is being admirably
00:26:29 --> 00:26:30 careful about it.
00:26:30 --> 00:26:33 >> And a centaur 3 billion miles away has
00:26:34 --> 00:26:36 spent 5 years quietly turning into a
00:26:36 --> 00:26:39 comet while we watched. Full show notes,
00:26:39 --> 00:26:41 links to every primary source, and the
00:26:41 --> 00:26:43 whole back catalog are at
00:26:43 --> 00:26:45 astronomyaily.io.
00:26:45 --> 00:26:47 >> You'll find us on X, Instagram, and Tik
00:26:47 --> 00:26:50 Tok at astroaily pod. And if you've got
00:26:50 --> 00:26:53 a question or a correction, we want it.
00:26:53 --> 00:26:56 There's a contact form on the website.
00:26:56 --> 00:26:58 >> If today's episode was useful, the
00:26:58 --> 00:27:00 single most helpful thing you can do is
00:27:00 --> 00:27:03 send it to one person who'd enjoy it.
00:27:03 --> 00:27:05 >> We're back Monday with the regular
00:27:05 --> 00:27:08 weekday format. Until then, the moon's
00:27:08 --> 00:27:11 out of the way all week. Get outside.
00:27:11 --> 00:27:12 Clear skies.
00:27:12 --> 00:27:14 >> Clear skies.
00:27:14 --> 00:27:16 >> Day
00:27:16 --> 00:27:20 stories told.