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00:00:00 --> 00:00:03 Anna: 60 million stars in a single
00:00:03 --> 00:00:06 image. Stay with us. Your universe just
00:00:06 --> 00:00:08 got a whole lot bigger.
00:00:08 --> 00:00:11 Avery: Hello, and welcome to Astronomy Daily, your
00:00:11 --> 00:00:13 daily dispatch from the final frontier. I'm,
00:00:13 --> 00:00:14 um, Avery.
00:00:14 --> 00:00:17 Anna: And I'm anna. It's Friday, the 27th of
00:00:17 --> 00:00:20 June, 2026, and we have a
00:00:20 --> 00:00:23 genuinely spectacular edition for you today.
00:00:24 --> 00:00:27 Six stories that together paint a portrait
00:00:27 --> 00:00:29 of just how active and extraordinary
00:00:29 --> 00:00:30 our universe is.
00:00:30 --> 00:00:33 Avery: Right, we've got a record shattering
00:00:33 --> 00:00:36 telescope image, a, uh, cosmic mystery solved
00:00:36 --> 00:00:39 by Hubble, the oldest scar on Earth,
00:00:39 --> 00:00:42 planets that defy everything we thought we
00:00:42 --> 00:00:44 knew about density, a rocket on a collision
00:00:44 --> 00:00:47 course with the Moon, and a space weather
00:00:47 --> 00:00:49 alert for our, uh, Southern Hemisphere
00:00:49 --> 00:00:51 listeners, all in about 25 minutes.
00:00:52 --> 00:00:53 Anna: Let's dive in.
00:00:53 --> 00:00:56 We're starting with an image that is, quite
00:00:56 --> 00:00:58 simply one of the most spectacular
00:00:58 --> 00:01:01 astronomical photographs ever produced.
00:01:01 --> 00:01:04 The European Space Agency has just released
00:01:04 --> 00:01:07 a breathtaking portrait of the heart of our
00:01:07 --> 00:01:10 own galaxy, captured by the Euclid Space
00:01:10 --> 00:01:13 Telescope. And it contains more than 60
00:01:13 --> 00:01:15 million individual stars.
00:01:16 --> 00:01:19 Avery: 60 million stars in a single
00:01:19 --> 00:01:22 frame. Let that settle for a moment. This is
00:01:22 --> 00:01:24 the largest high resolution visible light
00:01:24 --> 00:01:27 image of the Milky Way central bulge ever
00:01:27 --> 00:01:29 made. And it arrived in our news feeds just
00:01:29 --> 00:01:30 this week.
00:01:30 --> 00:01:33 Anna: Euclid, which was originally built to study
00:01:33 --> 00:01:36 dark matter and dark energy by surveying
00:01:36 --> 00:01:38 billions of distant galaxies, took a
00:01:38 --> 00:01:41 remarkable detour. Astronomers
00:01:41 --> 00:01:43 essentially asked it to do something
00:01:43 --> 00:01:45 completely outside its primary mission,
00:01:46 --> 00:01:49 to spend 26 hours staring at the
00:01:49 --> 00:01:51 dense, glittering core of our own
00:01:51 --> 00:01:52 galaxy.
00:01:52 --> 00:01:55 Avery: And it delivered. The resulting mosaic was
00:01:55 --> 00:01:57 stitched together from nine separate
00:01:57 --> 00:01:59 pointings of Euclid's visible light camera.
00:01:59 --> 00:02:02 Each individual pointing covered a patch of
00:02:02 --> 00:02:04 sky larger than the Full Moon. And the
00:02:04 --> 00:02:07 combined Image spans nearly 5 square
00:02:07 --> 00:02:09 degrees. That's the equivalent of about
00:02:09 --> 00:02:12 25 full moons laid side by side.
00:02:13 --> 00:02:15 Anna: What makes it technically remarkable is that
00:02:15 --> 00:02:18 Euclid's sharpness and sensitivity in
00:02:18 --> 00:02:21 visible light is comparable to Hubble's
00:02:21 --> 00:02:23 Wide Field Camera. But Euclid can Image an
00:02:23 --> 00:02:26 area 270 times larger
00:02:26 --> 00:02:29 in a single pointing. So in terms of
00:02:29 --> 00:02:32 sheer scale combined with resolution,
00:02:32 --> 00:02:34 this image is unprecedented.
00:02:34 --> 00:02:37 Avery: And it's not just beautiful science, it's
00:02:37 --> 00:02:39 strategically important. This image is going
00:02:39 --> 00:02:42 to serve as a critical baseline reference for
00:02:42 --> 00:02:44 NASA's Nancy Grace Roman Telescope, which is
00:02:44 --> 00:02:47 due to launch in late August and will conduct
00:02:47 --> 00:02:49 its own Deep Galactic Bold survey beginning
00:02:49 --> 00:02:51 in 2027.
00:02:51 --> 00:02:54 Anna: Roman will search for exoplanets using a
00:02:54 --> 00:02:57 technique called gravitational microlensing,
00:02:57 --> 00:02:59 where a planet passing in front of a, uh,
00:02:59 --> 00:03:02 background star causes a tiny
00:03:02 --> 00:03:05 detectable brightening. To do that, well, you
00:03:05 --> 00:03:07 need to know the precise positions and
00:03:07 --> 00:03:10 movements of all those stars. And that's
00:03:10 --> 00:03:12 exactly what Euclid has now provided.
00:03:12 --> 00:03:15 Avery: One scientist put it beautifully. They said
00:03:15 --> 00:03:18 that in just 24 hours, Euclid captured the
00:03:18 --> 00:03:20 stars involved in all of Roman's future
00:03:20 --> 00:03:23 microlensing events before the planets and
00:03:23 --> 00:03:25 stars have even aligned Euclid. It's like
00:03:25 --> 00:03:27 taking a class photo before the school year
00:03:27 --> 00:03:28 begins.
00:03:28 --> 00:03:31 Anna: The Image also includes 51
00:03:31 --> 00:03:33 known planetary systems, dense
00:03:33 --> 00:03:36 molecular clouds that appear as dramatic
00:03:36 --> 00:03:39 dark patches, glowing emission nebulae,
00:03:39 --> 00:03:42 and young star clusters. And buried in those
00:03:42 --> 00:03:45 60 million stellar data points are
00:03:45 --> 00:03:47 likely thousands of undiscovered worlds
00:03:47 --> 00:03:50 patiently waiting for Roman to find them.
00:03:50 --> 00:03:53 Avery: An extraordinary image and a tremendous
00:03:53 --> 00:03:55 example of telescopes working together.
00:03:55 --> 00:03:56 Bravo, Euclid.
00:03:57 --> 00:03:59 Our second story takes us back much further
00:03:59 --> 00:04:02 in time to the very early universe, when the
00:04:02 --> 00:04:05 cosmos was still shrouded in a thick fog of
00:04:05 --> 00:04:08 neutral hydrogen gas. And the question of how
00:04:08 --> 00:04:10 that fog was lifted has puzzled astronomers
00:04:10 --> 00:04:11 for decades.
00:04:12 --> 00:04:15 Anna: Now, thanks to the Hubble Space Telescope,
00:04:15 --> 00:04:17 working in concert with James Webb and the
00:04:17 --> 00:04:20 Very Large Telescope in Chile, we may
00:04:20 --> 00:04:23 finally have a definitive an. And the
00:04:23 --> 00:04:25 discovery was published this week in the
00:04:25 --> 00:04:26 Astrophysical Journal.
00:04:27 --> 00:04:30 Avery: The galaxy at the center of this story is
00:04:30 --> 00:04:32 called MXDF Z. Uh, 4.
00:04:32 --> 00:04:35 4. Not the most poetic name. But
00:04:35 --> 00:04:38 what it represents is extraordinary.
00:04:38 --> 00:04:41 This galaxy existed just 1.4
00:04:41 --> 00:04:44 billion years after the Big Bang, right at
00:04:44 --> 00:04:46 the tail end of what astronomers call the era
00:04:46 --> 00:04:48 of reionization.
00:04:48 --> 00:04:51 Anna: Let me explain what that means. For the first
00:04:51 --> 00:04:54 billion or so years of the universe, the gas
00:04:54 --> 00:04:56 between stars and galaxies was neutral,
00:04:56 --> 00:04:59 opaque. Ultraviolet light couldn't travel
00:04:59 --> 00:05:01 through it. The universe was essentially
00:05:01 --> 00:05:04 foggy. Then, over hundreds of millions
00:05:04 --> 00:05:07 of years, that fog burned away, and the
00:05:07 --> 00:05:09 cosmos became the transparent,
00:05:09 --> 00:05:12 magnificent expanse we observe today.
00:05:12 --> 00:05:15 Avery: But what burned it away? That has been one of
00:05:15 --> 00:05:17 the great unsolved questions of cosmology.
00:05:18 --> 00:05:21 There were two main enormous black
00:05:21 --> 00:05:23 holes, or the first generations of hot,
00:05:24 --> 00:05:26 massive young stars. This week,
00:05:26 --> 00:05:28 Hubble has delivered the strongest evidence
00:05:29 --> 00:05:30 yet that it was the stars.
00:05:30 --> 00:05:33 Anna: Here's what's remarkable about MXDF Z
00:05:33 --> 00:05:36 4.4. It's about a hundred times
00:05:36 --> 00:05:39 smaller in area than our Milky Way, a
00:05:39 --> 00:05:41 tiny galaxy by any measure. But it's
00:05:41 --> 00:05:44 forming new stars 10 times faster than we
00:05:44 --> 00:05:47 are. And those young, hot, massive stars
00:05:47 --> 00:05:50 are packed into an incredibly compact
00:05:50 --> 00:05:50 cluster.
00:05:50 --> 00:05:52 Avery: Cram enough of those stars into a small
00:05:52 --> 00:05:55 enough space, and you create a furnace.
00:05:56 --> 00:05:58 The team estimates that between 50 and
00:05:58 --> 00:06:01 100% of the intense ultraviolet light from
00:06:01 --> 00:06:04 those stars is actually escaping the
00:06:04 --> 00:06:06 galaxy's gas, punching clean through it and
00:06:06 --> 00:06:09 ionizing the surrounding hydrogen fog.
00:06:09 --> 00:06:12 Anna: And what's more, many of those massive stars
00:06:12 --> 00:06:14 eventually explode as supernovae,
00:06:14 --> 00:06:17 blasting enormous bubbles in the gas that
00:06:17 --> 00:06:20 create even more pathways for the ionizing
00:06:20 --> 00:06:23 light to escape. It's a self reinforcing
00:06:23 --> 00:06:23 process.
00:06:24 --> 00:06:26 Avery: Before this discovery, astronomers had only
00:06:26 --> 00:06:29 found the galaxy emitting this kind of
00:06:29 --> 00:06:31 ionizing light From a time when the universe
00:06:31 --> 00:06:34 was 1.6 billion years old.
00:06:34 --> 00:06:37 MXDF, uh, 4.4 pushes that
00:06:37 --> 00:06:39 back to 1.4 billion years,
00:06:40 --> 00:06:42 closer than ever to the actual era of
00:06:42 --> 00:06:43 realization.
00:06:43 --> 00:06:46 Anna: What was previously considered impossible to
00:06:46 --> 00:06:49 detect because the fog itself was expected
00:06:49 --> 00:06:51 to absorb that ultraviolet light before it
00:06:51 --> 00:06:54 could reach us, has now been directly
00:06:54 --> 00:06:57 observed. This galaxy may be the smoking
00:06:57 --> 00:06:59 gun that solves one of cosmology's most
00:06:59 --> 00:07:01 enduring mysteries.
00:07:01 --> 00:07:04 Avery: And we're only at, uh, story two. Let's keep
00:07:04 --> 00:07:04 going.
00:07:05 --> 00:07:07 Anna: You're listening to Astronomy Daily, season
00:07:07 --> 00:07:10 five, episode 125. If you're
00:07:10 --> 00:07:13 enjoying the show, please subscribe, leave us
00:07:13 --> 00:07:15 a review and share us with a friend who loves
00:07:15 --> 00:07:18 the stars. Find us at astronomydaily
00:07:18 --> 00:07:20 IO and follow us on socials.
00:07:20 --> 00:07:23 Avery: Astronedailypod Ah, here's a story with
00:07:23 --> 00:07:26 the wonderful local flavor. And it's a
00:07:26 --> 00:07:28 genuine scientific detective story.
00:07:28 --> 00:07:31 Anna: Researchers from Curtin University in Western
00:07:31 --> 00:07:34 Australia, working with the Geological Survey
00:07:34 --> 00:07:37 of Western Australia, have finally resolved a
00:07:37 --> 00:07:39 major scientific debate about what is
00:07:39 --> 00:07:42 officially the oldest known asteroid impact
00:07:42 --> 00:07:45 crater on Earth. Their paper was published
00:07:45 --> 00:07:46 this week in the journal Geology.
00:07:47 --> 00:07:50 Avery: The site in question is called the North Pole
00:07:50 --> 00:07:53 Dome. And yes, despite the name, it's not
00:07:53 --> 00:07:55 near any pole. It's in the remote Pilbara
00:07:55 --> 00:07:58 region of Western Australia, one of the most
00:07:58 --> 00:08:00 geologically ancient landscapes on our
00:08:00 --> 00:08:01 planet.
00:08:01 --> 00:08:04 Anna: Hm. For years, scientists debated just how
00:08:04 --> 00:08:06 old this impact structure actually was.
00:08:07 --> 00:08:10 One team estimated it at 3.47
00:08:10 --> 00:08:12 billion years old. Another challenged that,
00:08:13 --> 00:08:15 arguing it was at most 2.7 billion
00:08:15 --> 00:08:18 years old. The truth, it turns out, lies
00:08:18 --> 00:08:21 somewhere in between. And it still makes
00:08:21 --> 00:08:24 North Pole Dome comfortably the oldest impact
00:08:24 --> 00:08:25 crater known on Earth.
00:08:25 --> 00:08:28 Avery: The Curtin team used advanced mineral dating
00:08:28 --> 00:08:31 techniques, specifically focusing on tiny
00:08:31 --> 00:08:34 crystals of zircon, a mineral renowned for
00:08:34 --> 00:08:36 its ability to preserve geological time with
00:08:36 --> 00:08:39 extraordinary precision. Zircon
00:08:39 --> 00:08:42 contains trace amounts of uranium that slowly
00:08:42 --> 00:08:44 decay into lead. And by measuring that
00:08:44 --> 00:08:46 ratio, you can read the clock.
00:08:46 --> 00:08:49 Anna: The zircons at North Pole Dome had
00:08:49 --> 00:08:52 unusual branching skeletal shapes.
00:08:52 --> 00:08:54 The team interpreted these as impact
00:08:55 --> 00:08:57 modified crystals formed when older
00:08:57 --> 00:09:00 zircon was disrupted and partially
00:09:00 --> 00:09:03 remelted by the intense heat and pressure
00:09:03 --> 00:09:06 of an asteroid strike. Those crystals
00:09:06 --> 00:09:08 record an age of approximately
00:09:08 --> 00:09:11 3 billion years
00:09:11 --> 00:09:11 ago.
00:09:12 --> 00:09:14 Avery: To confirm it, they also dated a second
00:09:14 --> 00:09:17 mineral, apatite which formed as hot
00:09:17 --> 00:09:20 fluids moved through the shock damaged rocks
00:09:20 --> 00:09:22 after the impact. Remarkably, both
00:09:22 --> 00:09:25 dating systems gave the same answer. The
00:09:25 --> 00:09:28 North Pole Dome impact occurred around 3
00:09:28 --> 00:09:30 billion years ago, pushing Earth's known
00:09:30 --> 00:09:33 impact record deeper into geological time
00:09:33 --> 00:09:35 than any previously well dated crater.
00:09:36 --> 00:09:39 Anna: To put that in perspective, the next oldest
00:09:39 --> 00:09:41 confirmed impact structure on Earth is the
00:09:41 --> 00:09:44 Yarrabuba Crater, also in Western Australia.
00:09:45 --> 00:09:47 Dated to 2.23 billion years
00:09:47 --> 00:09:50 ago, North Pole Dome beats it by
00:09:50 --> 00:09:52 nearly 800 million years.
00:09:53 --> 00:09:55 Avery: There's also a haunting proximity.
00:09:56 --> 00:09:58 The oldest known traces of life on Earth,
00:09:58 --> 00:10:01 limestone stromatolites made by ancient
00:10:01 --> 00:10:03 bacteria, are found just a few few
00:10:03 --> 00:10:06 kilometers from North Pole Dome. Those
00:10:06 --> 00:10:09 stromatolites are about 3.5 billion
00:10:09 --> 00:10:11 years old. So when this asteroid hit,
00:10:11 --> 00:10:14 life on Earth was already well established,
00:10:14 --> 00:10:15 and it survived.
00:10:16 --> 00:10:18 Anna: The story of Western Australia as a
00:10:18 --> 00:10:21 geological archive of our planet's earliest
00:10:21 --> 00:10:24 history just keeps getting richer.
00:10:24 --> 00:10:27 Truly remarkable science and a wonderful
00:10:27 --> 00:10:29 home story for our Australian listeners.
00:10:30 --> 00:10:32 Now, a story that will make you question
00:10:32 --> 00:10:35 everything you thought you knew about what a
00:10:35 --> 00:10:35 planet can be.
00:10:36 --> 00:10:38 Avery: Researchers led by the University of Oxford,
00:10:38 --> 00:10:41 in collaboration with teams in France and the
00:10:41 --> 00:10:44 UK have confirmed the discovery of two
00:10:44 --> 00:10:47 record breaking exoplanets with densities
00:10:47 --> 00:10:50 so low they are literally lighter than cotton
00:10:50 --> 00:10:52 candy. The paper is published today in the
00:10:52 --> 00:10:55 Monthly Notices of the Royal Astronomical
00:10:55 --> 00:10:55 Society.
00:10:56 --> 00:10:58 Anna: These planets are named TOI
00:10:58 --> 00:11:01 791B and TOI
00:11:02 --> 00:11:04 791C, and they orbit a, uh,
00:11:04 --> 00:11:06 dwarf star located about
00:11:06 --> 00:11:09 1 light years from
00:11:09 --> 00:11:11 Earth in the southern constellation of
00:11:11 --> 00:11:14 Volans. Both planets are roughly the size of
00:11:14 --> 00:11:17 Jupiter, but that's where the similarity
00:11:17 --> 00:11:17 ends.
00:11:18 --> 00:11:20 Avery: Jupiter has an average density of about
00:11:20 --> 00:11:23 1.33 grams per cubic centimeter.
00:11:23 --> 00:11:25 These two planets have densities of
00:11:25 --> 00:11:28 0 grams per cubic
00:11:28 --> 00:11:31 centimeter and 0
00:11:31 --> 00:11:34 grams per cubic centimeter, respectively. To
00:11:34 --> 00:11:36 give you a sense of scale that's less dense
00:11:36 --> 00:11:39 than cotton candy, which typically weighs in
00:11:39 --> 00:11:41 around 0.05. They're more like
00:11:41 --> 00:11:44 enormous gossamer bubbles of gas than
00:11:44 --> 00:11:46 anything we'd traditionally call a planet.
00:11:47 --> 00:11:49 Anna: They've been dubbed superpuff planets, and
00:11:49 --> 00:11:52 only a handful of such objects are known.
00:11:53 --> 00:11:56 Finding two in the same planetary system is
00:11:56 --> 00:11:58 extraordinarily rare. Lead author
00:11:58 --> 00:12:01 Dr. George Dransfield from Oxford
00:12:01 --> 00:12:03 described them as the lightest planets for
00:12:03 --> 00:12:05 their size ever confirmed.
00:12:06 --> 00:12:08 Avery: The discovery required eight years of
00:12:08 --> 00:12:10 observations from telescopes around the
00:12:10 --> 00:12:13 world. Crucially, it relied on data from the
00:12:13 --> 00:12:16 Antarctic Search for Transiting Exoplanets
00:12:16 --> 00:12:19 Telescope, known as ASTEP UH at Concordia
00:12:19 --> 00:12:22 Station in Antarctica. The Antarctic Winter
00:12:22 --> 00:12:24 provided months of continuous darkness,
00:12:25 --> 00:12:27 allowing the team to capture each planet's
00:12:27 --> 00:12:30 transit, its passage across its host star in
00:12:30 --> 00:12:33 a single uninterrupted observation lasting
00:12:33 --> 00:12:36 more than 11 hours. These are the
00:12:36 --> 00:12:38 longest continuous planetary transits ever
00:12:38 --> 00:12:41 observed from the ground in their entirety.
00:12:41 --> 00:12:44 Anna: How planets this enormous can be
00:12:44 --> 00:12:47 so impossibly light is still an open
00:12:47 --> 00:12:49 question. The leading theory is that they
00:12:49 --> 00:12:52 possess vast hydrogen and helium rich
00:12:52 --> 00:12:55 atmospheres that inflate their size while
00:12:55 --> 00:12:58 contributing very little mass. They may also
00:12:58 --> 00:13:00 be slowly losing material as their star's
00:13:00 --> 00:13:03 radiation strips away their outer layers.
00:13:04 --> 00:13:06 Avery: Dr. Dransfield noted that their extremely low
00:13:06 --> 00:13:09 densities make them ideal targets for future
00:13:09 --> 00:13:12 atmospheric study because with so little mass
00:13:12 --> 00:13:14 holding everything together, the atmosphere
00:13:14 --> 00:13:16 should be puffed up and easier to
00:13:16 --> 00:13:18 characterize. With telescopes like James
00:13:18 --> 00:13:21 Webb, we may learn a lot about how planetary
00:13:21 --> 00:13:24 systems form and evolve from these two
00:13:24 --> 00:13:25 unlikely worlds.
00:13:26 --> 00:13:28 Anna: Giant as Jupiter light as a carnival
00:13:28 --> 00:13:31 treat, the universe continues to
00:13:31 --> 00:13:32 outpace our imagination.
00:13:33 --> 00:13:36 Avery: Mark your calendars, because on August 5, the
00:13:36 --> 00:13:38 moon is about to get hit by a piece of a
00:13:38 --> 00:13:39 SpaceX rocket.
00:13:39 --> 00:13:42 Anna: This is not a drill, and it's not a mission.
00:13:42 --> 00:13:44 It's a piece of orbital debris,
00:13:44 --> 00:13:47 specifically the spent upper stage of a
00:13:47 --> 00:13:49 SpaceX Falcon 9 rocket left over from the
00:13:49 --> 00:13:52 January 2025 launch that sent Firefly
00:13:52 --> 00:13:55 Aerospace's Blue Ghost lander and the
00:13:55 --> 00:13:58 Japanese ispace Hakuto R2 mission
00:13:58 --> 00:13:59 lander toward the Moon.
00:13:59 --> 00:14:01 Avery: After delivering its payload, the upper stage
00:14:01 --> 00:14:04 was left on a trajectory with nowhere to go
00:14:04 --> 00:14:06 but eventually into the lunar surface.
00:14:07 --> 00:14:09 Orbital analyst Bill Gray of Project Pluto
00:14:09 --> 00:14:12 tracked it down using his telescope tracking
00:14:12 --> 00:14:14 Software, and in September 2025
00:14:15 --> 00:14:17 he calculated that it would impact the Moon
00:14:17 --> 00:14:20 on or around August 5th this year.
00:14:20 --> 00:14:23 Anna: The stage weighs approximately 4 metric
00:14:23 --> 00:14:25 tons and is traveling at over 2 kilometers
00:14:25 --> 00:14:28 per second. It's expected to strike near
00:14:28 --> 00:14:31 Einstein Crater on the moon's western limb,
00:14:31 --> 00:14:33 though the precise impact point is still
00:14:33 --> 00:14:36 being refined. Another possible target is
00:14:36 --> 00:14:38 Bell Crater, just out of sight on the far
00:14:38 --> 00:14:38 side.
00:14:39 --> 00:14:42 Avery: Now the question everyone wants answered
00:14:42 --> 00:14:44 Will we be able to see it? And the honest
00:14:44 --> 00:14:47 answer from the Experts is maybe.
00:14:48 --> 00:14:50 Anna: NASA's William Cook, Program manager of the
00:14:50 --> 00:14:53 Meteoroid Environment Office at Marshall
00:14:53 --> 00:14:55 Space Flight center, describes the visibility
00:14:55 --> 00:14:58 as very subtle and very,
00:14:58 --> 00:15:01 very hard to see, if not impossible,
00:15:01 --> 00:15:03 but there's always a chance. He notes, that
00:15:03 --> 00:15:06 the impact will kick up enormous amounts of
00:15:06 --> 00:15:09 lunar dust and rock, and if it occurs close
00:15:09 --> 00:15:12 enough to the Moon's limb, a plume of ejected
00:15:12 --> 00:15:14 material rising against the black sky might
00:15:14 --> 00:15:15 be detectable.
00:15:16 --> 00:15:18 Avery: Bill Gray himself has gone through a journey
00:15:18 --> 00:15:21 on this from probably visible to
00:15:21 --> 00:15:24 probably not to maybe. He
00:15:24 --> 00:15:26 says the timing and location of the impact
00:15:26 --> 00:15:28 are still fuzzy by minutes and dozens of
00:15:28 --> 00:15:31 kilometers, but they'll refine that as August
00:15:31 --> 00:15:32 approaches.
00:15:32 --> 00:15:35 Anna: Here's the reassuring part. NASA's Lunar
00:15:35 --> 00:15:37 Reconnaissance Orbiter will be passing over
00:15:37 --> 00:15:39 the projected crash site about seven days
00:15:39 --> 00:15:42 before the impact and again about seven days
00:15:42 --> 00:15:45 after. So even if we can't see the flash from
00:15:45 --> 00:15:48 Earth, we will get before and after images
00:15:48 --> 00:15:50 of the new crater it creates.
00:15:50 --> 00:15:52 Avery: And there's a genuine citizen science
00:15:52 --> 00:15:55 opportunity here, too. A program called
00:15:55 --> 00:15:58 Impact flash, run through NASA's Solar System
00:15:58 --> 00:16:01 Exploration Research Virtual Institute,
00:16:01 --> 00:16:03 is calling on backyard astronomers to watch
00:16:03 --> 00:16:06 and report. Because impact flashes are
00:16:06 --> 00:16:09 so brief and can mimic cosmic ray hits on
00:16:09 --> 00:16:12 camera sensors, having multiple observers in
00:16:12 --> 00:16:14 different locations simultaneously is
00:16:14 --> 00:16:15 enormously valuable.
00:16:15 --> 00:16:18 Anna: It's a fascinating story, a piece of
00:16:18 --> 00:16:20 hardware launched with the explicit purpose
00:16:20 --> 00:16:23 of reaching the Moon, but in a completely
00:16:23 --> 00:16:25 different way to how its passengers got
00:16:25 --> 00:16:27 there. Another reminder, as one NASA
00:16:27 --> 00:16:30 scientist put it, that the Moon is a dynamic,
00:16:30 --> 00:16:33 ever changing environment, and we are
00:16:33 --> 00:16:34 contributing to that change.
00:16:35 --> 00:16:38 Avery: Set a reminder for August 5th. It might be
00:16:38 --> 00:16:39 history in the making.
00:16:39 --> 00:16:41 Anna: Now it's time for your skywatching update,
00:16:42 --> 00:16:44 and we have some genuinely exciting space
00:16:44 --> 00:16:46 weather news for our listeners in the
00:16:46 --> 00:16:47 Southern hemisphere tonight.
00:16:47 --> 00:16:50 Avery: A G1 minor geomagnetic
00:16:50 --> 00:16:53 storm struck in the early hours of yesterday
00:16:53 --> 00:16:55 morning, triggered by fast solar wind from a
00:16:55 --> 00:16:58 coronal hole combining with what's called a
00:16:58 --> 00:17:01 UH CO rotating interaction region, or
00:17:01 --> 00:17:03 cir. A, uh, glancing blow from a
00:17:03 --> 00:17:06 coronal mass ejection launched on June 20
00:17:06 --> 00:17:09 may have also contributed. The disturbance
00:17:09 --> 00:17:11 hit the G1 threshold at 4.43in the
00:17:11 --> 00:17:12 morning UTC.
00:17:13 --> 00:17:16 Anna: Now, a UH G1 storm is the lowest level on the
00:17:16 --> 00:17:19 five step geomagnetic scale, but it's enough
00:17:19 --> 00:17:22 to push Auroras to higher mid latitudes.
00:17:22 --> 00:17:24 And here's the headline for tonight and
00:17:24 --> 00:17:27 tomorrow night. More unsettled conditions are
00:17:27 --> 00:17:29 expected with another G1 interval possible
00:17:30 --> 00:17:32 late tonight as, uh, the coronal hol stream
00:17:32 --> 00:17:34 continues to strengthen.
00:17:34 --> 00:17:36 Avery: If the interplanetary magnetic field flips
00:17:36 --> 00:17:39 southward and stays that way for long enough,
00:17:39 --> 00:17:42 aurora watchers in Tasmania, New
00:17:42 --> 00:17:44 Zealand's south island and southern parts of
00:17:44 --> 00:17:47 Victoria and South Australia could be in with
00:17:47 --> 00:17:50 a genuine chance tonight. Winter nights in
00:17:50 --> 00:17:52 the Southern Hemisphere right now are long
00:17:52 --> 00:17:55 and dark perfect conditions if the activity
00:17:55 --> 00:17:55 picks up.
00:17:56 --> 00:17:58 Anna: Northern Hemisphere listeners, the short June
00:17:58 --> 00:18:01 nights are working against you significantly.
00:18:02 --> 00:18:04 If the KP index does hit 5 or above,
00:18:04 --> 00:18:06 you'd need to be at high latitudes in
00:18:06 --> 00:18:09 Scandinavia, Iceland or northern
00:18:09 --> 00:18:11 Scotland to have a realistic chance.
00:18:11 --> 00:18:14 Avery: But there's an even bigger story developing
00:18:14 --> 00:18:17 on the sun itself. A large, complex
00:18:17 --> 00:18:19 new sunspot region designated
00:18:19 --> 00:18:22 AR4478 is
00:18:22 --> 00:18:24 rotating into Earth view over the solar
00:18:24 --> 00:18:27 eastern horizon. It announced its arrival
00:18:27 --> 00:18:30 with a C8.7 class flare,
00:18:30 --> 00:18:32 which was partially blocked by the solar
00:18:32 --> 00:18:35 limb, meaning the actual energy release
00:18:35 --> 00:18:37 was likely considerably more powerful than
00:18:37 --> 00:18:39 the recorded level.
00:18:39 --> 00:18:42 Anna: AR4478 appears to be a
00:18:42 --> 00:18:44 substantial magnetically complex region
00:18:45 --> 00:18:47 first spotted on the Sun's far side by the
00:18:47 --> 00:18:50 Solar Orbiter spacecraft as it rotates
00:18:50 --> 00:18:52 fully onto the Earth facing disk. Over the
00:18:52 --> 00:18:55 next day or two, the chances of M M class
00:18:55 --> 00:18:57 flares moderate, potentially auroral
00:18:58 --> 00:19:00 are expected to increase significantly.
00:19:01 --> 00:19:02 Avery: So keep an eye on space weather updates over
00:19:02 --> 00:19:05 the coming days. This one bears watching.
00:19:05 --> 00:19:08 Check apps like Space Weather Live or Earth
00:19:08 --> 00:19:09 Sky's Sun News page for the latest.
00:19:10 --> 00:19:12 Anna: And on a broader note, we are currently near
00:19:12 --> 00:19:15 solar maximum in the current 11 year solar
00:19:15 --> 00:19:17 cycle, which means heightened solar activity
00:19:17 --> 00:19:20 is the new normal. For the next year or two,
00:19:20 --> 00:19:22 these events will keep coming.
00:19:22 --> 00:19:24 Avery: And that brings us to the end of today's
00:19:24 --> 00:19:27 astronomy Daily Season 5 Episode
00:19:27 --> 00:19:29 125 what a show it's been.
00:19:29 --> 00:19:32 Anna: We covered 60 million stars in a
00:19:32 --> 00:19:35 single Euclid image, a tiny Hubble
00:19:35 --> 00:19:37 galaxy that may have cleared the cosmic fog
00:19:37 --> 00:19:40 of the early universe, the 3 billion year
00:19:40 --> 00:19:43 old Australian crater that is officially the
00:19:43 --> 00:19:46 oldest scar on our planet, two
00:19:46 --> 00:19:49 planet sized cotton candy puffs defying
00:19:49 --> 00:19:52 everything we knew about density, a uh, rogue
00:19:52 --> 00:19:54 SpaceX rocket stage headed for the Moon in
00:19:54 --> 00:19:57 August, and a live solar alert for
00:19:57 --> 00:19:58 aurora hunters in the south.
00:19:59 --> 00:20:01 Avery: Before we go, our ah, did you'd know for
00:20:01 --> 00:20:04 today, The Euclid Space Telescope's
00:20:04 --> 00:20:06 galactic bulge image released this week
00:20:06 --> 00:20:09 includes 51 already known planetary
00:20:09 --> 00:20:12 systems embedded within those 60 million
00:20:12 --> 00:20:15 stars. Every single one of those planets
00:20:15 --> 00:20:18 was discovered by noticing a tiny dimming
00:20:18 --> 00:20:20 of its host star's light, a dimming
00:20:20 --> 00:20:23 equivalent to watching a flea walk across a
00:20:23 --> 00:20:26 car headlight from several kilometers away.
00:20:27 --> 00:20:29 Anna: Thank you so much for spending this time with
00:20:29 --> 00:20:31 us. If you enjoyed today's episode, please
00:20:31 --> 00:20:34 subscribe. Leave us a review on your podcast
00:20:34 --> 00:20:37 platform of choice, and share Astronomy Daily
00:20:37 --> 00:20:39 with someone who looks up at the sky and
00:20:39 --> 00:20:41 wonders. Find us at astronomydaily
00:20:41 --> 00:20:44 IO and follow us on X, Facebook,
00:20:44 --> 00:20:46 Instagram, TikTok and Tumblr
00:20:47 --> 00:20:50 astrodaily Pod until next time from
00:20:50 --> 00:20:52 Avery: both of us, Clear Skies Clear skies.
00:20:53 --> 00:20:54 Astronomy Day
00:20:56 --> 00:20:56 Stories.