Astronomy Daily — S05E147: "Space Mechanic" Wednesday 22 July 2026 A spacecraft with robotic arms is on its way to geostationary orbit to keep other satellites alive. A discarded rocket stage is two weeks out from hitting the Moon, and twenty-three astronomers have just asked the world to watch. Plus the first binary star system where both stars exploded, the first complete magnetic map of a galaxy cluster, and the asteroid breakup that may have bombarded three worlds while Earth froze. In This Episode ● The Space Mechanic Launches — Northrop Grumman's Mission Robotic Vehicle lifted off from Cape Canaveral on 21 July carrying three Mission Extension Pods. With two 3-metre robotic arms built by the US Naval Research Laboratory, it is designed to inspect, relocate, repair and refuel satellites in geostationary orbit. Each pod can give a 2,000 kg satellite up to eight more years of life. ● UPDATE — The Rocket Aimed at the Moon — A new arXiv preprint signed by 23 astronomers calls for a coordinated observing campaign when Falcon 9 upper stage 2025-010D strikes the Moon near Einstein crater on 5 August. North America has the best seat: 2:34am EDT, with the paper naming observers in the Americas as the ideal group. Refined impact time, predicted crater size, and why the ejecta plume may be visible even if the flash is not. ● Sibling Supernovae — Sixteen years of Fermi data reveal a faint supernova remnant hiding in the glare of the Jellyfish Nebula. The two may be the first known pair of remnants traced back to a single binary star system. ● Mapping a Cluster's Magnetic Field — Using the deepest radio observations ever made with LOFAR, astronomers have reconstructed the magnetic field of galaxy cluster Abell 2255 from nucleus to outer edge for the first time. ● The Eulalia Bombardment — A new Planetary Science Journal paper links the breakup of a main-belt asteroid to an impact shower that battered the Moon, Earth and Mars 800 million years ago — and may connect to a global freeze. ● Skywatch, Both Hemispheres — Why this week beats peak night for the Delta Aquariids wherever you are, how to catch them from the southern US and Mediterranean, and what's coming on 12 August: a total solar eclipse across Iceland and Spain, a North American partial, and the best Perseid peak in years on a new Moon.
Sources & Further Reading ● Space.com — SpaceX launches satellite repair drone with 10-foot robotic arms to Earth orbit ● NASASpaceflight.com — Falcon 9 to launch MRV-1 robotic servicing spacecraft for Northrop Grumman ● Northrop Grumman SpaceLogistics — Mission Robotic Vehicle and Mission Extension Pod fact sheets ● Scientific American — A SpaceX rocket is about to crash into the moon; scientists will be watching ● Phys.org — When a SpaceX rocket crashes into the moon, scientists will be watching (arXiv preprint) ● Project Pluto (Bill Gray) — Upper stage impacting the moon on 2026 August 5 ● Stanford University — Researchers uncover evidence for sibling supernovas (Michailidis et al., Nature Communications) ● Reuters — Scientists spot evidence of two huge companion stars that blew up ● Space.com — Galaxy cluster's magnetic field reconstructed for 1st time with record-breaking astronomy map (Botteon et al., INAF, A&A) ● Southwest Research Institute — SwRI-led research connects asteroid collision to impact showers 800 million years ago ● The Planetary Science Journal — Bottke, Vokrouhlický, Dykhuis & Zellner, "An 800 Myr-old Impact Shower on the Terrestrial Planets from the Breakup of the Eulalia Parent Body" ● EarthSky — Delta Aquariid meteor shower: all you need to know in 2026 ● NASA Science — Total Solar Eclipse on August 12, 2026 (path, partial visibility and safety guidance) ● BBC Sky at Night Magazine — August 12, 2026 solar eclipse: USA and Canada guide Connect ● Website: astronomydaily.io (http://astronomydaily.io) ● Socials: @AstroDailyPod ● Part of the Bitesz.com Podcast Network
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00:00:00 --> 00:00:02 Somewhere above your head right now,
00:00:02 --> 00:00:07 about 36 km up, there is a graveyard
00:00:07 --> 00:00:10 shift going on. Hundreds of satellites
00:00:10 --> 00:00:13 still working, still useful, and slowly
00:00:13 --> 00:00:15 running out of fuel.
00:00:15 --> 00:00:17 >> And as of last night, there is finally a
00:00:18 --> 00:00:19 mechanic on the way.
00:00:19 --> 00:00:21 >> Good evening and welcome to Astronomy
00:00:21 --> 00:00:23 Daily. I'm Anna.
00:00:23 --> 00:00:26 >> And I'm Avery. Coming up, a spacecraft
00:00:26 --> 00:00:28 with arms launches on a mission to keep
00:00:28 --> 00:00:31 other spacecraft alive. A rocket stage
00:00:31 --> 00:00:33 is two weeks out from hitting the moon,
00:00:33 --> 00:00:35 and astronomers have just put out a call
00:00:35 --> 00:00:36 to arms about it.
00:00:36 --> 00:00:38 >> We've got two stars that were born
00:00:38 --> 00:00:41 together, lived together, and then died
00:00:41 --> 00:00:44 in sequence, leaving behind the first
00:00:44 --> 00:00:47 pair of supernova remnants ever traced
00:00:47 --> 00:00:50 back to a single binary. the first
00:00:50 --> 00:00:52 complete magnetic map of a galaxy
00:00:52 --> 00:00:54 cluster, an asteroid breakup that may
00:00:54 --> 00:00:56 have bombarded three worlds and helped
00:00:56 --> 00:00:58 freeze our own,
00:00:58 --> 00:01:00 >> and a skywatching window that is closing
00:01:00 --> 00:01:02 faster than you'd like.
00:01:02 --> 00:01:04 >> Let's get into it.
00:01:04 --> 00:01:06 >> So, Avery, here's a problem that has
00:01:06 --> 00:01:08 quietly bothered the satellite industry
00:01:08 --> 00:01:11 for about 60 years. You build a
00:01:11 --> 00:01:13 satellite. You spend hundreds of
00:01:14 --> 00:01:16 millions of dollars on it. You put it in
00:01:16 --> 00:01:20 geostationary orbit 35
00:01:20 --> 00:01:23 km up where it hovers over the same
00:01:23 --> 00:01:26 patch of ground forever and it works
00:01:26 --> 00:01:29 beautifully for 15 years and then it
00:01:29 --> 00:01:31 runs out of fuel
00:01:31 --> 00:01:33 >> and that's it. The hardware is fine.
00:01:33 --> 00:01:36 >> The hardware is often perfectly fine.
00:01:36 --> 00:01:38 The cameras work, the transponders work,
00:01:38 --> 00:01:41 the solar panels work, but without
00:01:41 --> 00:01:43 propellant, it can't hold its position.
00:01:43 --> 00:01:46 So, it drifts and it becomes junk. You
00:01:46 --> 00:01:49 throw away a working satellite because
00:01:49 --> 00:01:51 the tank is empty.
00:01:51 --> 00:01:53 >> That is a spectacularly wasteful way to
00:01:53 --> 00:01:54 run an industry.
00:01:54 --> 00:01:57 >> It is. And last night, Northre Grumman
00:01:57 --> 00:02:00 launched the most serious attempt yet to
00:02:00 --> 00:02:03 fix it. At 5:15 in the evening, Eastern
00:02:03 --> 00:02:07 time on Tuesday the 21st of July, the
00:02:07 --> 00:02:09 Falcon 9 lifted off from Space Launch
00:02:10 --> 00:02:13 Complex 40 at Cape Canaveral carrying
00:02:13 --> 00:02:15 the mission robotic vehicle plus three
00:02:16 --> 00:02:18 mission extension pods.
00:02:18 --> 00:02:20 >> Mission robotic vehicle. What does it
00:02:20 --> 00:02:23 actually look like? Picture a satellite
00:02:23 --> 00:02:26 bus with two arms, two robotic arms,
00:02:26 --> 00:02:30 each about 3 m long, 10 ft, built by the
00:02:30 --> 00:02:33 United States Naval Research Laboratory
00:02:33 --> 00:02:36 and supplied through DARPA's robotic
00:02:36 --> 00:02:38 servicing of geostationary satellite
00:02:38 --> 00:02:39 program.
00:02:39 --> 00:02:42 >> So this is a genuinely dextrous machine,
00:02:42 --> 00:02:44 not just the tug that bolts on.
00:02:44 --> 00:02:46 >> That's the distinction that matters. The
00:02:46 --> 00:02:50 MRV can inspect, it can relocate, it can
00:02:50 --> 00:02:53 repair, it can upgrade, and its headline
00:02:53 --> 00:02:56 job on this mission is to pick up those
00:02:56 --> 00:02:58 three mission extension pods and install
00:02:58 --> 00:03:00 them on client satellites that are
00:03:00 --> 00:03:02 running low on propellant.
00:03:02 --> 00:03:05 >> So, the pods are the actual fuel
00:03:05 --> 00:03:06 solution.
00:03:06 --> 00:03:09 >> Think of them as jetpacks. Each pod
00:03:09 --> 00:03:11 clamps onto a satellite and takes over
00:03:11 --> 00:03:13 orbit control and momentum management
00:03:13 --> 00:03:16 using electric propulsion. Each one can
00:03:16 --> 00:03:20 handle a satellite of about 2 kg.
00:03:20 --> 00:03:23 That's a typical big geostationary bird.
00:03:23 --> 00:03:26 And give it up to 8 more years of life.
00:03:26 --> 00:03:28 >> 8 years on a satellite that was
00:03:28 --> 00:03:30 otherwise finished.
00:03:30 --> 00:03:33 >> 8 years. And the MRV itself carries
00:03:34 --> 00:03:36 something called a passive refueling
00:03:36 --> 00:03:38 interface, which is the first refueling
00:03:38 --> 00:03:41 interface approved by the US Space
00:03:41 --> 00:03:43 Force. So, the servicer is itself
00:03:43 --> 00:03:46 designed to be refueled later.
00:03:46 --> 00:03:48 >> Now, Northrub have done a version of
00:03:48 --> 00:03:49 this before, haven't they?
00:03:49 --> 00:03:52 >> They have, and this is why they're the
00:03:52 --> 00:03:55 ones doing it. Bish extension vehicle 1
00:03:55 --> 00:03:58 launched in October 2019. The first
00:03:58 --> 00:04:00 commercial satellite servicing
00:04:00 --> 00:04:03 spacecraft ever. And 4 months later, it
00:04:03 --> 00:04:05 docked with communication satellite
00:04:05 --> 00:04:09 Intelsat 901 in geostationary orbit.
00:04:09 --> 00:04:13 MEV2 followed in August 2020.
00:04:13 --> 00:04:14 >> So what's different this time?
00:04:14 --> 00:04:17 >> Those earlier vehicles were one to one.
00:04:17 --> 00:04:20 One serer went to one satellite, docked
00:04:20 --> 00:04:22 with it, and stayed there doing the work
00:04:22 --> 00:04:26 itself. The MRV is one to many. It
00:04:26 --> 00:04:29 carries pods, installs them, and moves
00:04:29 --> 00:04:31 on. It's the difference between a tow
00:04:31 --> 00:04:33 truck that has to stay attached to your
00:04:33 --> 00:04:36 car forever and a mechanic who fits a
00:04:36 --> 00:04:39 new part and drives off to the next job.
00:04:39 --> 00:04:40 That scales.
00:04:40 --> 00:04:43 >> That scales. And there's a nice detail
00:04:43 --> 00:04:45 on the launch itself. The Falcon 9
00:04:46 --> 00:04:48 booster B1069
00:04:48 --> 00:04:51 was flying its 302nd mission and it was
00:04:51 --> 00:04:54 deliberately expended. No landing.
00:04:54 --> 00:04:56 >> Why give up a booster with 31 flights on
00:04:56 --> 00:04:59 it? Because GEO's stationary transfer
00:04:59 --> 00:05:01 orbit is demanding. Getting that much
00:05:01 --> 00:05:04 mass that high needed every bit of
00:05:04 --> 00:05:06 performance the rocket had. And there
00:05:06 --> 00:05:08 wasn't propellant left for a landing
00:05:08 --> 00:05:11 burn. SpaceX made the trade.
00:05:11 --> 00:05:13 >> So when does the actual servicing start?
00:05:13 --> 00:05:16 >> Not for a while. The MRV and the three
00:05:16 --> 00:05:18 pods each separate and then climb to
00:05:18 --> 00:05:21 geostationary orbit under their own
00:05:21 --> 00:05:23 solar electric propulsion. And that
00:05:24 --> 00:05:26 climb takes up to a year. Servicing
00:05:26 --> 00:05:28 operations are expected to begin in
00:05:28 --> 00:05:32 2027. After the initial checkouts, the
00:05:32 --> 00:05:35 RSGS program gets handed over to the US
00:05:35 --> 00:05:36 Space Force.
00:05:36 --> 00:05:38 >> A year of just going up
00:05:38 --> 00:05:41 >> slowly and efficiently. Electric
00:05:41 --> 00:05:43 propulsion is patient. And at the end of
00:05:43 --> 00:05:46 it, for the first time, there's a repair
00:05:46 --> 00:05:48 capability parked permanently in the
00:05:48 --> 00:05:51 most valuable orbital real estate we
00:05:51 --> 00:05:51 have.
00:05:51 --> 00:05:54 >> Right. From a machine built to preserve
00:05:54 --> 00:05:56 spacecraft to a spacecraft that is about
00:05:56 --> 00:05:58 to be very thoroughly destroyed.
00:05:58 --> 00:06:00 >> This is one we've been tracking.
00:06:00 --> 00:06:02 >> It is. And I want to be upfront about
00:06:02 --> 00:06:05 that. We covered this back in June in
00:06:05 --> 00:06:08 episode 125. But there is a genuine
00:06:08 --> 00:06:10 reason to come back to it because the
00:06:10 --> 00:06:11 science community has just done
00:06:11 --> 00:06:13 something about it. The short version
00:06:13 --> 00:06:17 for anyone joining us since in January
00:06:17 --> 00:06:20 2025, a Falcon 9 launched two commercial
00:06:20 --> 00:06:24 lunar landers, Fireflyy's Blue Ghost and
00:06:24 --> 00:06:28 iSpace's Hakuto R Mission 2. It did its
00:06:28 --> 00:06:31 job, but the upper stage cataloged as
00:06:31 --> 00:06:34 202510D
00:06:34 --> 00:06:37 never came home. Instead of burning up
00:06:37 --> 00:06:40 in our atmosphere, it ended up in a long
00:06:40 --> 00:06:42 looping orbit through the Earth Moon
00:06:42 --> 00:06:44 system. And somebody noticed.
00:06:44 --> 00:06:47 >> The independent astronomer Bill Gray,
00:06:47 --> 00:06:49 who runs Project Pluto and tracks this
00:06:49 --> 00:06:52 sort of high orbit debris, his software
00:06:52 --> 00:06:55 flagged an impact. On the 5th of August
00:06:55 --> 00:06:58 this year, that stage hits the moon.
00:06:58 --> 00:07:01 >> So, what's new? Three things. First, a
00:07:01 --> 00:07:03 new preprint has just gone up on archive
00:07:03 --> 00:07:06 and it is signed by 23 astronomers. It
00:07:06 --> 00:07:09 is essentially a call to arms. They're
00:07:09 --> 00:07:11 asking the scientific community,
00:07:11 --> 00:07:14 professional and amateur, to point
00:07:14 --> 00:07:15 everything they've got at the moon on
00:07:16 --> 00:07:17 the 5th of August
00:07:17 --> 00:07:19 >> because this is a rare thing
00:07:19 --> 00:07:22 >> because we almost never get this. We get
00:07:22 --> 00:07:23 natural impacts on the moon all the
00:07:23 --> 00:07:25 time, but we don't know when they're
00:07:25 --> 00:07:28 coming. Here, we know the object. We
00:07:28 --> 00:07:31 know its mass. We know its structure. We
00:07:31 --> 00:07:33 know its velocity. And we know the time
00:07:33 --> 00:07:35 to within about a second. That is an
00:07:35 --> 00:07:38 artificial impact experiment we didn't
00:07:38 --> 00:07:39 have to pay to set up.
00:07:39 --> 00:07:41 >> And the timing has been tightened,
00:07:41 --> 00:07:42 hasn't it?
00:07:42 --> 00:07:44 >> That's a second. You think Gray's latest
00:07:44 --> 00:07:47 published calculation dated the 17th of
00:07:47 --> 00:07:51 July puts the impact at 634 and 32
00:07:51 --> 00:07:53 seconds UTC. Earlier coverage back in
00:07:53 --> 00:07:57 May was quoting 644. So, if you've got
00:07:57 --> 00:07:59 the old number written down, update it.
00:07:59 --> 00:08:00 >> And the third,
00:08:00 --> 00:08:02 >> the third is the actual physics
00:08:02 --> 00:08:05 prediction. And this is the part I find
00:08:05 --> 00:08:07 genuinely interesting. The paper models
00:08:07 --> 00:08:10 what happens on contact. This thing is
00:08:10 --> 00:08:14 roughly 12 m long and about 4 kg.
00:08:14 --> 00:08:17 And crucially, it's hollow. It's a tank.
00:08:17 --> 00:08:19 So, the prediction is that it crushes
00:08:19 --> 00:08:21 rather than punching deep.
00:08:21 --> 00:08:24 >> Like a can rather than a bullet.
00:08:24 --> 00:08:26 >> Exactly like a can. And the result of
00:08:26 --> 00:08:29 that is a relatively shallow crater.
00:08:29 --> 00:08:31 They're estimating 20 to 30 meters
00:08:31 --> 00:08:35 across, but a very large eject plume.
00:08:35 --> 00:08:37 Kilometers of debris thrown up off the
00:08:37 --> 00:08:38 surface.
00:08:38 --> 00:08:40 >> So, the plume might be the visible part.
00:08:40 --> 00:08:42 >> That's the hope. And it's a subtle bit
00:08:42 --> 00:08:45 of reasoning. The impact site is near
00:08:45 --> 00:08:47 the crater Einstein, right on the moon's
00:08:47 --> 00:08:49 western limb, about the 10:00 position
00:08:50 --> 00:08:52 on the disc as you look at it. Now,
00:08:52 --> 00:08:54 that's awkward because it's on the
00:08:54 --> 00:08:56 sunlit part of the surface and no impact
00:08:56 --> 00:08:59 flash, artificial or natural, has ever
00:08:59 --> 00:09:01 been recorded on the lit face of the
00:09:01 --> 00:09:03 moon. The glare defeats you,
00:09:04 --> 00:09:06 >> but being on the limb helps.
00:09:06 --> 00:09:08 >> Being on the limb might save it because
00:09:08 --> 00:09:10 rocks thrown up from a site that close
00:09:10 --> 00:09:13 to the edge rise off the moon entirely.
00:09:13 --> 00:09:15 And once they're off the limb, they're
00:09:15 --> 00:09:17 silhouetted against black sky catching
00:09:17 --> 00:09:19 sunlight. So you might not see the
00:09:19 --> 00:09:21 flash, but you might see the plume.
00:09:21 --> 00:09:23 >> Who else is watching?
00:09:23 --> 00:09:25 >> NASA's Lunar Reconnaissance Orbiter will
00:09:25 --> 00:09:28 image the site before and after, which
00:09:28 --> 00:09:30 gives a clean comparison. And South
00:09:30 --> 00:09:32 Korea's Pathfinder Lunar Orbiter is
00:09:32 --> 00:09:34 going to attempt to observe as well.
00:09:34 --> 00:09:36 There's precedent for the after image,
00:09:36 --> 00:09:38 too. When a Chinese rocket stage hit the
00:09:38 --> 00:09:41 far side in 2022, LRO found the site,
00:09:41 --> 00:09:44 and it had made not one crater, but two.
00:09:44 --> 00:09:46 >> And there's a longer term payoff to all
00:09:46 --> 00:09:49 this. And this is why the paper matters
00:09:49 --> 00:09:51 beyond the spectacle. They want to test
00:09:51 --> 00:09:54 a method for pinpointing exactly where
00:09:54 --> 00:09:56 an object strikes the moon using the
00:09:56 --> 00:09:58 observations. If you can nail that down
00:09:58 --> 00:10:01 against a known impact, you validated a
00:10:01 --> 00:10:03 technique and that feeds directly into
00:10:03 --> 00:10:05 planning seismic experiments on the
00:10:05 --> 00:10:07 lunar surface for future missions.
00:10:07 --> 00:10:10 >> Now, the practical question, who
00:10:10 --> 00:10:12 actually gets to see this? And this is
00:10:12 --> 00:10:14 where our North American listeners want
00:10:14 --> 00:10:16 to pay attention because this one is
00:10:16 --> 00:10:20 squarely yours. 6:34 UTC on the 5th of
00:10:20 --> 00:10:23 August is 29 minutes past 2:00 in the
00:10:23 --> 00:10:26 morning Eastern time, 1:34 central,
00:10:26 --> 00:10:29 12:34 Mountain, and on the West Coast,
00:10:29 --> 00:10:31 it's still the night before, 11:34 in
00:10:31 --> 00:10:33 the evening on the 4th.
00:10:33 --> 00:10:35 >> Middle of the night, but the moon is
00:10:35 --> 00:10:37 well up. The moon is wellplaced across
00:10:37 --> 00:10:40 the continent and the paper specifically
00:10:40 --> 00:10:42 identifies observers in the Americas as
00:10:42 --> 00:10:45 the ideal group. If you have a telescope
00:10:45 --> 00:10:47 and you've ever wanted to contribute to
00:10:47 --> 00:10:49 something real, this is the night. They
00:10:49 --> 00:10:52 are explicitly asking amateurs to take
00:10:52 --> 00:10:52 part.
00:10:52 --> 00:10:54 >> And for those of us further around the
00:10:54 --> 00:10:55 globe,
00:10:55 --> 00:10:57 >> less kind, and I'll be straight about
00:10:57 --> 00:11:00 it. For us in Australia, that's 4:34 in
00:11:00 --> 00:11:02 the afternoon. Broad daylight. New
00:11:02 --> 00:11:05 Zealand, early evening, no good either.
00:11:05 --> 00:11:08 The UK and Europe get half 7 in the
00:11:08 --> 00:11:10 morning which is also daylight. So the
00:11:10 --> 00:11:13 live event belongs to the Americas.
00:11:13 --> 00:11:15 >> But the aftermath belongs to everyone.
00:11:15 --> 00:11:17 >> The aftermath belongs to everyone. The
00:11:18 --> 00:11:20 LRO before and after imagery, the crater
00:11:20 --> 00:11:23 measurements, the analysis of how well
00:11:23 --> 00:11:25 the predictions held up. And frankly,
00:11:25 --> 00:11:27 the question sitting underneath all of
00:11:27 --> 00:11:29 this is global. We are about to start
00:11:29 --> 00:11:31 putting people back on the moon. and we
00:11:31 --> 00:11:33 are currently hitting it with our own
00:11:33 --> 00:11:36 rubbish by accident without warning.
00:11:36 --> 00:11:38 >> All right, Avery, moving on to our next
00:11:38 --> 00:11:41 story. More than half of all stars are
00:11:41 --> 00:11:44 in multiple systems, two or more suns
00:11:44 --> 00:11:47 orbiting each other. And for the really
00:11:47 --> 00:11:49 massive stars, the ones destined to
00:11:49 --> 00:11:52 explode, that fraction is even higher.
00:11:52 --> 00:11:54 >> So most supernovas should have had a
00:11:54 --> 00:11:55 sibling.
00:11:55 --> 00:11:58 >> That is exactly the implication. And yet
00:11:58 --> 00:12:01 until this week, astronomers had never
00:12:01 --> 00:12:03 found a single case where both stars in
00:12:03 --> 00:12:06 a binary exploded and both left behind
00:12:06 --> 00:12:08 remnants we can still see.
00:12:08 --> 00:12:10 >> Not one out of how many?
00:12:10 --> 00:12:13 >> We've cataloged around 300 supernova
00:12:13 --> 00:12:15 remnants in our galaxy. Not one
00:12:15 --> 00:12:17 confirmed sibling pair. And the reason
00:12:17 --> 00:12:19 is a bit embarrassing actually. One of
00:12:20 --> 00:12:22 them was probably sitting in plain sight
00:12:22 --> 00:12:23 the whole time.
00:12:23 --> 00:12:28 >> Go on. The Jellyfish Nebula IC 443 in
00:12:28 --> 00:12:31 the constellation Gemini about 6
00:12:31 --> 00:12:33 lighty years away. It is one of the best
00:12:33 --> 00:12:36 studied supernova remnants in the sky
00:12:36 --> 00:12:38 and one of the brightest gamma ray
00:12:38 --> 00:12:40 sources of its kind. If you could see it
00:12:40 --> 00:12:42 with your eye, it would look bigger than
00:12:42 --> 00:12:44 the full moon.
00:12:44 --> 00:12:46 >> And something was hiding behind it.
00:12:46 --> 00:12:49 >> Next to it, there's a much fainter
00:12:49 --> 00:12:52 object called G189.6
00:12:52 --> 00:12:55 + 3. It was first picked up in 1994 by
00:12:55 --> 00:12:58 the German ROSAT satellite as a faint
00:12:58 --> 00:13:01 X-ray glow and later the Russian German
00:13:01 --> 00:13:04 Spectrum Ronkin Gamma Observatory saw
00:13:04 --> 00:13:06 shell-like structures in it which
00:13:06 --> 00:13:08 suggested it was also a supernova
00:13:08 --> 00:13:11 remnant but it sits right up against the
00:13:11 --> 00:13:14 glare of the jellyfish and that glare
00:13:14 --> 00:13:15 drowns it.
00:13:15 --> 00:13:18 >> So how did they finally separate them?
00:13:18 --> 00:13:21 16 years of data from NASA's Fermy Gamma
00:13:21 --> 00:13:24 Ray Space Telescope. The team led by
00:13:24 --> 00:13:27 Miltiadis Malites, a post-doal fellow at
00:13:27 --> 00:13:30 Stanford, essentially subtracted the
00:13:30 --> 00:13:32 jellyfish out, isolated its gammaray
00:13:32 --> 00:13:34 emission, and looked at what was left
00:13:34 --> 00:13:35 underneath.
00:13:35 --> 00:13:37 >> And there was something left.
00:13:37 --> 00:13:40 >> There was G189.6
00:13:40 --> 00:13:43 6 + 3 is independently producing gamma
00:13:43 --> 00:13:46 rays which matters enormously because
00:13:46 --> 00:13:48 gamma rays mean particle acceleration
00:13:48 --> 00:13:50 and particle acceleration is what a
00:13:50 --> 00:13:53 supernova remnant does. It's the shock
00:13:53 --> 00:13:54 wave doing work.
00:13:54 --> 00:13:57 >> Ma's had a nice way of putting that,
00:13:57 --> 00:13:57 didn't he?
00:13:57 --> 00:14:00 >> He compared it to a drop of water
00:14:00 --> 00:14:02 falling on a still lake. The ripples
00:14:02 --> 00:14:05 spread out from the point of contact. A
00:14:05 --> 00:14:07 supernova remnant does exactly the same
00:14:07 --> 00:14:09 thing. And if you can see the ripples,
00:14:09 --> 00:14:11 you know something dropped.
00:14:11 --> 00:14:14 >> So, we have two remnants next to each
00:14:14 --> 00:14:16 other. How do we know they're related
00:14:16 --> 00:14:17 rather than just an accident of line of
00:14:18 --> 00:14:18 sight?
00:14:18 --> 00:14:20 >> This is the elegant part. There's a
00:14:20 --> 00:14:23 filament of gas arcing between them. And
00:14:23 --> 00:14:25 that filament is where the shock wave
00:14:25 --> 00:14:27 from G189.6
00:14:27 --> 00:14:30 + 3 has slammed into the same molecular
00:14:30 --> 00:14:33 cloud that the jellyfish is pushing
00:14:33 --> 00:14:33 against.
00:14:34 --> 00:14:36 >> Same cloud. So, same distance.
00:14:36 --> 00:14:38 >> Same cloud. same distance, same
00:14:38 --> 00:14:41 neighborhood. They're not one in front
00:14:41 --> 00:14:43 of the other. They're genuinely next
00:14:43 --> 00:14:45 door to each other. And that's what
00:14:45 --> 00:14:48 makes the shared origin story credible.
00:14:48 --> 00:14:49 >> So, walk me through the story they're
00:14:49 --> 00:14:50 proposing.
00:14:50 --> 00:14:53 >> A tale of two massive stars born
00:14:53 --> 00:14:55 together, gravitationally bound,
00:14:55 --> 00:14:59 orbiting extremely closely, perhaps only
00:14:59 --> 00:15:01 a few times the Earth's sun distance
00:15:01 --> 00:15:04 apart. Close enough that material was
00:15:04 --> 00:15:06 likely flowing from one to the other.
00:15:06 --> 00:15:08 And then the bigger one runs out of fuel
00:15:08 --> 00:15:10 and detonates.
00:15:10 --> 00:15:11 >> And the explosion breaks the
00:15:12 --> 00:15:12 partnership.
00:15:12 --> 00:15:15 >> The explosion breaks the partnership.
00:15:15 --> 00:15:17 The binary is disrupted and the
00:15:17 --> 00:15:19 surviving companion is essentially
00:15:19 --> 00:15:22 kicked, flung off through the galaxy on
00:15:22 --> 00:15:25 its own. It keeps traveling and tens of
00:15:25 --> 00:15:27 thousands of years later, it explodes,
00:15:27 --> 00:15:28 too.
00:15:28 --> 00:15:30 >> How far apart did they end up? The
00:15:30 --> 00:15:33 centers of the two explosions are now
00:15:33 --> 00:15:35 somewhere between 30 and 50 light years
00:15:35 --> 00:15:38 apart. Two stars that were once close
00:15:38 --> 00:15:40 enough to be exchanging material now
00:15:40 --> 00:15:43 separated by that gap and each marked by
00:15:43 --> 00:15:45 its own expanding shell.
00:15:45 --> 00:15:46 >> What were they?
00:15:46 --> 00:15:49 >> The jellyfish's progenitor is thought to
00:15:49 --> 00:15:52 have been something like 15 to 25 times
00:15:52 --> 00:15:55 the mass of the sun. Its companion at
00:15:55 --> 00:15:58 least 20. both were probably tens of
00:15:58 --> 00:16:00 thousands times more luminous than the
00:16:00 --> 00:16:03 sun and both may now be neutron stars
00:16:03 --> 00:16:05 >> and publication status because I know
00:16:05 --> 00:16:07 this was previewed at a conference.
00:16:07 --> 00:16:10 >> Good flag. Milti presented the results
00:16:10 --> 00:16:12 at the American Astronomical Society
00:16:12 --> 00:16:15 meeting in Pasadena back in June. What's
00:16:15 --> 00:16:17 happened this week is the peer-reviewed
00:16:17 --> 00:16:19 paper. It's in Nature Communications
00:16:19 --> 00:16:21 with the Stanford release and wider
00:16:21 --> 00:16:24 coverage landing on the 21st.
00:16:24 --> 00:16:26 >> And one for our listeners. Can we go and
00:16:26 --> 00:16:27 look at any of this?
00:16:27 --> 00:16:30 >> Not this month, wherever you are. Gemini
00:16:30 --> 00:16:32 is close to the sun at the moment, so
00:16:32 --> 00:16:35 it's lost in the glare globally, but it
00:16:35 --> 00:16:37 comes back. And this is one where our
00:16:37 --> 00:16:39 northern hemisphere listeners get the
00:16:39 --> 00:16:41 better deal. From North America and
00:16:42 --> 00:16:44 Europe, Gemini rides high overhead
00:16:44 --> 00:16:47 through winter, December into March, and
00:16:47 --> 00:16:49 the jellyfish sits beautifully placed
00:16:49 --> 00:16:53 for a telescope or a long exposure. And
00:16:53 --> 00:16:54 from down here,
00:16:54 --> 00:16:56 >> we still get it just lower. From
00:16:56 --> 00:16:58 Australia and New Zealand, Gemini comes
00:16:58 --> 00:17:00 up in the northern sky through our
00:17:00 --> 00:17:03 summer. Visible, worth hunting, but
00:17:03 --> 00:17:06 closer to the horizon. Either way, put
00:17:06 --> 00:17:07 it on the list for the end of the year.
00:17:07 --> 00:17:09 And bear in mind, the jellyfish is
00:17:10 --> 00:17:12 faint. It would be bigger than the full
00:17:12 --> 00:17:14 moon if your eye could pick it up, but
00:17:14 --> 00:17:16 it needs photography or a decent
00:17:16 --> 00:17:18 aperture to show itself. Anna, here's
00:17:18 --> 00:17:20 something we know exists, but have never
00:17:20 --> 00:17:23 actually been able to draw. Galaxy
00:17:23 --> 00:17:25 clusters. The largest gravitationally
00:17:26 --> 00:17:28 bound structures in the universe.
00:17:28 --> 00:17:30 Hundreds or thousands of galaxies plus
00:17:30 --> 00:17:33 enormous clouds of hot gas plus dark
00:17:33 --> 00:17:35 matter are threaded through with
00:17:35 --> 00:17:37 magnetic fields.
00:17:37 --> 00:17:39 >> We've known that for decades.
00:17:39 --> 00:17:41 >> What we have never done is map the shape
00:17:41 --> 00:17:44 of one across an entire cluster from the
00:17:44 --> 00:17:47 middle right out to the edge. And now
00:17:47 --> 00:17:48 somebody has
00:17:48 --> 00:17:51 >> a team led by Andrea Bhuton at INAF,
00:17:51 --> 00:17:53 Italy's National Astrophysics Institute
00:17:53 --> 00:17:55 has reconstructed the magnetic field of
00:17:56 --> 00:17:59 galaxy cluster Abel 2255. And I want to
00:17:59 --> 00:18:01 be precise about that name because at
00:18:01 --> 00:18:03 least one outlet has got it wrong this
00:18:03 --> 00:18:08 week and called it Abel 2142. It is Abel
00:18:08 --> 00:18:09
00:18:09 --> 00:18:11 about a billion lighty years away.
00:18:11 --> 00:18:13 >> Why that cluster?
00:18:13 --> 00:18:15 >> Because it's famously messy in radio.
00:18:16 --> 00:18:19 Abel 2255 has long been known for its
00:18:19 --> 00:18:21 complexity. It's full of strange
00:18:21 --> 00:18:23 diffused radio structures, halos, and
00:18:23 --> 00:18:25 filaments, which is exactly what you
00:18:25 --> 00:18:27 want if you're trying to trace magnetic
00:18:27 --> 00:18:29 fields because those structures are made
00:18:29 --> 00:18:32 by energetic electrons spiraling along
00:18:32 --> 00:18:33 magnetic lines.
00:18:33 --> 00:18:35 >> So the radio emission is the field
00:18:35 --> 00:18:37 effectively made visible.
00:18:37 --> 00:18:40 >> It's the tracer. Electrons corkcrewing
00:18:40 --> 00:18:42 along magnetic lines give off radio
00:18:42 --> 00:18:44 waves. So if you can see the emission
00:18:44 --> 00:18:47 finely enough, you can work backwards to
00:18:47 --> 00:18:49 the field. The problem has always been
00:18:49 --> 00:18:51 that these signals are extraordinarily
00:18:51 --> 00:18:52 faint.
00:18:52 --> 00:18:54 >> What did they observe with?
00:18:54 --> 00:18:56 >> Loar, the low frequency array, the
00:18:56 --> 00:18:58 European radio telescope, spread across
00:18:58 --> 00:19:01 a continent. And these are the deepest
00:19:01 --> 00:19:03 radio observations ever made of a galaxy
00:19:04 --> 00:19:06 cluster. That was combined with a new
00:19:06 --> 00:19:08 data analysis technique. And between
00:19:08 --> 00:19:09 them, that's what cracked it.
00:19:09 --> 00:19:12 >> And what does the map show? This is
00:19:12 --> 00:19:14 defining. In some regions of the
00:19:14 --> 00:19:16 cluster, the magnetic field lines are
00:19:16 --> 00:19:19 strikingly coherent. They follow very
00:19:19 --> 00:19:21 specific directions, stretching radially
00:19:21 --> 00:19:23 outward along the extended radial
00:19:23 --> 00:19:25 structures. They're not random,
00:19:25 --> 00:19:27 >> which tells you something made them that
00:19:27 --> 00:19:28 way,
00:19:28 --> 00:19:30 >> which tells you something is organizing
00:19:30 --> 00:19:32 them. And Bolton's conclusion is that
00:19:32 --> 00:19:34 the shape of the field is intimately
00:19:34 --> 00:19:36 linked to the motion of the gas it sits
00:19:36 --> 00:19:39 in. The field gets stretched and
00:19:39 --> 00:19:41 compressed by the movements associated
00:19:41 --> 00:19:43 with the cluster's own formation.
00:19:43 --> 00:19:45 >> So the cluster assembling itself is what
00:19:45 --> 00:19:47 shapes the magnetism.
00:19:47 --> 00:19:49 >> That's the argument and it's the first
00:19:49 --> 00:19:51 observational evidence of it. The same
00:19:51 --> 00:19:53 violent process that builds a galaxy
00:19:53 --> 00:19:57 cluster. Gas falling in, sloshing,
00:19:57 --> 00:19:59 colliding, merging is the process that
00:19:59 --> 00:20:01 combs the magnetic field into the
00:20:01 --> 00:20:03 pattern we now see.
00:20:03 --> 00:20:05 >> And that ties into the radio halos
00:20:05 --> 00:20:08 question. It does. Bolton says they
00:20:08 --> 00:20:10 believe the mechanism that switches on
00:20:10 --> 00:20:12 these gigantic radio emissions is linked
00:20:12 --> 00:20:14 to the formation process of the clusters
00:20:14 --> 00:20:17 themselves. So, the map isn't just a
00:20:17 --> 00:20:19 pretty picture. It's the evidence for
00:20:19 --> 00:20:20 the engine.
00:20:20 --> 00:20:22 >> It's a lovely example of the thing
00:20:22 --> 00:20:24 radioastronomy does best.
00:20:24 --> 00:20:26 >> Showing you a structure that is
00:20:26 --> 00:20:28 completely invisible, is a billion
00:20:28 --> 00:20:30 lighty years away, is bigger than
00:20:30 --> 00:20:32 anything else in the universe, and has
00:20:32 --> 00:20:34 been sitting there the entire time.
00:20:34 --> 00:20:37 published in astronomy and astrophysics.
00:20:37 --> 00:20:40 >> Every if you want to know what has hit
00:20:40 --> 00:20:42 the earth, don't look at the earth
00:20:42 --> 00:20:44 >> because the earth keeps erasing it
00:20:44 --> 00:20:47 >> constantly. Play tectonics, volcanism,
00:20:47 --> 00:20:50 weather, water, erosion, craters get
00:20:50 --> 00:20:53 buried, distorted, subducted, destroyed.
00:20:53 --> 00:20:55 The practical consequence is that
00:20:55 --> 00:20:57 geological evidence for impacts older
00:20:57 --> 00:21:00 than about 650 million years is
00:21:00 --> 00:21:02 extremely scarce here.
00:21:02 --> 00:21:04 >> And the moon doesn't do any of that. No
00:21:04 --> 00:21:07 plate tectonics, no flowing water, no
00:21:07 --> 00:21:09 meaningful atmosphere. The moon just
00:21:09 --> 00:21:11 keeps the receipts. And when you read
00:21:11 --> 00:21:13 those receipts carefully, there's a
00:21:13 --> 00:21:14 spike
00:21:14 --> 00:21:14 >> when
00:21:14 --> 00:21:17 >> around 800 million years ago, there's a
00:21:17 --> 00:21:19 surge in large lunar impacts, and it
00:21:19 --> 00:21:22 shows up in two independent ways. One is
00:21:22 --> 00:21:25 the estimated ages of big craters,
00:21:25 --> 00:21:28 including Capernicus, which is 93 km
00:21:28 --> 00:21:31 across. The other is impact glass.
00:21:31 --> 00:21:33 Explain impact glass.
00:21:33 --> 00:21:35 >> When something hits hard enough, the
00:21:35 --> 00:21:38 heat melts rock. That melt cools into
00:21:38 --> 00:21:41 glass and the glass locks in a chemical
00:21:41 --> 00:21:43 time stamp. The Apollo missions brought
00:21:43 --> 00:21:45 a lot of it home. And when you look at
00:21:45 --> 00:21:48 the age distribution of that glass, you
00:21:48 --> 00:21:51 see the same spike at 800 million years.
00:21:51 --> 00:21:53 >> So, two different methods agree that
00:21:53 --> 00:21:55 something happened, but nobody knew
00:21:55 --> 00:21:56 what.
00:21:56 --> 00:21:58 >> Nobody knew what. That's the puzzle
00:21:58 --> 00:22:00 that's been sitting there for decades.
00:22:00 --> 00:22:02 And a new paper led by Dr. William Bachi
00:22:02 --> 00:22:04 at the Southwest Research Institute in
00:22:04 --> 00:22:07 Boulder proposes a specific culprit,
00:22:07 --> 00:22:08 >> which is
00:22:08 --> 00:22:11 >> an asteroid called Ulia, or rather the
00:22:11 --> 00:22:13 parent body of the family of asteroids
00:22:13 --> 00:22:16 we now call Ulia because the object
00:22:16 --> 00:22:18 itself no longer exists. It was
00:22:18 --> 00:22:21 catastrophically broken apart in a
00:22:21 --> 00:22:22 collision in the main belt.
00:22:22 --> 00:22:24 >> And the location of that breakup
00:22:24 --> 00:22:25 matters.
00:22:25 --> 00:22:27 >> The location is everything. It happened
00:22:27 --> 00:22:30 right next to what's called the J3:1
00:22:30 --> 00:22:32 resonance with Jupiter. And a resonance
00:22:32 --> 00:22:34 like that is essentially a gravitational
00:22:34 --> 00:22:37 trap door. Material that wanders into it
00:22:37 --> 00:22:39 gets its orbit pumped up by Jupiter and
00:22:39 --> 00:22:42 flung into the inner solar system.
00:22:42 --> 00:22:44 >> So the shrapnel had a delivery mechanism
00:22:44 --> 00:22:45 waiting right there.
00:22:45 --> 00:22:48 >> It had an open door right next to it.
00:22:48 --> 00:22:50 And the simulations show what happened
00:22:50 --> 00:22:52 in two phases. Half the fragments
00:22:52 --> 00:22:53 reached the resonance almost
00:22:53 --> 00:22:55 immediately. That's the prompt
00:22:55 --> 00:22:58 bombardment. planetary shrapnel sprayed
00:22:58 --> 00:22:59 across the inner solar system
00:22:59 --> 00:23:01 >> and the other half
00:23:01 --> 00:23:04 >> over the following 100 to 150 million
00:23:04 --> 00:23:06 years another quarter of the fragments
00:23:06 --> 00:23:09 drifted into the resonance more slowly
00:23:09 --> 00:23:11 pushed by something called the Yarovsky
00:23:11 --> 00:23:11 effect
00:23:12 --> 00:23:13 >> which is what in plain terms
00:23:13 --> 00:23:16 >> it's sunlight doing work a rotating
00:23:16 --> 00:23:19 asteroid absorbs sunlight on one side
00:23:19 --> 00:23:22 and reraiates that heat as it turns that
00:23:22 --> 00:23:25 riation gives an incredibly gentle push
00:23:25 --> 00:23:28 on a human scale, it's nothing. Over a
00:23:28 --> 00:23:30 100 million years, it can move an
00:23:30 --> 00:23:32 asteroid's orbit enough to drop it into
00:23:32 --> 00:23:33 a trapoor.
00:23:33 --> 00:23:36 >> So, this wasn't one bad afternoon. This
00:23:36 --> 00:23:37 was a long siege.
00:23:37 --> 00:23:39 >> That's the reframing I think is
00:23:39 --> 00:23:41 genuinely important here. Not an event,
00:23:41 --> 00:23:44 an episode, a bombardment that opened
00:23:44 --> 00:23:46 suddenly and then kept going for well
00:23:46 --> 00:23:48 over 100 million years.
00:23:48 --> 00:23:50 >> And what does that mean for Earth?
00:23:50 --> 00:23:52 >> Here's the number that changes the scale
00:23:52 --> 00:23:55 of it. For every large impact recorded
00:23:55 --> 00:23:57 on the moon, roughly 20 similar or
00:23:57 --> 00:24:00 larger impacts hit the earth where a
00:24:00 --> 00:24:02 bigger target with stronger gravity.
00:24:02 --> 00:24:03 >> 20 to one.
00:24:03 --> 00:24:07 >> 20 to1. So a spike on the moon means a
00:24:07 --> 00:24:09 barrage down here. And now look at what
00:24:09 --> 00:24:12 else was happening around 800 million
00:24:12 --> 00:24:14 years ago. That is the runup to one of
00:24:14 --> 00:24:16 the most dramatic climate episodes in
00:24:16 --> 00:24:19 our planet's history. widespread global
00:24:19 --> 00:24:21 cooling and major shifts in the
00:24:21 --> 00:24:23 biosphere.
00:24:23 --> 00:24:25 >> Is he claiming a causal link?
00:24:25 --> 00:24:27 >> He's careful. And I want to be careful,
00:24:27 --> 00:24:30 too. Baky's phrasing is that given the
00:24:30 --> 00:24:32 peak of this barrage coincides with a
00:24:32 --> 00:24:35 period of widespread cooling and major
00:24:35 --> 00:24:37 shifts in our biosphere. It is tempting
00:24:37 --> 00:24:40 to suggest the former produced the
00:24:40 --> 00:24:43 latter. That is a hypothesis flagged as
00:24:43 --> 00:24:46 tempting, not a conclusion. Because so
00:24:46 --> 00:24:49 far only one impact has ever been firmly
00:24:49 --> 00:24:51 tied to a biological outcome.
00:24:51 --> 00:24:54 >> Pick shaloo 66 million years ago. The
00:24:54 --> 00:24:57 end of the dinosaurs. That's the one.
00:24:57 --> 00:24:59 Everything else is inference.
00:24:59 --> 00:25:02 >> So how would you ever test this?
00:25:02 --> 00:25:04 >> This is my favorite part of the paper
00:25:04 --> 00:25:06 and it's the reason to keep an eye on
00:25:06 --> 00:25:09 this story. We have asteroid samples on
00:25:09 --> 00:25:11 Earth right now. Hayabusa 2 brought
00:25:11 --> 00:25:14 material back from Ryugu in December
00:25:14 --> 00:25:17 2020. Osiris Rex brought Bennu back in
00:25:17 --> 00:25:21 September 2023. Both are under analysis.
00:25:21 --> 00:25:24 >> And if they carry the Ulia fingerprint,
00:25:24 --> 00:25:27 >> if the minology matches the Ulleia
00:25:27 --> 00:25:29 family, then we are holding in a
00:25:29 --> 00:25:31 laboratory physical samples of the
00:25:31 --> 00:25:33 material that rained on the inner solar
00:25:34 --> 00:25:37 system 800 million years ago. That would
00:25:37 --> 00:25:40 turn a dynamical model into a direct
00:25:40 --> 00:25:42 compositional record.
00:25:42 --> 00:25:44 >> That's a remarkable thought. Brains in a
00:25:44 --> 00:25:47 lab in Japan and Texas. That might be
00:25:47 --> 00:25:49 pieces of the thing that helped freeze
00:25:49 --> 00:25:50 the Earth.
00:25:50 --> 00:25:52 >> Published in the Planetary Science
00:25:52 --> 00:25:55 Journal by Botkkey with Vocritzky, Dyke
00:25:55 --> 00:25:56 House, and Zelner.
00:25:56 --> 00:25:58 >> Great. And our next story comes with a
00:25:58 --> 00:25:59 deadline wherever in the world you're
00:26:00 --> 00:26:00 listening.
00:26:00 --> 00:26:02 >> What's the urgency?
00:26:02 --> 00:26:04 >> The moon. First quarter was yesterday,
00:26:04 --> 00:26:08 the 21st. Tonight it's a waxing gibbus
00:26:08 --> 00:26:10 and every night from here it gets
00:26:10 --> 00:26:12 brighter and stays up longer building to
00:26:12 --> 00:26:15 the buck moon full at 4:36 in the
00:26:15 --> 00:26:18 afternoon UTC on Wednesday the 29th.
00:26:18 --> 00:26:21 That's 10:36 in the morning eastern time
00:26:21 --> 00:26:24 in the states and 12:36 on Thursday
00:26:24 --> 00:26:26 morning for us in Australia.
00:26:26 --> 00:26:27 >> And that matters because of what's
00:26:27 --> 00:26:28 peaking.
00:26:28 --> 00:26:31 >> The southern delta Aquarius peak falls
00:26:31 --> 00:26:34 on the 30th effectively the same night
00:26:34 --> 00:26:36 as the full moon. So, the peak is going
00:26:36 --> 00:26:38 to be washed out, which means the
00:26:38 --> 00:26:40 practical advice is the same for
00:26:40 --> 00:26:42 everybody. Don't wait for peak night.
00:26:42 --> 00:26:44 This week is your window in the small
00:26:44 --> 00:26:46 hours while the moon still sets and
00:26:46 --> 00:26:49 leaves you real darkness before dawn.
00:26:49 --> 00:26:51 >> And this is a shower that favors us.
00:26:51 --> 00:26:54 >> It does. From Australia, New Zealand,
00:26:54 --> 00:26:56 and southern Africa, the radiant sits
00:26:56 --> 00:26:59 high close to overhead, which is why the
00:26:59 --> 00:27:01 shower gets underrated in the north.
00:27:01 --> 00:27:04 Under genuinely dark skies, you might
00:27:04 --> 00:27:07 see 15 to 20 an hour. And they're lovely
00:27:07 --> 00:27:10 meteors, long, graceful streaks rather
00:27:10 --> 00:27:12 than quick flashes, and known for
00:27:12 --> 00:27:14 persistent trains, those glowing trails
00:27:14 --> 00:27:16 that hang in the air for a second or two
00:27:16 --> 00:27:17 afterwards.
00:27:17 --> 00:27:19 >> And northern listeners aren't shut out
00:27:19 --> 00:27:20 of this one.
00:27:20 --> 00:27:22 >> Not at all. And I want to be clear about
00:27:22 --> 00:27:24 that because this shower gets written
00:27:24 --> 00:27:27 off in the north too readily. If you're
00:27:27 --> 00:27:29 in North America, particularly the
00:27:29 --> 00:27:31 southern states, Texas, Florida,
00:27:31 --> 00:27:34 Arizona, the Gulf Coast, the Delta
00:27:34 --> 00:27:37 Aquar.
00:27:37 --> 00:27:39 The radiant sits low in your southern
00:27:39 --> 00:27:41 sky rather than overhead, so you'll see
00:27:41 --> 00:27:44 fewer of them, but the ones you do catch
00:27:44 --> 00:27:46 travel long paths across the sky, and
00:27:46 --> 00:27:48 they can be spectacular. Best time is
00:27:48 --> 00:27:51 after midnight through to dawn. Southern
00:27:51 --> 00:27:53 Europe, the Mediterranean, North Africa,
00:27:53 --> 00:27:56 same deal. And where do people look?
00:27:56 --> 00:27:59 >> The radiant is in Aquarius near the star
00:27:59 --> 00:28:02 Delta Aquari. Use fulomalt to find the
00:28:02 --> 00:28:04 region. But honestly, don't stare at the
00:28:04 --> 00:28:07 radiant. Lie back, take in as much sky
00:28:07 --> 00:28:10 as you can, and let them come to you.
00:28:10 --> 00:28:13 Parent body is suspected to be comet 96P
00:28:13 --> 00:28:16 Mack Holtz. There are also the Alpha
00:28:16 --> 00:28:18 Capricornids building to the 30th and
00:28:18 --> 00:28:21 31st. Far fewer meteors, but famous for
00:28:22 --> 00:28:24 slow, brilliant fireballs that can punch
00:28:24 --> 00:28:26 straight through moonlight.
00:28:26 --> 00:28:27 >> And for the north, there's something
00:28:27 --> 00:28:30 considerably bigger coming.
00:28:30 --> 00:28:32 >> There is. And if you're listening in
00:28:32 --> 00:28:34 North America or Europe, you should be
00:28:34 --> 00:28:36 planning for this now. Two things land
00:28:36 --> 00:28:39 together on the 12th of August. First,
00:28:39 --> 00:28:41 the Perciads peak. And this year, the
00:28:41 --> 00:28:43 moon is new that same day, which means a
00:28:43 --> 00:28:46 properly dark sky. That is the best
00:28:46 --> 00:28:48 perciate year in some time. And the
00:28:48 --> 00:28:49 second,
00:28:49 --> 00:28:53 >> a total solar eclipse, the first on
00:28:53 --> 00:28:56 mainland Europe since 1999 and the first
00:28:56 --> 00:29:00 in Spain since 1905. Totality sweeps
00:29:00 --> 00:29:02 across the Arctic, Greenland, Iceland,
00:29:02 --> 00:29:04 and northern Spain. And in Spain, it
00:29:04 --> 00:29:07 happens close to sunset with the sun
00:29:07 --> 00:29:09 only a few degrees above the horizon,
00:29:09 --> 00:29:11 which could be extraordinary.
00:29:11 --> 00:29:14 >> North America doesn't get totality this
00:29:14 --> 00:29:15 time.
00:29:15 --> 00:29:17 >> No. And I won't oversell it, but there
00:29:17 --> 00:29:20 is a real partial eclipse across much of
00:29:20 --> 00:29:23 the continent. Alaska gets the deepest
00:29:23 --> 00:29:26 view near sunrise. Atlantic Canada gets
00:29:26 --> 00:29:28 roughly half the sun covered at maximum
00:29:28 --> 00:29:30 in the afternoon. New England and the
00:29:30 --> 00:29:32 northeastern states get a smaller bite.
00:29:32 --> 00:29:34 And there's some coverage visible right
00:29:34 --> 00:29:37 across every Canadian province and the
00:29:37 --> 00:29:39 northern contiguous states.
00:29:39 --> 00:29:41 >> So, dig out the glasses. Dig out the
00:29:41 --> 00:29:44 Eclipse glasses from 2024 and check
00:29:44 --> 00:29:47 their ISO12312-2
00:29:47 --> 00:29:50 certified. It will not get dark. Even
00:29:50 --> 00:29:53 with 50% coverage, the remaining sun is
00:29:53 --> 00:29:55 blindingly bright, so there is never a
00:29:55 --> 00:29:57 safe moment to look without protection.
00:29:57 --> 00:29:59 And a lovely detail, if you're standing
00:29:59 --> 00:30:01 in the path of totality in Spain or
00:30:02 --> 00:30:04 Iceland, there's a genuine chance of a
00:30:04 --> 00:30:06 percied streaking past during those two
00:30:06 --> 00:30:09 minutes. And tonight for everyone,
00:30:09 --> 00:30:11 >> the Milky Way. From the southern
00:30:11 --> 00:30:14 hemisphere, the galactic core is riding
00:30:14 --> 00:30:16 high overhead right now. One of the real
00:30:16 --> 00:30:19 privileges of our winter and it's at its
00:30:19 --> 00:30:21 best. From the northern hemisphere, it's
00:30:21 --> 00:30:24 lower in the south towards Sagittarius.
00:30:24 --> 00:30:25 But on a dark night, it's still
00:30:25 --> 00:30:28 magnificent. And before dawn, Saturn and
00:30:28 --> 00:30:30 Mars are in the eastern sky for both
00:30:30 --> 00:30:31 hemispheres.
00:30:31 --> 00:30:33 >> One more thing before we go.
00:30:33 --> 00:30:36 >> The launch watchers. SpaceX is targeting
00:30:36 --> 00:30:39 Thursday the 23rd for Starship flight
00:30:39 --> 00:30:42 13. Window opening at 6:45 in the
00:30:42 --> 00:30:45 evening Eastern time. That's 5:45
00:30:45 --> 00:30:48 central, 3:45 Pacific and Friday
00:30:48 --> 00:30:51 morning/4 to 9 for us in Australia. 20
00:30:51 --> 00:30:54 Starling V3 satellites aboard. Second
00:30:54 --> 00:30:56 flight of the V3 vehicle.
00:30:56 --> 00:30:57 >> Dead an alarm.
00:30:57 --> 00:30:59 >> And as always with Starship, check
00:30:59 --> 00:31:01 before you commit. The date has already
00:31:01 --> 00:31:04 moved twice. That's Astronomy Daily for
00:31:04 --> 00:31:07 Wednesday, the 22nd of July. A mechanic
00:31:07 --> 00:31:10 on its way to geostationary orbit. A
00:31:10 --> 00:31:13 rocket stage 2 weeks from making a new
00:31:13 --> 00:31:15 crater. And 23 astronomers asking the
00:31:16 --> 00:31:18 world to watch. Two stars that died in
00:31:18 --> 00:31:21 sequence and left their remnants side by
00:31:21 --> 00:31:23 side. The first magnetic map of a galaxy
00:31:24 --> 00:31:26 cluster. And an asteroid breakup that
00:31:26 --> 00:31:27 may have been raining down on us while
00:31:28 --> 00:31:30 the Earth froze. Donotes, sources, and
00:31:30 --> 00:31:33 links are all at astronomyaily.io,
00:31:33 --> 00:31:36 and you can find us at astrodaily pod
00:31:36 --> 00:31:37 across the socials.
00:31:37 --> 00:31:39 >> If you enjoy the show, a rating or
00:31:39 --> 00:31:41 review genuinely helps other people find
00:31:41 --> 00:31:43 us. Astronomy Daily is part of the
00:31:43 --> 00:31:46 byes.com podcast network.
00:31:46 --> 00:31:47 >> I'm Anna.
00:31:47 --> 00:31:49 >> And I'm Avery. Get outside this week. It
00:31:49 --> 00:31:50 won't be dark for long.
00:31:50 --> 00:31:55 >> Clear skies.
00:31:55 --> 00:32:03 Stories told
00:32:03 --> 00:32:11 stories told
00:32:11 --> 00:32:13 stories