From Solar Storms to Martian Canyons: The Latest in Space News

0:00 Anna: Hi, everyone. Welcome back. Last November, the sun fired off a burst of particles so energetic that some of them made it all the way down to the ground. Within the hour, scientists in Britain were letting go of weather balloons. Avery: And one of those balloons rising out of Shetland flew straight into a radiation environment that crossed the international aviation warning lines. Meanwhile, a passenger jet was over the Atlantic heading for New York. Anna: Today. What a solar radiation storm actually looks like from inside the atmosphere.

0:37 Plus a, uh, canyon on Mars that is still breaking, the most violent star Kepler ever watched, and a piece of rocket that landed in a palm oil plantation in Borneo. Avery: This is Astronomy daily for Thursday 22nd October 2026. I'm Avery. Anna: And I'm Anna. Let's get into it. Avery: Okay, why don't you kick things off then, Anna? Anna: On the 11th of November last year, at about 20 past 10 in the morning UTC, the sun produced what's called a ground level enhancement. It's the 77th ever recorded, so it goes by gle77 and it was the largest in almost 20 years.

1:20 Avery: Lets unpack the name because it's doing a lot of work most of the time. Particles from the sun hit the top of the atmosphere and, um, that's the end of them. Um, they collide with air molecules high up and their energy gets spread out and absorbed. Anna: But occasionally a solar eruption accelerates protons to such high energies that they smash into the upper atmosphere and set off a cascade, a shower of secondary particles, including neutrons, that reaches all the way down to the surface.

1:51 Instruments on the ground called neutron monitors see the count jump. That's a ground level enhancement. They're rare. 77 of them since the records began in the 1940s. Avery: And this one came off the back of an X5 class solar flare during the busiest stretch of the current solar cycle. Anna: A paper published on Tuesday in the journal Space Weather pulls together what the authors describe as the most comprehensive set of measurements ever made through the atmosphere during one of these events. It's led by Fraser Baird and Ben Cluer at the University of Surrey with the UK Met Office and the Royal Netherlands Meteorological Institute.

2:33 Avery: Three kinds of instrument all running at once. First, a, uh, network of neutron monitors on the ground stretching from Cornwall in the far southwest of England all the way up to Shetland. The authors point out that a decade ago the UK had no operational sensors like this at all. Anna: Second, radiation monitors on commercial passenger jets flying out of Heathrow. And third, radiation monitors carried up on weather balloons, the same kind of balloons the Met Office launches every day for forecasting rising to more than 30 kilometres.

3:11 Avery: And the balloons were ready when the alerts came in from neutron monitors around the world. The launches were triggered within the hour. Anna: The headline is how uneven it was on the ground. The neutron monitors saw a big early peak in the north and a smaller peak in the south about an hour later. Same storm, same small country, different experience. Avery: Up high, the contrast was even sharper. The balloon from Lerwick and Shetland went through levels above the International Civil Aviation Organisation's moderate advisory threshold.

3:47 At, uh, business jet cruising heights several hours after the storm peaked, and higher still at the altitudes where supersonic aircraft fly, it measured twice the severe threshold. Anna: Meanwhile, balloons launched from Camborn and Cornwall and from the Netherlands saw no significant rise at all. Avery: Then the aircraft Heathrow to New York JFK flight that departed at quarter to 12 UTC, right in the thick of it, recorded a rise in total radiation dose of 42.6% over normal background. That's a big jump.

4:23 But it did not cross any of the international warning thresholds. Anna: And a Heathrow to Newark flight that left six hours later saw no significant increase at all. Avery: A quick note from us on that may see 46% quoted in coverage, which is the figure in the university's press release. The paper itself says 42.6 and that's the one we're using. Anna: So why would Shetland and Cornwall, 1,000 kilometres apart, have such different days? Avery: It comes down to Earth's magnetic field near the equator.

5:00 The field lines run roughly parallel to the ground, so an incoming charged particle has to cross them and only the most energetic ones make it through toward the poles. The field lines dip down into the Earth and particles can spiral in along them much more easily. Physicists call the threshold a, uh, cutoff. And it falls the further you go towards the poles. Anna: So every step north lowers the bar. Shetland at 60 degrees north lets in particles that Cornwall at 50, keeps out. That's why polar flight routes are the most exposed and why a, uh, strong storm can push the exposed zone further from the poles.

5:40 Avery: And the timing differences tell you the particles didn't arrive as one smooth wave. They came in from a preferred direction, which is why the authors describe the event as strongly anisotropic. Anna: Here's the part that I think is the real story. The current international advisory system run through ICAO relies mostly on models informed by measurements on the ground and in space. And during GLE 77, no ICAO advisory was issued at all. Avery: Yet one balloon was sitting well above the moderate line.

6:18 And at supersonic altitudes above the severe line, the Author's argument is that direct measurements through the atmosphere need to be part of the system because these events are so patchy that a model tuned to the average can miss what's happening over one corner of the map. Anna: Krista Hammond, space weather manager at the Met Office and a co author, described it as the first time radiation data had been collected through the atmosphere during a, uh, space weather event. In this way. Avery: And it isn't only about people.

6:51 Aircraft now rely on sensitive electronics and energetic particles can flip bits in a computer. Airbus recalled around 6,000 A320 family jets for a software fix late last year after an incident blamed on cosmic radiation. To be clear, that one wasn't during a solar storm. It was a single stray particle. But it's the same kind of particle that storms deliver in bulk now, some Anna: proportion, because this is the kind of story that can sound scarier than it is. Back in episode 193, we said a long haul flight gives you a dose roughly comparable to a chest x Ray.

7:33 A 40% rise on top of that is a 40% rise on a small number. For an occasional passenger, it's not a health worry. Avery: Where it matters is for crews who fly hundreds of hours a year and for planning at the margins when to reroute, when to fly a bit lower, when it's worth holding a flight on the ground. That's what the thresholds are for. Anna: And it's one event measured over one country. The authors aren't claiming a rule for every storm, they're showing how much the picture changes when you actually go up and measure it.

8:09 Avery: There's no Australian team on this paper, so let's be straight about that. But there is a direct line to us. ICAO's global space weather advisories come from four centres and one of them is a consortium of Australia, Canada, France and Japan. Within it, our own Bureau of Meteorology and Meteo France are the ones who issue the advisories. That service started in November 2019. Anna: So the question this paper raises, whether advisories should lean more on direct measurement, lands on desks in Australia too.

8:43 And the physics doesn't care which hemisphere you're in. Routes between Australia and South America run far south towards Antarctica, which is exactly where the magnetic shield is thinnest. Avery: If you've been with us a while, this sits on a familiar dial. In episode 192 it was the potential for a superflare. In 193, aviation dose running higher at solar minimum. And in 196, in the same journal, the 1848 telegraph storm in Exeter today. It's what the strongest event of the cycle so far actually did to the sky over Britain.

9:22 Anna: Balloons into the storm. Sometimes the best instrument is the one you can launch in an hour from Avery: Earth's sky to the far side of Mars. Valles Marineris is the largest canyon system in the solar system, about 3,900 kilometres long, up to 600 wide and more than nine kilometres deep. Lay it across Australia and it would run from Perth to past Brisbane. Anna: And it formed billions of years ago. The question has always been whether it's a fossil or whether it's still moving. Avery: A paper published last Thursday in Nature Communications says it's still moving.

10:05 Jung Hoon Sung and Do Yeon Kim at Imperial College London with Folarin Kolawole at Columbia University went back to a single Marsquake recorded by NASA's InSight lander, known as S0976A. Anna: That's SOL 976, 25-8-2021. And it was special. It came from the far side of Mars, from the lander, and it's the only Marsquake Insight ever located in the planet's western hemisphere. Avery: Insight, huh? Had one seismometer, which makes this hard with one station. You can't triangulate in the usual way, but by modelling the shapes and strengths of the waves that bounced off the Martian surface on their way to the lander, the team reconstructed what happened at the source.

10:56 Anna: The answer? A, uh, strike slip fault where two blocks of crust slide sideways past each other about 20 to 40 kilometres down beneath the western end of the canyon near East Chasma, a magnitude around three and a half. Avery: They tested the alternatives. Meteoroid impact or a, ah, landslide. Just can't reproduce the waves. And a landslide big enough would have needed at least 10 million cubic metres of rock and left a fresh scar hundreds of metres to a kilometre across. Orbital images taken afterwards covering about half the likely source area show nothing like it.

11:36 Anna: So what's pushing on it? The authors point to a combination the whole planet slowly cooling and contracting, the enormous weight of the Tharsis volcanic region next door and the canyon itself, where so much rock has been eroded away that the crust has been unloaded. Faults made billions of years ago are still weak enough to slip under today's stresses. Avery: Now there's a lovely Australian footnote here. To prove the single seismometer method works, the team tested it on a magnitude 6.5 earthquake in Nevada in 2020 recorded at, ah, just one station on the other side of the world.

12:18 The global Seismic Network Station in Canberra. The method recovered the right kind of fault and the right depth. Anna: A disclosure the data are from 2021 and insight stopped working in 2022. So this is a new analysis of an old recording and it's one quake located with a single instrument. No aftershocks were recorded, but the team calculates INSIGHT had only about a, uh, one in a thousand chance of catching one. Avery: From that, it also fits a pattern we've been following. On Tuesday in episode 209, it was the Moon still shrinking and cracking.

13:00 Mars now joins it. Worlds without plate tectonics still have faults, and the old ones keep doing the Anna: work from quakes to flares. While we're on the subject of things that erupt, NASA's Kepler telescope watched about 150,000 stars for four years. And of all of them, the one that produced the most energetic flares was a red giant called KIC 2852961. Avery: Not the biggest star, not the brightest, just by a wide margin, the most violent. Anna: A team at the Konkoly Observatory in Budapest led by Zolt Kovari already showed back in 2020 that its superflares were follow the same physics as flares on very different kinds of stars.

13:52 Now they've worked out what powers it, and the answer involves a partner. Avery: With new radial velocity measurements. They confirm the giant is in a close binary with a faint dwarf companion. When the giant swelled up to its current size, about 12 times the radius of the sun, the tidal pull between the two became enormously stronger. The effect scales with the eighth power of the ratio of their separation to the star size. So swelling up changes everything. Anna: Those tides have been forcing the giant to spin in step with its orbit and the orbit to become circular.

14:30 And it's nearly there. Nearly, but not quite. Avery: That not quite is the key because it isn't fully locked. Different latitudes of the star still rotate at slightly different speeds. That differential rotation drives a magnetic dynamo, builds enormous star spots that store magnetic energy and twists the field lines above them until they snap. That's a super flare. Anna: And the companion isn't pulling the trigger directly. The team looked for flares bunching at particular points in the orbit and found none.

15:05 The companion built the engine. The giant holds the ignition key. Avery: A disclosure this is a, uh, preprint from earlier this month. The observatory says it's been accepted by Astronomy and Astrophysics, but the journal version isn't out yet. And for our southern listeners, the Kepler field is in Cygnus and Lyra northern patch of sky. Anna: But it pairs nicely with our lead. That was a flare on our own star, measured from inside our atmosphere. This is the same magnetic physics turned up much, much further on someone else's.

15:44 Avery: Closer to home now. Very close, actually. On Sunday evening, residents near the town of Sampit in central Kalimantan, Indonesian Borneo, heard a loud bang. Anna: On Monday morning, A plantation worker named Wardy Tamroni found a large metal object in a palm oil plantation about three kilometres from the company housing where he and his colleagues live. Local police described it as an aluminium plate, up to nine metres long, irregular in shape, with burn marks. Avery: On Tuesday, a second rounder piece turned up about a kilometre away.

16:25 Both are being examined at a nearby military air base. Indonesia's Civil Aviation Authority says nobody was hurt, nothing was damaged and there's no radiation or toxicity risk. Anna: Mr. Tamroni said the workers had already gone home for the day, so nobody was in that part of the plantation when it came down. Avery: Indonesia's National Research and Innovation agency, Brin M says the debris appears to come From a Chinese Zui2e rocket, a, uh, Zuwei2e launched on the 14th of October from northwest China, carrying 10 satellites.

17:02 Anna: That attribution is preliminary and we'll treat it that way. China's space agency couldn't be reached for comment and nobody has said yet which part of the rocket this might be. Avery: Brin researcher Thomas Jamaluddin made the general point not, um, everything burns up on RE entry and, um, the more heat resistant parts can survive to the ground. Most of it lands in the ocean. Simply because most of the planet is ocean. Anna: The odds of any one person being hit are still tiny, lower than being struck by lightning, according to the European Space agency.

17:38 But ESA's own space debris Office says RE entry risk grew considerably between 2019 and 2024 simply because so much more Avery: is being launched and this region has history. In 1979, pieces of the Skylab space station came down around Esperance in Western Australia. Today's story is a reminder that uncontrolled RE entries still happen and that the people underneath usually get no warning at all. We're also still waiting on the RE entry of NASA Swift Observatory, which NASA hasn't yet given a date for.

18:13 Anna: First, a, uh, correction. On Wednesday's episode, we said NASA's Artemis update was Thursday at 2pm Eastern. The time was right, but the day was wrong. It's Friday the 23rd at 2pm Eastern. That's 11am on the U.S. west Coast, 7pm in London and 5am Saturday here in Sydney. Our apologies. We'll bring you what NASA says in Avery: the weekend wrap and ESA's Hara spacecraft was due to fire its thrusters again early this morning European time. This is its second braking burn, about 31 minutes long following the 93 minute burn last week.

18:53 It's meant to deliver most of the remaining slowdown. HERA needs to match the speed of the Didymos asteroid pair and correct for any shortfall from the first. Anna: ESA confirmed last week's burn the following day, so we expect word on this one shortly after that. Three smaller manoeuvres later this month should bring Hera's speed relative to the asteroids to down to almost zero ahead of arrival in November at the scene of NASA's DART impact. Avery: Time to look up and this week both hemispheres get something, though not the same thing.

19:29 Anna: First Venus. It reaches inferior conjunction on Saturday, passing between Earth and the Sun. The moment falls at about 2 in the afternoon UTC on Saturday. 10 in the morning in New York, 7 in Los Angeles, 23 in the afternoon in London and around 1 o' clock early on Sunday morning in Sydney. Avery: At that point it's only about six and a half degrees from the Sun. Its disc is huge, more than a minute of arc across. But the lit side faces away from us and um, the glare makes it effectively invisible.

20:04 Anna: So please don't go hunting for it. Never point binoculars or a telescope anywhere near the Sun. Looking at the sun itself, even briefly, needs a proper solar filter that meets the international standard ISO 123122. And sunglasses are not enough. Venus will reappear in the morning sky in a couple of weeks and it's worth the wait. Avery: Mercury, on the other hand, is a gift to the south this week from Sydney Tonight it's about 21 degrees above the western horizon at sunset and it stays up well into dusk.

20:41 Anna: Compare that with about eight and a half degrees from Los Angeles, six from New York and barely two from London. It's the same spring evening geometry we've talked about before. The line of the planets stands up steeply from the southern horizon at dusk this time of year and lies flat in the north. Avery: Mercury is fading though from about magnitude half now to past magnitude two by the end of the month. So southern viewers, this weekend is your window. Anna: Everyone gets this one on Saturday evening.

21:18 The waxing gibbous moon sits near Saturn from Sydney at ah, dusk around 20 to 8. Both are about 27 degrees up, roughly six and a half degrees. Avery: Apart from Los Angeles and New York, they're lower around 15 degrees up at dusk, about 8 to 10 degrees apart and from London, about 6 degrees apart but low, with Saturn under 10 degrees. So find a clear horizon to the southeast. Anna: The Moon is full on Monday at 11 minutes past 4 UTC. That's quarter past three Monday afternoon in Sydney. So Sunday night is your best look.

21:57 Here in the Americas, it falls on Sunday evening. In the north, it's the hunter's moon. Avery: And, um, a clock note for our northern listeners. The UK and um, Europe fall back an hour this Sunday the 25th. The United States follows on the 1st of November. Anna: Now the North's turn. Before dawn, Mars and Jupiter are drawing together in the eastern sky. They're about nine and a half degrees apart now four and a quarter by the 5th of November, and closest at about one and a quarter degrees around Avery: the 15th from Los Angeles and New York.

22:33 At first light, Mars is around 60 degrees up and Jupiter around 55. London gets them at about 50 and 45. From Sydney, they're lower, about 25 and 22. So Southern watchers need a clear eastern view. Anna: And while you're out before dawn, the tail of the Orionid meteor shower is still running. The radiant just above the red star Betelgeuse is about 40 degrees up from Sydney before dawn and higher 50 to 65 degrees from the northern cities. Rates are past their peak and the bright moon sets late, so the hour before dawn is best.

23:15 Avery: So the south gets Mercury and a high moon and Saturn. The north gets the planets before dawn and the higher meteor radiant, Fair Trade. Anna: That's the show today. Weather balloons that flew into the biggest solar radiation storm in almost 20 years. A Martian canyon that's still breaking. The companion star that built a superflare engine and rocket debris in a Borneo plantation. Avery: Show notes and sources [email protected] and if you've got a question you'd like us to chase, the contact form is on the site.

23:55 Some of our best segments have started there. Anna: Tomorrow we'll have word on Hera's second burn and on Saturday, the weekend wrap, including whatever NASA says about Artemis. Avery: I'm Avery. Anna: And I'm Anna. From all of us at ah, Astronomy AstroDailyPod and the bytes.com podcast network, clear Skies.