Launch Day for Swift's Rescue, ISS Spacewalk, and Unraveling the Secrets of the Cosmos

0:00 Anna: Good morning and welcome to Astronomy Daily. I'm Anna. Avery: And I'm avery. It's Tuesday, June 30, 2026, and today is launch day. Anna: After weeks of watching this story build, we finally get to say it. A rescue mission for NASA's Swift observatory is heading to the launch pad, or rather the launch aircraft today. Avery: Plus a spacewalk happening live on the iss. A galaxy cluster that's breaking cosmology's rulebook. A quiet nursery hidden in the most violent part of our galaxy. A newly confirmed fossil galaxy near Andromeda.

0:35 And why today is Asteroid Day. Anna: Vic stories one very busy Tuesday. Let's get into it. We've been tracking this one for weeks. And Today's the day NASA's Neil Gerald Swift, observatory, 22 years old, still hunting gamma ray bursts, has been losing altitude faster than expected thanks to solar activity. Avery: Without help, Swift faced a real chance of an uncontrolled re entry by the end of this year. So NASA contracted a m small Arizona company, Catalyst Space Technologies, to build a robotic rescue spacecraft called Link in under nine months, a job that would normally take two years.

1:15 Anna: Link is about the size of a, uh, fridge. Three robotic arms, lidar sensors, ion thrusters. Today it launches from Kwadrilin Atoll in the Marshall Islands. Carried under the belly of Stargazer, the last aircraft worthy Lockheed, Lockheed Tristar in the world been dropped and lit on a Northrop Grumman Pegasus xl, the very last Pegasus XL ever to fly. Avery: Launch window opened at 6:23am Eastern. That's this evening here in Australia. As of our recording, NASA and Northrop Grumman have the mission status listed as go.

1:50 Anna: If it works, Link will spend months gently grappling and nudging Swift back up to a safe altitude. Swift was never built for being serviced. No docking port, no handholds. So this will be delicate historic work. Avery: Rat Kranko, the Swift principal Investigator at Goddard, put it Simply. Swift is NASA's multi tool for studying the cosmos. Today we find out if that multitool gets a second life. Anna: Fingers crossed for a clean release and a good first signal from Link. We'll keep you posted as uh, this story develops.

2:23 Avery: Story two takes us to the International Space Station, where NASA astronauts Chris Williams and Jessica Meir are stepping outside today to fix a wrist joint on KANADRM2. Anna: KANADRM2 is the station's big robotic arm. It's been doing the heavy lifting, literally since 2001. Capturing cargo ships, repositioning modules, helping with spacewalks. But one of its wrist joints has been giving controllers trouble. Avery: The spacewalk kicked off at around 8:35am Eastern today. Williams and Meir will replace the faulty joint mechanism so the arm can keep operating with its full range of motion.

2:59 Anna: It's not the flashiest of stories, but it matters enormously. Without a fully functioning Canat Arm 2, a lot of station operations get a lot harder, from cargo capture to external Avery: maintenance routine, and the sense that NASA has done dozens of these repairs over the decades. But every spacewalk still carries real risk, and this crew is doing precise, fiddly work in a pressurized suit 400km up. Good luck to them. Anna: Story three is a genuine cosmological puzzle. A team led by Kyle Finner at Caltech's IPEC has used the James Webb Space Telescope to study a, uh, galaxy cluster called XLSSC122.

3:42 Avery: That distance puts it in an era astronomers call cosmic noon, when the universe was only about 3 billion years old and forming stars faster than at any point before or since. Galaxy clusters from that era are supposed to look young, loose, scattered, still pulling themselves together. Anna: XLSSC122 doesn't look like that. JWST caught it acting as a gravitational lens, bending the light of background galaxies into arcs, and it's now the most distant, strong lensing galaxy cluster ever found.

4:15 Avery: When the team measured how concentrated the cluster's core mass is, the number came back higher than current cosmological models say it should be allowed to be. The visible matter stars gas barely accounts for any of it. The rest is dark matter, packed in tighter than expected for something this early in cosmic history. Anna: Laid researcher Fenner was refreshingly honest about it. This could just be one extreme outlier in a normal distribution. Or it could be a sign that something in our models of how structure formed in the early universe needs revising.

4:51 Avery: Either way, it's a reminder of just how much JWST is rewriting the early chapters of cosmic history, one impossibly mature galaxy cluster at a time. From the very distant universe to our own backyard, the center of the Milky Way is one of the most violent neighborhoods in the galaxy, a churning storm of gas moving faster than the speed of sound. It's about the last place you'd expect to find a star quietly being born. Anna: And yet astronomers using the ALMA telescope array in Chile have mapped that chaos in detail and found exactly that a small, almost accidental pocket where the turbulent gas slows down, slowly settles, and begins gathering itself into the seeds of new stars.

5:36 Avery: It's a small, almost accidental discovery with big implications. It suggests that stars might take their very first steps the same way everywhere in the galaxy, even in the most hostile environments imaginable. Anna: And that includes very possibly our own Sun. Billions of years ago, the sun may well have condensed out of just this kind of brief island of stillness somewhere in the swirling chaos of a young turbulent galaxy. Avery: A nice thought for your next coffee break. Somewhere in that storm at the galactic center right now, the next generation of stars may already be quietly getting started.

6:13 Anna: Dory 5 is a lovely one. Equal parts cosmology and citizen science. Astronomers have just formally confirmed in the peer reviewed journal Astronomy and Astrophysics the discovery of Andromeda 36, an ultra faint dwarf galaxy orbiting our giant neighbor, the Andromeda Galaxy. Avery: This one was actually first spotted back in March by an amateur astronomer, Giuseppe Donatellio, visually combing through public survey images. Not an algorithm, a person scanning pictures by eye. Now, after follow up observations with the Gran Telescopio Canaris, the team has nailed down the details.

6:51 Anna: And what details? Andromeda 36th is roughly 12.5 billion years old, extremely metal poor, and one of the faintest, most compact dwarf satellites ever found around Andro. It's essentially a fossil from the universe's earliest stages. Avery: Astronomers think Andromeda did host close to a hundred of these tiny dwarf satellites, and only about half are currently known. Lead author Joanna Sakova made the point that even now, careful visual inspection by a trained eye is still finding things that automated machine learning searches miss.

7:25 Anna: A nice reminder that in astronomy, sometimes the best discovery tool is still a patient human looking closely at the data. Avery: And finally today, June 30th is asteroid day. It's a UN sanctioned day of awareness around planetary defense. And the date isn't random. Anna: It marks the anniversary of the Tunguska event back in 1908, when an asteroid or comet fragment exploded in the atmosphere over Siberia, flattening more than 2,000 square kilometers of forest. No crater, no warning. And to this day, it's the largest impact event in recorded history.

8:00 Avery: Asteroid Day exists to make sure we don't have to learn that lesson the hard way again. Around the world today, observatories, space agencies and science communicators are running events on planetary defense, tracking near Earth objects, deflection technology, and what we'd actually do if something was heading our way. Anna: And we do have a real success story to point to. NASA's DART mission already proved by physically slamming into the asteroid Dimorphos that we can measurably change an asteroid's path.

8:29 It's no longer just theory. Avery: So today's less about any single new discovery and, uh, more about the bigger picture. Thousands of astronomers, amateur and professional, quietly doing the unglamorous work of mapping the sky for the next Tunguska so that if it ever comes, we'll see it coming. And that wraps up a big Tuesday for Astronomy Daily. A rescue mission lighting up the Pacific sky, a spacewalk on the iss, and galaxies both impossibly old and impossibly young. Anna: If you enjoyed today's episode, please hit subscribe wherever you're listening and leave us a review.

9:06 It genuinely helps new listeners find the show. Avery: We're Anna, uh, and Avery. This has been Astronomy Daily, and we'll see you back here tomorrow. Clear skies, everyone. And good luck to Swift and Link tonight.

9:21 Mhm.

9:29 Anna: The stories.

9:38 Avery: Were told.