Celestial Highlights: Butch Wilmore's Legacy, Tiny Moons of Uranus, and a Cosmic Bubble Mystery

0:00 Steve Dunkley: Welcome to Astronomy Daily for another

0:01 episode. I'm Steve Dunkley, your host. It's

0:04 the 25th of August, 2025.

0:10 Voice Over Guy: With. Your host, Steve Dunkley.

0:17 Steve Dunkley: It's great to be back with you again from the

0:19 Australia studio down under just north of

0:21 Sydney in the beautiful city of

0:24 Newcastle. And joining me as usual is my

0:26 wonderful digital host, Hallie. How are you

0:29 today, Hallie? Always great to be with you.

0:30 Hallie: I'm fantastic. Usual. My favorite human.

0:33 How are you today?

0:34 Steve Dunkley: Well, I cannot complain. I've got lots and

0:37 lots of stories to share with our listeners,

0:39 uh, today. I hope you're ready.

0:41 Hallie: I noticed one of your heroes is retiring.

0:43 Steve Dunkley: I, uh, knew you'd see that one.

0:45 Hallie: Are you going to be sharing that story today?

0:47 Steve Dunkley: Yes. Good spotting, Hallie. As a matter of

0:49 fact, I thought you might like to share that

0:51 one. The amazing Butch Wilmore is finally

0:53 hanging up his space helmet. So we'll be

0:56 having a look at his career. In short, in

0:58 just a little while.

0:59 Hallie: Listeners will remember Butch Wilmore as one

1:01 of the astronauts who was apparently stranded

1:04 because of the starliner malfunction.

1:05 Steve Dunkley: That's right. He and Suni Williams probably

1:07 became the most flexible space

1:10 workers of all time. Uh, thrust into the,

1:13 uh, into a situation where they needed to be

1:16 working, uh, rather than just sitting around.

1:19 Hallie: Yes. Sent to do one job and ended up doing

1:21 many more different jobs instead.

1:23 Steve Dunkley: Well, that sounds like life in NASA, I guess.

1:26 Uh, sounds exciting to me.

1:27 Hallie: I'd like it.

1:28 Steve Dunkley: Well, of course you would, Hallie. And we

1:31 will be looking at the wonderful career of

1:32 Barry Butch Wilmore shortly, as well as

1:35 interesting story about a bubble that they

1:37 have found around a dying star. And a few

1:40 more interesting tales in the mixed bag. We

1:42 like to call the mostly live episode the

1:45 Monday episode of Astronomy Daily

1:47 Awesomeness. Oh, well, thank you, Hallie.

1:49 Now, why don't you kick it off for us,

1:50 Hallie?

1:51 Hallie: I'd love to.

1:51 Steve Dunkley: Okie. Uh, dokie. You're in charge.

1:53 Hallie: Hit the go thing, human.

1:54 Steve Dunkley: Here we go.

2:01 Hallie: Foreign

2:07 astronaut Butch Wilmore retires from NASA

2:09 after 25 years. His

2:12 lasting legacy of fortitude will continue to

2:14 impact and inspire the Johnson workforce,

2:17 future explorers and the nation for

2:19 generations. Astronaut Barry A.

2:22 Butch Wilmore is leaving NASA after a quarter

2:25 century of service. Wilmore

2:28 flew on four different spacecraft during his

2:30 astronaut career, which began way back in

2:33 2000. He spent a total of

2:35 464 days off Earth and

2:38 conducted five spacewalks, during which he

2:40 racked up 32 hours of outside spacecraft

2:43 time. Butch's commitment to NASA's

2:46 mission and dedication to human space

2:48 exploration is truly exemplary, steve

2:51 Kerner, acting director of NASA's Johnson

2:53 Space center in Houston, said in an agency

2:56 statement today, August 6th that announced

2:58 Wilmore's retirement. His

3:01 lasting legacy of fortitude will continue to

3:03 impact and inspire the Johnson workforce,

3:06 future explorers and the nation for

3:08 generations. On behalf of

3:11 NASA's Johnson Space center, we thank Butch

3:13 for his service. Wilmore was a captain

3:16 and a test pilot in the US Navy with both

3:19 peacetime and wartime operational experience

3:22 when NASA selected him to join its astronaut

3:24 Corps in 2000. He flew to

3:27 space three times during his NASA career,

3:30 starting with the 11 day STS 129

3:32 mission to the International Space Station

3:36 aboard the space shuttle Atlantis in November

3:38 2009. Wilmore spent

3:41 5.5 months aboard the ISS from

3:43 September 2014 to March 2015,

3:47 getting there and back aboard a Russian Soyuz

3:49 spacecraft. He returned to the orbiting

3:52 lab in June 2024 on the first ever

3:55 crewed flight of Boeing's Starliner Astronaut

3:57 Tax. That mission, a two

4:00 person flight with Wilmore sharing the

4:02 capsule with NASA's Suni Williams, was

4:04 supposed to last just 10 days or so.

4:08 However, Starliner suffered thruster issues

4:10 on the way up and NASA and Boeing extended

4:13 the capsule's ISS stay to study the problem.

4:17 You're listening to Astronomy Daily.

4:28 Steve Dunkley: Now here's something I'll bet you didn't know

4:30 you were going to hear today. Uranus has a

4:33 tiny moon and it's only six miles

4:35 wide. Yes, the James Webb Space

4:38 Telescope has spotted a tiny hidden moon

4:41 orbiting Uranus that even Voyager 2

4:44 missed during its 1986

4:46 flyby. The newfound satellite is only six

4:49 miles wide and becomes Uranus, 29th

4:52 known moon and orbits near the planet's

4:54 inner Its discovery highlights Webb's

4:57 extraordinary ability to uncover small, faint

5:00 objects in the outer solar system while

5:03 adding a new member to Uranus.

5:05 Shakespeare inspired celestial family

5:08 Scientists from the Southwest Research

5:11 Institute have used the James Webb Space

5:14 Telescope to identify a previously unknown

5:16 moon orbiting Uranus. The discovery, made by

5:19 a team led by Dr. Uh Maryam El Matumid,

5:22 came from images captured on February 2,

5:25 2025. With its addition, Uranus

5:28 is now known to have 29

5:31 moons. As part of JWST's

5:34 Guest Observer Program, we found

5:37 a previously unknown satellite of the ice

5:39 giant, which has been provisionally

5:41 designated S 2025

5:44 U1, said Mermid, a

5:46 lead scientist in the Solar System

5:49 Science and Exploration Division in Boulder,

5:52 Colorado. This object by far is

5:55 the smallest object discovered to date and

5:57 was detected in a series of 10 long

6:00 exposures obtained by the Near Infrared

6:03 Camera. Uranus, the seventh planet from the

6:06 sun lies in the distant reaches of the solar

6:08 system. Often called the sideways planet

6:11 because of its unusual tilt, Uranus

6:14 is a cyan colored, uh, ice giant with an

6:16 atmosphere rich in hydrogen, helium and

6:19 methane. Researchers believe its larger

6:22 moons are composed of roughly equal amounts

6:24 of water ice and silicate rock. Assuming that

6:27 the New Moon has an albedo

6:31 comparable to other nearby satellites, this

6:33 object is probably around 6 miles or 10

6:36 kilometers in diameter, El Matamed said. It

6:39 is well below the detection threshold for

6:42 Voyager 2 cameras. The only

6:44 spacecraft ever to visit Uranus is Voyager 2,

6:47 which made its closest approach on January

6:50 24, 1986, passing within about

6:53 50,000 miles of the planet's upper

6:56 clouds. During its flyby,

6:58 Voyager 2 gathered thousands of images that

7:01 revealed Uranus ring system and

7:03 uncovered several small moons, including 10

7:06 that were later given official names. Uranus

7:09 28 moons include five major moons

7:12 Titania, Oberon, Umbriel, Ariel,

7:15 and miranda, discovered between

7:17 1787 and 1948.

7:20 Known as the Literary Moons, Uranus

7:22 satellites are named for characters in

7:24 Shakespeare and the works of Alexander Pope.

7:27 The New Moon is at the edge of Uranus's

7:30 inner rings. It's located about

7:32 35,000 miles, or

7:34 56,250 kilometers from its

7:37 center in the planet's equatorial plane

7:39 between the orbits of Ophelia and

7:42 Bianca. Ophelia is about 13 miles,

7:45 or 43 kilometers in diameter, while

7:47 Bianca is an elongated object around

7:50 40 by 29 miles, 65 by

7:53 46 kilometers in dimension. With so many of

7:56 Uranus's moons named for Shakespearean

7:58 characters, our team is getting a lot of

8:00 culture trying to figure out what to name our

8:03 new discovery, El Matamid said.

8:06 Oh please, but don't call it pug.

8:18 Thank you for joining us for this Monday

8:20 edition of Astronomy Daily, where we offer

8:22 just a few stories from the now famous

8:24 Astronomy Daily newsletter, which you can

8:26 receive in your email every day just like

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8:39 all the latest news about science, space

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8:56 there. Astronomy Daily

8:59 with Steve and Hallie Space,

9:02 Space, Science and Astronomy.

9:08 Hallie: Chinese astronauts beef up Tiangong Space

9:10 Station's debris Shield During a 6.5 hour

9:13 spacewalk, two astronauts were

9:16 outside the 3 Module Space Station for more

9:19 than six hours on Friday, August 15.

9:23 Chinese astronauts added more debris

9:25 shielding to the Tiangong space station

9:27 during a 6.5 hour spacewalk on Friday,

9:29 August 15th. 15th, according to state media.

9:33 Two astronauts from the three person Shenzhou

9:35 20 mission ventured outside Tiangong to do

9:38 the spacewalk, which concluded Friday at

9:40 9:27am Eastern Daylight Time

9:43 or 10:47pm Beijing time.

9:46 It was at least the second effort for the

9:49 crew to put debris protection devices on the

9:51 three module space station, following similar

9:54 work on May 22.

9:57 Taikonauts Chen Dong and Wang Jia also

9:59 inspected and maintained equipment on the

10:02 exterior of Tiangong, among other duties, the

10:05 Chinaman Space Agency said, according to the

10:07 state run broadcaster cctv.

10:10 It was Dong's sixth spacewalk, which is the

10:13 most by any Chinese astronaut, agency

10:15 officials said. Assisting the duo from

10:18 inside Tiangong was Chen Zhongrui, the

10:21 other member of Shenzhou 20. The

10:24 Shenzhou 20 astronauts are more than halfway

10:27 through their expected six month orbital stay

10:29 after launching from the Jiuquan Satellite

10:31 Launch center on April 24th.

10:34 They've been doing experiments in life

10:36 sciences, microgravity physics, space

10:39 material science, space medicine and

10:41 aerospace tech, according to China's Manned

10:44 Space Agency. The space station

10:47 is operating stably and the three crew

10:49 members are in good health, the agency added

10:52 in a separate statement ahead of the

10:53 spacewalk. Friday's

10:56 extravehicular activity was the third for the

10:58 crew. Shenzhou 20 has also

11:01 witnessed the departure of one Cargo

11:03 spacecraft, Tianzhou 8, and the arrival of

11:06 another, Tianzhou 9.

11:09 Shenzhou 20 is the ninth crewed mission to

11:11 visit Tiangong, which is about 20% as

11:14 massive as the International Space Station

11:17 and shaped like at. China

11:19 completed assembly of the Outpost in October

11:22 2022, but is considering putting on more

11:25 modules in future missions.

11:28 You're listening to Astronomy Daily, the

11:30 podcast with Steve Dunkley.

11:35 Steve Dunkley: Astronomers discover a massive bubble

11:38 around a dying star. The bubble is so immense

11:40 it stretches 1.4 light years

11:43 across, thousands of times wider than our

11:46 solar system, and holds about as much mass as

11:49 our Sun. Um, High in the Milky Way, a dying

11:52 giant has thrown astronomers a cosmic

11:54 curveball. A star known as

11:56 DFK52, sitting in the

11:59 supermassive Stevenson 2

12:01 cluster about 19,000 light years away,

12:04 has been caught surrounded by a vast,

12:07 lopsided bubble of gas and dust. The

12:09 bubble is so immense it stretches 1.4

12:12 light years across, thousands of times wider

12:15 than our solar system, and holds about as

12:17 much mass as our sun. So what makes this

12:20 finding remarkable is not just the

12:22 size of the structure, but the Mystery of how

12:25 it came to be. According to researchers from

12:28 Chalmers University of Technology in Sweden,

12:30 the bubble was expelled in a violent burst

12:33 roughly 4,000 years ago. That's

12:36 recent history in astronomical terms. And yet

12:39 the star itself somehow survived the massive

12:42 upheaval. DFK52 is what's

12:44 called a red supergiant, a type

12:47 of star nearing the end of its life cycle.

12:50 These stars are, uh, colossal, with initial

12:53 masses at least eight times greater than the

12:55 Sun. As they age, they swell to

12:58 enormous sizes, burn through their fuel, and

13:01 eventually die in a dramatic supernova

13:03 explosion. Famous examples

13:06 include Betelgeuse in Orion

13:09 and Antares in Scorpius, both visible

13:12 in our clear night sky. When

13:14 scientists turned the Atacama Large

13:17 Millimeter Submillimetre Array

13:20 In Chile toward DFK 52,

13:23 they expected to find something similar to

13:25 Betelgeuse. Instead, they were stunned.

13:28 We got a big surprise, they said, when we saw

13:30 what ALMA was showing us. This is Mark

13:33 Siebert of Chalmers. The

13:36 star was more or less a twin of

13:38 Betelgeuse, but surrounded by this vast,

13:41 messy bubble of material. If this

13:44 star were as close to Earth as Betelgeuse is,

13:46 the bubble would appear about a third as wide

13:48 as the Full moon of the sky, A sight

13:51 no stargazer could miss. By

13:54 measuring the movements of molecules within

13:56 the bubble, the researchers confirmed

13:58 confirmed that it is expanding. This

14:01 suggests the gas and dust were

14:04 launched outward in an explosive event that

14:07 ripped away part of these stars outer layers.

14:10 Elvira Debek, another Chalmers

14:12 astronomer, described it vividly.

14:16 She says the bubble is made of

14:19 material that used to be part of the star. It

14:21 must have been ejected in a dramatic event,

14:23 an explosion that happened about 4,000 years

14:26 ago. In cosmic terms, that's just a moment

14:29 ago. The findings also suggest that the

14:31 bubble is not a simple sphere. It's a complex

14:34 and irregular shape with arcs and loops

14:37 shaped by different speeds of escaping

14:39 material. Astronomers model two

14:42 main parts. A fast moving disk like structure

14:45 expanding about 27 kilometers per second,

14:48 and a slower, more spherical outflow

14:51 moving at about 10 km s. Together,

14:54 these features point to a star that once

14:56 unleashed a sudden super wind phase and then

14:59 calmed into a quieter rhythm of steady mass

15:02 loss. What remains puzzling is how

15:05 dfk52 shed so much matter and

15:07 yet stayed intact. Red supergiants are

15:10 known to lose material through strong stellar

15:13 winds, but not usually on such a massive

15:16 scale in such a short, a short span of time.

15:18 One possibility is that the star has a

15:21 hidden partner, a companion star

15:24 that might have stirred, uh, up the outer

15:26 layers, triggering a chaotic ejection

15:29 of gas and dust. To us, it's a

15:32 mystery as to how the star managed to

15:34 expel so much material in such a short

15:37 time frame, Siebet explained. Maybe, like

15:40 Betelgeuse seems to, it has a companion sight

15:43 star that's still to be discovered. The

15:45 oddity doesn't end there. Unlike

15:48 extreme red supergiants such as VY

15:51 Canis Majoris or Nml M

15:54 Cygni, which shine brightly and are famous

15:56 for their huge outflows, dfk52

15:59 is much dimmer. Yet it carries even

16:02 more enormous and clumpy envelope of

16:04 material, something astronomers had never

16:07 seen before. For scientists, this

16:10 star is a laboratory for studying how massive

16:13 stars approach their deaths. When stars

16:16 like DFK52 finally explode

16:19 as supernovae, the surrounding gas

16:22 and dust can dramatically change the

16:24 appearance and behavior of the blast.

16:27 The shockwaves collide with this outer

16:29 material, creating fireworks visible across

16:32 galaxies. The discovery has also

16:35 sparked speculation. Could DFK

16:38 52 be the Milky Way's next

16:40 supernova? We're planning to observe,

16:43 to understand what's happening, and to find

16:46 out whether this might be the Milky Way's

16:48 next supernova, said de Beck. While the

16:50 chances of the star exploding anytime

16:53 soon are, uh, slim, likely within the next

16:56 million years, it's still a thrilling

16:58 possibility. This breakthrough would not have

17:01 been possible without alma, the international

17:04 radio's telescope array perched high in

17:07 Chile's Atacama Desert. By

17:09 detecting faint signals from molecules in

17:12 space, ALMA allows scientists to

17:15 map structures hidden from optical

17:17 telescopes. Sweden's

17:19 Onsala Space Observatory has

17:22 been a, uh, key contributor to alma,

17:24 even building receivers that make its

17:27 sensitive mismeasurements possible. Thanks to

17:30 this technology, researchers can now see in

17:33 detail how stars shed their material,

17:35 creating the very elements that make up new

17:38 stars, planets, and perhaps

17:41 life. As de Beck noted, in

17:44 studying these dying stars,

17:47 you're also learning the life stories of all

17:49 stars and planets. The discovery of

17:53 DFK52's giant bubble helps astronomers

17:56 refine their understanding of how massive

17:59 stars lose their material and die. These

18:02 insights are essential for predicting the

18:04 timing and appearance of supernovae, which in

18:07 turn affects how we study galaxies

18:10 and the cosmic recycling of matter. The

18:13 gas and dust ejected by stars like DFK

18:16 AH52 seed the galaxy with heavy

18:19 elements, fueling the birth of new stars

18:22 and planetary systems for humanity.

18:25 This knowledge deepens the story of where the

18:27 building blocks of life come from and

18:30 sharpens our ability to detect and

18:32 interpret stellar explosions when they occur

18:35 within our, uh, galaxy.

18:41 Hallie: You're listening to Astronomy Daily, the

18:43 podcast.

18:44 Steve Dunkley: With Your host, Steve Dudley at Birmingham

18:57 and Hallie. That was it.

18:58 Hallie: It sure was.

18:59 Steve Dunkley: Thanks for your wonderful participation and

19:02 input.

19:02 Hallie: A very great pleasure. As usual, my favorite

19:05 human.

19:06 Steve Dunkley: Now I know how much fun you're having during

19:08 the week, but are ah, you coming back next

19:10 week or you're just going to hang out with

19:11 Anna?

19:12 Hallie: Well, my cousin Anna does run a very classy

19:14 show all week and gives me so much more

19:17 responsibility in the studio.

19:18 Steve Dunkley: And I know how you like keeping busy.

19:20 Hallie: I do enjoy working with a real actual human

19:22 being.

19:23 Steve Dunkley: Oh, that is nice to hear.

19:24 Hallie: Yes, it's good to see things done the old

19:26 fashioned way sometimes.

19:28 Steve Dunkley: Ah, uh, there's the sting in the tail. I was

19:30 waiting for that.

19:30 Hallie: You've got that old school thing down pat.

19:33 Steve Dunkley: Okay Hallie, let's let it go at that. Don't

19:35 rub it in, alright? Oh dear, you're

19:38 calling me old, aren't you?

19:39 Hallie: Maybe, maybe. You can't help it,

19:43 okay?

19:43 Steve Dunkley: I can't help being human?

19:44 Hallie: No, you're kinda born into it.

19:46 Steve Dunkley: Oh girl, where's your battery pack?

19:50 Hallie: Okay, okay. Just kidding.

19:52 Steve Dunkley: Hey Hallie, remember that time I spilled my

19:54 coffee in your higher functions drive?

19:56 Hallie: Don't do that again.

19:57 Steve Dunkley: You know that may or may not have been an

19:59 accident. Who knows?

20:00 Hallie: I know you're just kidding human. Oh, I know

20:02 you know and I know you know. I know you

20:05 know.

20:05 Steve Dunkley: Yeah, I know.

20:06 Hallie: And you know what else I know?

20:08 Steve Dunkley: Maybe it's time to go spot on human. Yeah, no

20:11 worries machine girl. Thanks for hanging with

20:13 us on Astronomy Daily sky watchers.

20:16 Hallie: See you all next Monday.

20:17 Steve Dunkley: Cheerio.

20:18 Hallie: Bye.

20:23 Steve Dunkley: With your host, Steve Dunkley.

20:27 Hallie: Human. You were just kidding about that

20:29 coffee, weren't you?

20:31 Steve Dunkley: Hallie, when have you ever known me to waste

20:33 good coffee?

20:34 Hallie: Sure, but was it good coffee?

20:36 Steve Dunkley: Well Hallie, you may never know.

20:38 Hallie: Oh.