Historic ISS Medical Evacuation: Crew Returns Safely + Missing Galaxies & Mars Crisis

0:00 Anna: Hey there, space enthusiasts. Welcome to

0:03 Astronomy Daily, your source for the latest

0:05 news from the cosmos. I'm Anna.

0:07 Avery: And I'm, um, Avery. We've got another packed

0:10 show today with some fascinating storeys from

0:12 both near and far. Anna, uh, what are we

0:15 covering?

0:16 Anna: Well, Avery, we're starting close to home

0:18 with some breaking news from the

0:19 International Space Station. Four astronauts

0:22 just completed the first ever medical

0:24 evacuation from the ISS and

0:26 splashed down safely back on Earth.

0:29 Avery: That's quite significant. We'll also be

0:31 diving, diving into a cosmic mystery about

0:33 missing galaxies. Getting an update on

0:36 NASA's troubled MAVEN spacecraft orbiting

0:39 Mars, and exploring some surprising findings

0:42 about how viruses behave in microgravity.

0:45 Anna: Plus, we'll discuss two newly discovered

0:47 exoplanets that are challenging how we think

0:50 about habitable zones. And we'll wrap up with

0:52 an absolutely stunning new radio image of

0:55 the Milky Way that's revealing hidden

0:57 structures we've never seen before.

1:00 Avery: Lots to get through, so let's jump right in.

1:02 Anna: Alright, Avery, start with Our top storey.

1:05 4 International Space Station crew members

1:08 successfully splashed down in the Pacific

1:10 Ocean off the coast of San Diego early this

1:12 morning, marking a historic first for the

1:15 orbital laboratory.

1:16 Avery: Yeah. This was the ISS's first ever

1:19 medical evacuation in its 26 years of

1:22 continuous operation. The crew members

1:24 included American astronauts Mike Fink and

1:27 Zina Cardman, Russian cosmonaut Oleg

1:30 Plutonov and Japanese astronaut Kimiya

1:33 Yui.

1:34 Anna: The capsule touched down at 12:41 Eastern

1:37 Time after spending five months in space.

1:40 Now, NASA has been pretty tight lipped about

1:42 the specific medical issue that prompted this

1:44 early return, which is understandable given

1:47 privacy concerns.

1:49 Avery: Right. What they have said is that the

1:51 affected crew member was and continues to be

1:53 in stable condition. Mike Fink, who was the

1:56 pilot for SpaceX Crew 11, posted on

1:59 social media earlier this week, reassuring

2:01 everyone that the crew is okay and that this

2:04 was a deliberate decision to allow proper

2:06 medical evaluations on the ground. Where full

2:08 diagnostic capabilities exist, that makes

2:11 sense.

2:12 Anna: James Polk, NASA's chief health and Medical

2:14 Officer, mentioned there was a lingering risk

2:17 and uncertainty about the diagnosis that led

2:19 to the decision to bring the crew back

2:21 earlier than originally scheduled. They were

2:24 supposed to stay until mid February.

2:26 Avery: It's worth noting that three other crew

2:28 members remained on the iss. American

2:31 astronaut Chris Williams and Russian

2:33 cosmonauts Sergey Kud Sverchkov and Sergey

2:36 Mikhashev arrived, uh, at the State Station

2:38 in November aboard a Russian Soyuz

2:40 spacecraft. So station operations continue

2:42 normally.

2:43 Anna: This really highlights the importance of

2:45 having trained medical protocols in place.

2:47 The evacuated crew members had been trained

2:50 to handle unexpected medical situations. And

2:53 according to senior NASA official Amit

2:55 Kshatriya, they handled everything extremely

2:58 well.

2:58 Avery: Absolutely. And this serves as a good

3:00 reminder that despite all the incredible

3:03 engineering and planning that goes into

3:05 spaceflight, we're still dealing with human

3:07 bodies. In an extreme environment, things

3:10 can and do happen.

3:11 Anna: Well, we're glad everyone is safe and

3:13 receiving the care they need back on Earth.

3:16 Avery: Alright, Anna.

3:17 Our next storey takes us much further out

3:19 into space and much further back in time.

3:22 For years, astronomers have assumed that if

3:24 they looked hard enough into the deep cosmos,

3:26 they'd find an almost infinite supply of

3:29 tiny, dim galaxies hiding in the darkness.

3:32 Anna: Right. The prevailing theory has been that

3:34 the smaller the galaxy, the more of them

3:36 there should be. It's kind of like a pyramid

3:38 where you have a few massive galaxies at the

3:41 top and exponentially more small ones as you

3:44 go down.

3:44 Avery: Exactly. But a new study led by Xu

3:47 Heng Ma from the University of Wisconsin is

3:50 challenging that assumption. Using data from

3:52 the James Webb Space Telescope's Uncover

3:55 programme, the team looked through a massive

3:57 galaxy cluster called Abel 2744,

4:00 which acts as a natural gravitational lens.

4:03 Anna: Oh, that's clever. The gravity from this

4:06 cluster literally warps space time and acts

4:09 like a cosmic magnifying glass, right?

4:11 Avery: Precisely. It bends and brightens light from

4:14 more distant objects, allowing us to see

4:16 galaxies from the epoch of reionization,

4:19 roughly 12 to 13 billion years ago.

4:22 This was a transformative era, when the first

4:24 stars and galaxies were flooding the universe

4:27 with ultraviolet light.

4:29 Anna: So what did they find that was so surprising?

4:32 Avery: Well, when researchers count galaxies of

4:34 different brightnesses, they normally use

4:36 what's called a luminosity function. It's

4:39 basically a cosmic bar chart showing how many

4:41 bright versus dim galaxies exist. And

4:44 for study after study, the chart kept going

4:47 in one direction. More small think

4:49 galaxies than bigger, brighter ones.

4:52 Anna: But that's not what they found this time.

4:55 Avery: Nope. Instead of continuing to climb, the

4:57 numbers peaked and then started to drop off.

5:00 They're calling this faint end suppression,

5:03 which means that below a certain brightness,

5:05 the population of galaxies actually starts to

5:07 thin out.

5:08 Anna: So where did all these tiny galaxies go?

5:11 Did they just disappear?

5:13 Avery: In a sense, yes. The study suggests it's a

5:16 case of cosmic bullying. In the early

5:18 universe, the intense radiation from the

5:21 first big stars could have heated up the

5:23 surrounding gas so much that small,

5:26 low mass galaxies couldn't hold onto it.

5:28 Without gas, they couldn't form new stars.

5:31 And without stars, they stayed dark,

5:33 essentially becoming cosmic ghosts.

5:36 Anna: That's fascinating, but it also creates a

5:39 problem, doesn't it? I thought these tiny

5:41 galaxies were supposed to be the main drivers

5:43 of reionization.

5:45 Avery: You're absolutely right. This finding

5:47 suggests we might need to rethink our models.

5:49 If these ultra faint galaxies are missing,

5:52 they can't be the ones doing all the heavy

5:54 lifting during reionization. We might need to

5:57 look at slightly bigger, more established

5:59 galaxies to explain how the universe became

6:01 transparent.

6:02 Anna: This is why I love space science. Every

6:05 answer creates 10 new questions.

6:07 Avery: Couldn't agree more. And they'll need more

6:09 data from JWST in upcoming surveys to

6:12 see if this is a universal pattern or just a

6:15 quirk of this particular region of space.

6:18 Anna: Okay, Avery, let's head to Mars now for an

6:20 update on NASA's MAVN spacecraft.

6:23 And unfortunately, it's not good news.

6:26 Avery: No, it's not. NASA officials are now

6:29 saying it's very unlikely they'll be able to

6:31 recover the Mars Atmosphere and Volatile

6:33 Evolution orbiter, which has been silenced

6:35 since December 6th.

6:37 Anna: Maven has been orbiting Mars since September

6:40 2014, studying the planet's upper

6:42 atmosphere and how solar wind strips it away.

6:45 It's also served as a crucial communications

6:47 relay between Mars rovers and Earth.

6:50 Avery: Right. The spacecraft was supposed to pass

6:52 behind Mars as seen from Earth, A routine

6:54 occurrence. But when it emerged, NASA's Deep

6:57 Space Network didn't observe any signal. That

7:00 was over a month ago now.

7:02 Anna: And the telemetry they did manage to recover

7:04 from December 6th wasn't encouraging, was it?

7:08 Avery: Not at all. Analysis of a brief fragment

7:10 of tracking data From a radio science

7:12 experiment indicated the spacecraft was

7:15 tumbling and no longer in its planned orbit.

7:17 That's a really bad sign, because if the

7:19 spacecraft is tumbling, Its antennas aren't

7:22 pointing toward Earth, which makes

7:23 communication basically impossible.

7:26 Anna: They even tried using the Curiosity rover's

7:28 camera to take pictures of MAVEN as it passed

7:30 overhead, assuming it was still in its

7:33 expected orbit. But they didn't detect it.

7:36 Avery: Yeah, on December 16th and 20th.

7:38 The fact that they couldn't spot it suggests

7:40 its orbit has indeed changed significantly.

7:43 Louise Proctor, director of NASA's Planetary

7:46 Science Division, Said it plainly during a

7:48 meeting earlier this week. We will start

7:50 looking again, but at this point, it's

7:52 looking very unlikely that we are going to be

7:54 able to recover the spacecraft.

7:56 Anna: The timing has been particularly challenging,

7:59 too, hasn't it?

8:00 Avery: Absolutely. Mars went into solar

8:03 conjunction on December 29, which is when

8:05 Mars and Earth are on opposite sides of the

8:07 sun. During this period, the sun

8:10 interferes with radio communications, so NASA

8:13 paused all communications with Mars missions.

8:15 That blackout period just ended on January

8:18 16th. So they can resume attempts, but the

8:21 outlook is grim.

8:21 Anna: Um, the good news is that Maven isn't the

8:24 only communications relay at Mars, right?

8:27 Avery: That's correct. Proctor mentioned that other

8:29 orbiters like Mars Reconnaissance Orbiter and

8:31 Mars Odyssey can pick up the slack. She said

8:34 Maven was not a major part of the Mars relay

8:37 network and they're taking steps to ensure

8:39 they can still retrieve data from rovers on

8:41 the surface.

8:42 Anna: Dill, it's sad to potentially lose a

8:44 spacecraft that's been so productive for over

8:46 a decade.

8:47 Avery: Definitely. Maven has made groundbreaking

8:49 discoveries about Mars atmospheric loss and

8:52 even observed an interstellar object called

8:55 3i ATLS late last year.

8:58 Its contributions to planetary science have

9:00 been immense.

9:02 Anna: Our next storey is taking us back to the

9:04 International Space Station, but this time

9:06 we're looking at some much smaller

9:08 inhabitants. Bacteria and the viruses that

9:10 infect them.

9:11 Avery: Oh, this is fascinating research. A new

9:14 study from the University of Wisconsin,

9:16 Madison used E. Coli bacteria and a

9:19 virus called bacteriophage T7

9:22 to study how microgravity affects the

9:24 evolutionary relationship between viruses and

9:27 their hosts.

9:28 Anna: Though they sent bacteria and viruses to

9:30 space.

9:31 Avery: Exactly. They prepared parallel sets of E.

9:34 Coli cultures infected with T7. One

9:37 set stayed on Earth as a control and the

9:39 other went to the ISS to experience

9:41 microgravity. Then they compared what

9:44 happened to both.

9:44 Anna: Groups and I'm, um, guessing things didn't

9:47 play out the same way in both environments.

9:49 Avery: You guessed right. The analysis showed that

9:52 T7 infection still occurred on the ISS,

9:55 but it only proceeded after an initial delay.

9:58 So spaceflight appears to slow down the early

10:01 stages of virus host encounters without

10:03 completely blocking infection.

10:05 Anna: That's interesting on its own, but I imagine

10:08 they dug deeper.

10:09 Avery: They did. They performed whole genome

10:11 sequencing and found that both the viruses

10:14 and bacteria accumulated distinctive patterns

10:17 of mutations in space compared to their

10:19 counterparts on Earth. The viruses evolved

10:22 specific changes that appear to improve their

10:24 ability to bind to and infect bacterial

10:26 cells.

10:27 Anna: And what about the bacteria? Were they just

10:29 sitting drugs?

10:30 Avery: Not at all. The space flown E. Coli

10:33 populations acquired mutations that may

10:35 strengthen their defences against virus

10:37 attack and enhance their chances of surviving

10:39 in near weightless conditions. It's like they

10:42 were engaged in an evolutionary arms race,

10:44 but the rules of the race were different in

10:46 space.

10:47 Anna: So microgravity is actually changing

10:50 how evolution works?

10:51 Avery: In a sense, yes. The study shows that

10:54 spaceflight not only changes the physiology

10:57 of microbes, but also the physical

10:59 environment in which viruses and bacteria

11:01 encounter each other. This alters the rules

11:04 of their evolutionary interaction.

11:06 Anna: Okay, but beyond the pure science

11:08 fascination, does this have any practical

11:10 applications?

11:12 Avery: Absolutely. Here's where it gets really

11:14 cool. They conducted follow up experiments on

11:17 Earth and found that the microgravity

11:19 associated mutations actually increase

11:22 the virus's activity against disease causing

11:24 E. Coli strains that normally resist

11:27 T7 strains that are implicated in

11:29 urinary tract infections and are often drug

11:32 resistant.

11:33 Anna: So by studying viral evolution in space, we

11:36 might actually discover new ways to fight

11:38 antibiotic resistant bacteria here on Earth.

11:41 Avery: That's exactly what the researchers are

11:43 suggesting. According to the authors, these

11:46 space adapted viruses can be harnessed to

11:48 engineer improved bacteriophages for use in

11:51 human health applications.

11:53 Anna: That's incredible. The International Space

11:55 Station continues to prove its worth as a

11:57 unique research platform.

11:59 Avery: Will do for a little while yet.

12:01 Anna: Alright, Avery, let's travel to some distant

12:04 star systems.

12:05 Now, astronomers have discovered two

12:08 new exoplanets that are prompting scientists

12:10 to rethink how we define habitable zones.

12:14 Avery: Yeah, this is really interesting work. The

12:16 research introduces the concept of a

12:18 temperate zone, which is broader than the

12:21 traditional habitable zone we usually talk

12:23 about.

12:23 Anna: Can you explain the difference? I think a lot

12:26 of people assume habitable zone and

12:28 temperate, um, mean the same thing.

12:30 Avery: Good question. The traditional habitable zone

12:33 is pretty narrowly defined. It's the distance

12:36 range from a star where liquid water could

12:38 exist on a planet's surface. But this new

12:41 research led by Madison Scott from the

12:43 University of Birmingham and Georgina

12:45 Dransfield from the University of Oxford,

12:47 expands that to include what they call the

12:50 temperate zone.

12:51 Anna: And how is that defined?

12:53 Avery: The temperate zone is defined by something

12:55 called insolation flux, which describes the

12:58 amount of solar energy reaching a planet's

13:00 surface. They're using a range between about

13:03 136 watts per square metre and

13:06 6805 watts per square metre.

13:09 Earth receives about

13:10 1,361 watts per square metre.

13:13 Just for reference.

13:14 Anna: So it's much broader than the conservative

13:17 habitable zone.

13:18 Avery: Exactly. The point is to identify planets

13:21 that receive moderate levels of stellar

13:23 radiation. They might not be perfect for life

13:26 as we know it, but they're worth studying

13:28 because as our understanding of habitability

13:30 evolves, some of these planets might turn out

13:32 to be more interesting than we initially

13:34 thought.

13:35 Anna: So, uh, what are these two new planets?

13:37 Avery: The first is TOI 6716

13:40 b, which is roughly Earth, sized between

13:43 0.91 and 1.05

13:46 Earth radii and most likely rocky.

13:49 The second is TOI 7384

13:51 b, which is a sub Neptune measuring

13:54 about 3.37 to

13:56 3.77 Earth radi. This one

13:59 probably has a rocky core with a thick

14:01 hydrogen and helium envelope.

14:03 Anna: And they're both orbiting red dwarf

14:06 stars.

14:07 Avery: Correct. They're orbiting what are called mid

14:09 to late type M dwarfs, which are small, dim,

14:12 cool stars. These types of stars are really

14:15 important for this kind of research because

14:16 temperate planets orbiting them are much more

14:19 likely to transit in front of their stars

14:21 from our point of view, making them easier to

14:23 detect and study.

14:25 Anna: So the goal is to build up a catalogue of

14:27 planets that we can actually study in detail.

14:30 Avery: Exactly.

14:31 TOI6716B has a

14:34 predicted transmission spectroscopy metric

14:37 similar to the famous Trappist 1 planets,

14:39 which makes it a good candidate for JWST

14:42 observations if it has retained its

14:44 atmosphere. The researchers conclude that

14:46 these discoveries show the power of combining

14:49 test data with ground based observations to

14:51 build a catalogue of temperate planets for

14:53 atmospheric studies in the coming decade.

14:56 Anna: It's exciting to think we're moving beyond

14:58 just counting exoplanets to actually being

15:01 able to study their atmospheres in detail.

15:03 Avery: And for our final storey today, we're coming

15:06 back home to our own galaxy.

15:08 Astronomers in Australia have just released

15:10 the most detailed low frequency radio image

15:12 of the Milky Way ever produced.

15:15 Anna: This image is absolutely stunning.

15:18 It was captured by the Murchison Wildfield

15:20 Telescope in Western Australia and reveals

15:23 thousands of structures across the galaxy's

15:25 southern sky that we've never seen in this

15:28 kind of detail before.

15:30 Avery: And the numbers behind this are pretty

15:31 impressive. It took over 1 million CPU

15:34 hours to process the data, which was

15:36 collected across 141 nights between

15:39 2013 and 2020.

15:41 Anna: And this isn't just a prettier version of

15:44 something we already had. Right. This is

15:46 genuinely new science.

15:48 Avery: Absolutely. According to the International

15:50 Centre for Radio Astronomy Research, this

15:53 updated release from the GLEAM X survey

15:56 delivers twice the resolution and ten times

15:58 the sensitivity of earlier efforts. Plus it

16:01 covers twice as much of the sky.

16:03 Anna: What kinds of things can we see in this

16:05 image?

16:06 Avery: Well, Silvia Montovani, a, uh, PhD student

16:09 at Curtin University who led the project,

16:11 explains you can clearly identify remnants of

16:14 exploded stars represented by large red

16:17 circles in the image. The smaller blue

16:19 regions indicate stellar nurseries where new

16:22 stars are actively forming.

16:24 Anna: So it's showing us both the birth and death

16:27 of stars.

16:28 Avery: Exactly. One of the major focuses of this

16:31 survey is finding supernova remnants, which

16:33 are notoriously difficult to spot in the

16:35 cluttered background of the Milky Way.

16:38 Hundreds are already catalogued, but

16:40 astronomers believe thousands more are still

16:42 hidden. With this new level of resolution,

16:45 those cosmic scars from ancient stellar

16:47 explosions are easier to identify.

16:50 Anna: The image also helps with pulsar studies,

16:52 doesn't it?

16:53 Avery: Yes. Measuring pulsar brightness across

16:55 different radio bands could improve our

16:57 understanding of how these spinning neutron

17:00 stars function and where they live in the

17:02 galaxy. The survey has catalogued over

17:04 98,000 radio sources in total.

17:07 Anna: That's an incredible number. And I read that

17:10 this is setting the stage for an even more

17:12 powerful telescope.

17:14 Avery: Right. The Murchison Wildfield Array will

17:16 eventually be surpassed by the SKA Low Array,

17:19 which is currently under construction in the

17:21 same region of Western Australia. Once the

17:24 SKA observatory is operational, it'll deliver

17:26 even sharper and deeper views of the

17:28 universe.

17:29 Anna: But for now, we have this remarkable

17:31 foundation. Associate Professor Natasha

17:34 Hurley Walker, who leads the GLEAM X survey,

17:37 called this an exciting milestone in

17:39 astronomy, since no low frequency radio

17:42 image of the entire southern galactic plane

17:44 has been published before.

17:46 Avery: And it's not just about the Milky Way. The

17:48 catalogue includes distant galaxies as well.

17:51 So it's a dense, glowing map of our cosmic

17:53 neighbourhood that future generations of

17:55 astronomers will use, refine and expand upon.

17:59 Anna: Well, that wraps up today's episode of

18:01 Astronomy Daily. We covered quite a bit of

18:03 ground today, from the first medical

18:05 evacuation from the ISS to missing dwarf

18:08 galaxies, a, uh, troubled Mars orbiter,

18:11 viruses evolving in space, newly discovered

18:14 exoplanets, and a spectacular new view of our

18:16 home galaxy.

18:18 Avery: It really shows the incredible breadth of

18:20 space science happening right now. Whether

18:22 it's 300 miles above our heads on the ISS,

18:25 millions of miles away at Mars, or billions

18:28 of light years away in the early universe,

18:30 there's always something new to discover.

18:32 Anna: Thanks so much for joining us today. If you

18:35 enjoyed the show, please subscribe and leave

18:37 us a review. It really helps other space

18:39 enthusiasts find us.

18:41 Avery: And if you have any questions or topics you'd

18:43 like us to cover, reach out to us on social

18:45 media. You'll find us on all the major

18:47 platforms. Just search for AstroDaily Pod.

18:50 We love hearing from our listeners.

18:51 Anna: Until next time, keep looking up Clear

18:54 skies, Everyone.

19:07 Storeys.