European Launch Ambitions, Starquake Mysteries, and the Quest for Hidden Stars

0:00 Avery: Hello, and welcome to Astronomy Daily, the

0:02 podcast that brings you the latest news from

0:05 across the cosmos. I'm Avery.

0:07 Anna: And I'm Anna. It's great to be with you.

0:10 Today's agenda covers a lot, from Europe's

0:12 new ambitions in space launch to the strange

0:15 secrets of starquakes near black holes.

0:18 Avery: That's right. We'll also be diving into the

0:21 very nature of time itself, searching for

0:24 hidden stars that might host intelligent

0:26 life, and looking at a new mission to monitor

0:28 the dangers of living on the Moon. So

0:31 let's get started.

0:32 Anna: First up, there's big news from the European

0:35 Space Agency. It looks like they're getting

0:38 very serious about fostering a commercial

0:40 launch market.

0:41 Avery: They certainly are. ESA member states have

0:44 committed over 900 million euros to the

0:47 European Launcher Challenge. That's more than

0:49 double what was anticipated.

0:50 Anna: And what's interesting here is the strategy.

0:53 This isn't about esa, uh, directly funding

0:55 the development of a new rocket. Instead,

0:58 they're acting more like a customer,

1:00 promising to purchase launch services and co

1:03 fund upgrades for private companies.

1:05 Avery: Right. It's the shift from being the builder

1:07 to being an anchor client. It's a model that

1:10 has worked very well for NASA with companies

1:12 like SpaceX. It stimulates competition and

1:15 innovation.

1:16 Anna: Exactly. There's a whole list of companies

1:19 shortlisted for this, including Isar

1:21 Aerospace Rocket Factory, Augsburg

1:24 and PLD Space, among others. Rock

1:27 seeing major contributions from countries

1:29 like Germany, Spain and the uk.

1:32 Avery: So what's the timeline for this? When can we

1:35 expect to see these new launch services in

1:37 action?

1:38 Anna: The plan is to sign framework agreements in

1:40 2026 with the goal of seeing launch

1:43 system demonstrations by 2027.

1:46 If all goes well, we should see actual

1:48 missions being flown under this program by

1:51 2030. It's a major step towards

1:53 European autonomy and space access.

1:56 Avery: From launching rockets to listening to

1:59 stars.

1:59 Our next story is truly fascinating.

2:02 Scientists are using starquakes to uncover

2:05 the secrets of dormant black holes. And it's

2:08 rewriting what we thought we knew.

2:10 Anna: Starquakes. So you mean

2:12 asteroseismology, studying the oscillations

2:15 of stars?

2:16 Avery: Precisely. The study focused on two

2:19 systems, Gaia BH2 and

2:21 Gaia BH3. Each has a

2:24 red giant star orbiting a quiet black hole.

2:27 In the Gaia BH2 system. The

2:30 starquakes revealed a puzzle. The star

2:33 appears young, but its chemical composition

2:35 says it's old.

2:37 Anna: That's a contradiction. How did they explain

2:39 that?

2:40 Avery: The leading theory is that the red giant is

2:42 actually the product of two stars that merged

2:45 into one. This would explain its unusually

2:48 fast spin rate as well. So it had a dramatic

2:51 life even before it got captured by the black

2:53 hole.

2:54 Anna: Incredible. And what about the other system,

2:57 Gaia BH3?

2:58 Avery: That one presented a different kind of

3:00 mystery. The red giant in that system is

3:03 ancient and what we call metal poor.

3:06 According to our models, it should be showing

3:09 star quicks, but it isn't. It's completely

3:11 silent.

3:12 Anna: So our understanding of how these old

3:15 stars behave might be wrong.

3:17 Avery: It suggests that, yes, the research is

3:20 a fantastic example of how studying these

3:23 companion stars can refine how we measure

3:26 black hole masses and reveal the complex,

3:29 violent histories these systems can have.

3:32 Anna: Well, from the complex history of

3:34 stars to the complex nature of time

3:37 itself. This is a topic that has baffled

3:40 physicists and philosophers for centuries.

3:42 And as St. Augustine famously said, we know

3:45 what time is until someone asks us to

3:48 explain it.

3:49 Avery: It's one of the ultimate questions. And a lot

3:51 of the confusion, according to some

3:53 physicists, comes from mixing up two

3:56 different existence

3:59 and occurrence.

4:00 Anna: Okay, break that down for us.

4:02 Avery: The universe as a physical object exists.

4:05 But events within the universe don't exist

4:08 in the same way. They happen or they

4:11 occur. The past isn't a place that still

4:14 exists, and the future isn't a place that's

4:17 waiting for us. They are just records and

4:19 probabilities of occurrences.

4:21 Anna: That makes sense. So this helps clarify

4:24 some old philosophical arguments.

4:26 Avery: It does. Take the ancient Greek philosopher

4:29 Parmenides, who argued that since we can talk

4:32 about the past and future, they must exist.

4:35 This new perspective says that's a fallacy.

4:38 Based on that core confusion. The same goes

4:41 for how we often interpret Einstein's concept

4:43 of spacetime.

4:44 Anna: Right. People often imagine spacetime as

4:47 a physical block universe that you could

4:50 theoretically travel through.

4:52 Avery: Exactly. But it's more useful to think of

4:54 spacetime as a map of events. The map is a

4:57 real useful model, but it's not the

5:00 territory. The map of your city exists, but

5:02 you can't live in the map. By

5:05 cleanly separating the existence of the

5:07 universe from the occurrence of events, the

5:10 so called mystery of time becomes much less

5:12 mysterious.

5:14 Anna: Speaking of searching for things, let's turn

5:16 our attention to the search for

5:18 extraterrestrial intelligence, or seti.

5:22 A, uh, new study suggests we can make our

5:24 search much more effective by accounting for

5:27 stars that we've been ignoring.

5:29 Avery: Hidden stars. How can a star be hidden?

5:32 Anna: It's not that they're physically hidden, but

5:34 they're not the primary targets of our

5:37 surveys. Think about it. When a radio

5:39 telescope points at a specific star, its

5:42 field of view is much wider. It

5:45 inevitably captures data from countless other

5:47 stars in the background and foreground. The

5:50 study calls this stellar bycatch.

5:53 Avery: Ah, uh, I see. So we have all this data

5:56 on stars we weren't even intentionally

5:58 looking at.

5:59 Anna: Precisely. The challenge is knowing which

6:02 stars are in that bycatch. To to solve

6:04 this, scientists are using something called

6:06 the Besanc Galactic model. It

6:09 simulates our galaxy's star populations,

6:12 allowing them to predict which hidden stars

6:14 are likely in a telescope's field of view at

6:17 any given time.

6:18 Avery: So this vastly expands the number of stars

6:21 we're monitoring for technosignatures without

6:23 needing any new observations or equipment.

6:26 Anna: Yes, and it also helps remove human

6:29 bias from target selection. Projects like

6:32 Breakthrough Listen can now apply this method

6:34 to get a much more comprehensive survey of

6:37 our galaxy. It's a very clever way to

6:39 maximize the scientific return from the data

6:42 we're already collecting.

6:44 Avery: For our final story, we're coming back a

6:46 little closer to home to the Moon. As

6:49 nations like China and the US make serious

6:51 plans for lunar bases, a new mission from

6:54 Hong Kong aims to monitor a constant threat.

6:57 Things falling from the sky.

6:59 Anna: You mean meteoroid impacts? We know they

7:01 happen, but this mission aims to provide the

7:04 first ever continuous monitoring of them from

7:07 lunar orbit.

7:08 Avery: That's right. The mission is called Wessen,

7:10 which means Moon flashes. It's a lunar

7:13 orbiter set to launch by 2028. Its

7:16 primary job will be to watch for the bright

7:18 flashes caused by meteoroids hitting the

7:21 lunar surface.

7:22 Anna: And this data is critical. Without an

7:24 atmosphere to burn them up, even small

7:27 pebbles can hit with the force of a hand

7:29 grenade. These impacts pose a very real

7:32 threat to future lunar infrastructure and

7:34 of course, to astronauts.

7:36 Avery: It's a huge engineering and safety challenge.

7:39 Wesson's data will be particularly valuable

7:41 for China's ambitious plans to establish a

7:44 lunar research station. What's also notable

7:46 is that the telescope for the mission is

7:48 being designed and built in Hong Kong,

7:50 marking a significant step for the city in

7:52 space exploration.

7:53 Anna: It will be a great complement to other

7:55 monitoring efforts like NASA's Earth based

7:58 observations and ESA's proposed

8:01 Lumio mission. To truly understand the

8:03 risks of living on the Moon, we need that

8:06 constant close up view. USAN

8:09 promises to deliver just that.

8:11 Avery: And that's all the time we have for today.

8:13 From commercial rockets to cosmic

8:15 philosophies, we've covered a lot of ground.

8:18 Anna: We hope you enjoyed the journey. Join us next

8:20 time for another edition of, uh, Astronomy

8:23 Daily, where we continue to explore the

8:25 universe one story at a time.

8:27 Avery: Thanks for listening and one quick plug.

8:30 For more space and astronomy news and

8:33 all our back catalog just visit our

8:36 [email protected].

8:40 you can also follow us on social media. Just

8:42 search for AstroDaily Pod on your

8:45 favorite platforms. That's it for me. I'm

8:48 Avery Clear Skies, everyone, and keep looking

8:51 up.