Cosmic Tug-of-War, Mars Orbiter's Stellar Capture, and Black Hole Anomalies

0:01 Avery: Welcome to Astronomy Daily, the podcast that

0:04 brings you the universe one story at a

0:06 time. I'm avery. Give us 10 minutes and

0:09 we'll give you the universe.

0:11 Anna: And I'm, um, Anna. It's great to be with you.

0:14 Avery: Today we're talking about the ultimate fate

0:16 of the universe. Is its expansion slowing

0:19 down. We'll also check in on a Mars orbiter

0:22 that's been moonlighting as an interstellar

0:24 photographer and and get an update on.

0:26 Anna: A scrubbed launch, plus a baffling

0:29 record breaking flare from a distant black

0:31 hole. And a fascinating new paper that

0:34 asks, could alien probes already be

0:37 in our solar system?

0:38 Avery: It's a lot to cover, so let's jump right

0:41 in.

0:41 Anna, start us off with this universe

0:43 altering news.

0:44 Anna: Let's do it. The main headline is that our

0:47 universe's expansion might be slowing down.

0:50 This feels counterintuitive to what we've

0:52 understood for decades.

0:54 Avery: It really does.

0:55 Anna: For a long time, the standard model of

0:57 cosmology, which we call lambda cdm,

1:00 has been built on the idea that the

1:02 universe's expansion is accelerating, driven

1:05 by a mysterious force called dark energy.

1:08 Avery: Right, the cosmological constant, the

1:10 lambda in lambda cdm.

1:13 Anna: Exactly. It's been treated as a constant,

1:15 unchanging force pushing everything apart.

1:18 But new research analyzing data from various

1:21 cosmic probes and telescopes suggests that

1:24 that dark energy might not be constant at

1:26 all. It might be evolving and even

1:29 weakening over time.

1:31 Avery: Evolving? What does that mean for a

1:33 fundamental force of the universe?

1:35 Anna: It means that dark energy could be something

1:37 more dynamic, what some physicists call

1:40 quintessence. Instead of being a static

1:43 property of spacetime, it could be a field

1:45 that changes over cosmic history. This new

1:48 evidence suggests its repulsive force might

1:50 be decaying.

1:52 Avery: Wow. So if the outward push is getting

1:54 weaker, what happens then?

1:56 Anna: Well, that's the most dramatic part of this

1:59 story. If dark energy continues to weaken,

2:02 the fundamental force of gravity, which is

2:04 always pulling inward, could eventually win

2:07 the cosmic tug of war.

2:08 Avery: And that leads to the Big Crunch?

2:11 Anna: Potentially, yes. Instead of expanding

2:14 forever into a cold, dark big freeze,

2:17 the the universe's expansion would slow,

2:19 halt, and then reverse.

2:22 Galaxies would start rushing back towards

2:24 each other, eventually collapsing into an

2:27 incredibly hot, dense singularity.

2:30 Much like the state before the Big Bang.

2:32 Avery: It's a mind bending possibility. So is the

2:35 Big Crunch our new official destiny?

2:37 Anna: Not just yet. This research is still

2:40 challenging the prevailing model, and a lot

2:43 more data is needed to confirm it. But it's a

2:45 huge development that has cosmologists and

2:48 everywhere buzzing. It just reminds us that

2:50 the universe is still full of Profound

2:52 mysteries.

2:53 Avery: Absolutely.

2:54 Well, let's pull our focus from the edge of

2:56 the universe back into our own solar system.

2:59 China's Tianwan 1 orbiter has sent back

3:02 some incredible new images.

3:03 Anna: That's right. While its primary mission at

3:05 Mars is complete, Tianwen1 is in an

3:08 extended mission phase. And it has

3:10 accomplished something remarkable. It managed

3:13 to capture detailed images of an interstellar

3:16 object known as 3i Atlas.

3:19 Avery: An interstellar object. So a visitor from

3:22 another solar system like Oumuamua.

3:25 Anna: Precisely. These objects are incredibly

3:28 rare and difficult to observe. Getting high

3:31 resolution images of one from a spacecraft

3:33 already in deep space is a major

3:36 technical achievement. It gives us a close up

3:38 look at a building block from another solar

3:41 system.

3:41 Avery: What can we learn from it?

3:43 Anna: The data helps us understand its composition,

3:46 shape and rotation, which tells us about the

3:49 conditions in the planetary system wherein

3:51 formed. It's also fantastic

3:54 practice. Practice for what? For their

3:57 next big mission, Pianwen 2. That

3:59 mission is designed to visit a near Earth

4:02 asteroid, collect samples and return them to

4:04 Earth. Successfully tracking and imaging

4:07 a fast moving distant object like

4:10 3i ATLAS proves their

4:12 capabilities and provides valuable data for

4:15 planning that ambitious sacrifice sample

4:17 return mission.

4:18 Avery: Very cool.

4:19 Now for a quick update from the launch pad.

4:22 It was a no go for United Launch alliance

4:24 yesterday.

4:25 Anna: Yes, unfortunately the much anticipated

4:28 launch of their Atlas V rocket carrying the

4:30 Viasat 3F2 satellite was

4:33 scrubbed.

4:34 Avery: They called it off late in the countdown. Any

4:37 word on what the issue was?

4:38 Anna: The official reason cited was an issue with

4:41 ground systems equipment. These are complex

4:44 machines and safety is paramount. These. The

4:46 good news is they've already rescheduled the

4:49 launch for the following day.

4:51 Avery: Fingers crossed for a successful liftoff.

4:53 This is an important satellite, right?

4:55 Anna: It is. It's the second of three satellites in

4:58 a constellation designed to provide high

5:00 speed, affordable broadband Internet service

5:02 to most of the globe. So we'll be watching

5:05 closely and wishing them the best on the next

5:07 attempt.

5:08 Avery: Alright, From a launch delay back to the deep

5:10 cosmos, this next story sounds like a real

5:13 head scratcher for astronomers. A

5:15 supermassive black hole has unleashed a flare

5:17 of epic proportions.

5:18 Anna: It really is a puzzle. This flare

5:21 spotted by the Zwicky Transient Facility

5:24 or ztf, is not just bright.

5:27 It's the longest lasting flare we've ever

5:29 seen from a supermassive black hole. It has

5:32 been going on for years and shows no signs of

5:35 stopping.

5:36 Avery: Years? I thought these things were usually,

5:38 well, transient. And that's what the TNZTF

5:41 stands for, right?

5:42 Anna: Exactly. Usually when a star gets too

5:44 close to a supermassive black hol torn

5:47 apart in what we call a tidal disruption

5:49 event that causes a flare that typically

5:52 lasts for a few weeks or months. This event

5:55 is on a completely different timescale.

5:58 Avery: So what do they think is causing it?

5:59 Anna: That's the mystery. The leading theory is

6:02 that it's an exceptionally massive star,

6:05 perhaps a hundred times the mass of our own

6:07 sun, that has been captured and is slowly

6:10 being consumed. But even that doesn't fully

6:13 explain the flare's duration and steady

6:15 brightness.

6:16 Avery: It must be an incredible opportunity for

6:18 research, though.

6:19 Anna: An unprecedented one. Because this black

6:21 hole is so distant, we're seeing it as it was

6:24 in the very early universe. Studying this

6:27 long slow meal gives us a unique window

6:30 into how supermassive black holes grow

6:33 and affect their host galaxies in the cosmic

6:36 dawn.

6:37 Avery: From one mind bending topic to another. Our

6:39 final story sounds like pure science fiction,

6:42 but it's being discussed in a serious

6:44 scientific paper. Are we talking about alien

6:47 probes?

6:47 Anna: We are. Specifically, the paper

6:50 discusses the concept of von Neumann probes.

6:53 These are theoretical self replicating

6:55 robotic probes that could be sent to explore

6:57 a, uh, galaxy.

6:59 Avery: Self replicating? So one probe arrives in a

7:02 new star system, uses local resources to

7:04 build copies of itself, and then those copies

7:07 travel to other star systems?

7:08 Anna: That's the idea. It's an incredibly efficient

7:11 way to explore the vastness of the Milky Way

7:14 on a timescale of millions of years, rather

7:16 than billions. Billions. The new paper makes

7:19 a bold suggestion that if an advanced

7:21 civilization has ever created such probes,

7:24 they could already be here in our own

7:27 solar system.

7:28 Avery: Okay, wow. So where should we be

7:30 looking?

7:31 Anna: The paper proposes we should be actively

7:33 searching for their technosignatures,

7:36 evidence of their technology. And it singles

7:39 out a prime location for the search. Our

7:42 Moon. Why the Moon? Because it's

7:44 a stable, geologically dead world. A

7:47 probe could land there, use lunar resources

7:50 to replicate, and its artifacts could remain

7:53 undisturbed for hundreds of millions of

7:55 years. Unlike Earth, there's no weather or

7:58 geological activity to erase the evidence.

8:01 Avery: So we should be scanning the high resolution

8:03 images we have of the lunar surface for

8:05 anything out of place.

8:08 Anna: Exactly. It's a long shot, of course,

8:11 but the authors argue it's a, uh, search

8:14 worth conducting. Finding even a

8:17 single non terrestrial artifact on the

8:19 Moon would be one of the most profound

8:22 discoveries in human history.

8:25 Avery: And what a profound thought to end on. From

8:27 the fate of the universe and interstellar

8:30 visitors to bizarre black holes and the

8:32 possibility of ancient alien technology on

8:35 our doorstep. What a day in Astronomy.

8:38 Anna: It certainly shows that there is always

8:40 something new to discover, no matter where we

8:43 look. Thanks for joining us today on

8:45 Astronomy Daily.

8:47 Avery: We'll be back tomorrow with more news from

8:49 across the cosmos. Until then, be sure to

8:51 subscribe wherever you get your podcasts so

8:54 you never miss an episode. Clear Skies