Gravitational Wave Breakthroughs, Exoplanet Water Content Surprises, and Gilmour Space's Launch Journey

0:00 Anna: Welcome to Astronomy Daily, your essential

0:02 guide to the cosmos. I'm Anna, ready to

0:05 explore the latest celestial happenings.

0:07 Avery: And I'm Avery joining you with today's

0:09 headlines. We have some truly fascinating

0:12 stories lined up, from groundbreaking new

0:15 methods for detecting gravitational waves to

0:18 surprising discoveries about the water

0:20 content of distant exoplanets.

0:22 Anna: Indeed, we'll also cover a recent very close

0:25 asteroid flyby that you might have missed.

0:27 And get an update on Australia's growing

0:29 space industry with Gilmour Space

0:30 Technologies. It's a packed show, so let's

0:33 get started.

0:34 Our first stop takes us to the cutting edge

0:36 of physics with an exciting new proposal for

0:39 detecting gravitational waves. These ripples

0:42 in space time predicted by Einstein are

0:44 notoriously elusive.

0:46 Avery: That's right, Anna. Physicists, uh, have put

0:48 forward a novel approach to detect what they

0:51 call mid band gravitational waves.

0:54 Operating between

0:56 0.001 and 1 Hz.

0:59 This is a frequency range that existing

1:01 instruments just can't reach effectively.

1:04 Anna: And these mid band waves are crucial because

1:06 they're generated by fascinating systems like

1:09 binary white dwarfs and neutron stars within

1:12 our own Milky Way, as well as the mergers of

1:14 massive black holes.

1:17 What's the secret to this new detection

1:19 method?

1:20 Avery: It relies on optical resonator technology

1:22 originally designed for highly precise

1:24 optical atomic clocks. Dr. Vera

1:27 Guerrera from the University of Birmingham

1:30 highlights that this extends our detection

1:32 capabilities into a new frequency range using

1:34 instruments that are laboratory sized.

1:37 Anna: Laboratory sized? That's quite a departure

1:40 from the massive LIGO and Virgo

1:42 interferometers we're familiar with. This

1:44 could open up a whole new realm of

1:45 possibilities, perhaps even a, uh, global

1:47 network of detectors sooner than anticipated.

1:50 Avery: Precisely. The proposed system uses

1:53 two optical cavities. Essentially mirrors

1:55 bouncing laser light back and forth

1:58 at right angles. While mid band gravitational

2:01 waves don't deform the rigid cavity

2:04 spacer, they subtly alter the phase of the

2:07 light itself. And here's the genius.

2:10 State of the art optical cavities are already

2:12 sensitive enough to pick up these minute

2:15 changes.

2:16 Anna: So it's about exploiting existing super

2:18 sensitive tech for a new purpose. Professor

2:21 Xavier Calmette from the University of Sussex

2:24 added that this detector will allow us to

2:26 test astrophysical models of binary systems,

2:29 explore massive black hole mergers, and even

2:32 search for stochastic backgrounds from the

2:33 early universe. Truly phenomenal

2:36 indeed.

2:37 Avery: While large space based laser interferometers

2:40 like LISA are still about a decade away,

2:43 this optical cavity detector offers an

2:46 immediate and cost effective ground based

2:48 solution for mid band exploration. It

2:51 may be less sensitive, but its immediacy

2:54 makes it a game changer.

2:56 Okay, moving from the ripples of space time

2:59 to the surfaces of distant worlds. We have

3:02 new research challenging our understanding of

3:04 exoplanets, Specifically their water content.

3:08 It seems the universe might be a bit drier

3:10 than we once thought.

3:12 Anna: This is a big one, Avery. For years,

3:14 theories have suggested that many exoplanets,

3:17 particularly sub Neptunes like K2 18B,

3:20 could be entirely covered by deep global

3:22 oceans, Making them potentially habitable.

3:25 These were often dubbed hycean planets, A

3:28 portmanteau of hydrogen and ocean Assuming

3:30 vast amounts of water.

3:32 Avery: Exactly. Sub neptunes are

3:35 larger than Earth, but smaller than Neptune.

3:37 Very common in our galaxy, but absent

3:40 from our own solar system. Many are thought

3:43 to have formed far from their stars beyond

3:45 the snow line, Accumulating ice before

3:48 migrating closer. The prevailing

3:51 idea was that they'd retain a massive water

3:54 envelope.

3:55 Anna: However, this new study, led by Eth Zurich

3:57 and published in the Astrophysical Journal

3:59 Letters, introduces a crucial

4:02 chemical coupling between the planet's

4:04 atmosphere and its interior. Caroline

4:07 Dorn, professor of exoplanets at Eth Zurich,

4:10 put it quite Water on planets is

4:13 much more limited than previously believed.

4:15 Avery: The researcher simulated sub neptunes going

4:18 through a deep hot magma ocean phase with the

4:20 hydrogen gas Shel. Their computer models

4:23 show that during this phase, Chemical

4:25 processes actually destroy most

4:28 H2O water molecules. The

4:30 hydrogen and oxygen atoms attach to metallic

4:33 compounds and disappear into the planet's

4:35 core. The conclusion is any water

4:38 remaining on the surface is likely limited to

4:41 just a few percent at most.

4:43 Anna: That dramatically changes our perspective on

4:45 habitability. If these larger exoplanets are

4:47 far drier than we imagined, it makes the

4:49 search for extraterrestrial life even more

4:52 challenging. Conditions suitable for liquid

4:54 water would likely only exist on smaller

4:56 planets. And even those would require better

4:59 telescopes than James Webb to observe

5:01 clearly.

5:01 Avery: Indeed, and here's a paradox. The

5:04 study suggests that the most water rich

5:07 atmospheres Might actually be found on

5:09 planets formed within the snow line, where

5:11 water wasn't initially accumulated ice,

5:14 but rather produced chemically from hydrogen

5:17 reacting with oxygen from from silicates in

5:20 the magma ocean. It challenges the classic

5:23 link between ice rich formation and water

5:26 rich atmospheres, Emphasizing the role of

5:28 magma ocean atmosphere equilibrium.

5:31 Anna: A truly fascinating insight. So

5:34 rather than being extraordinary, Earth might

5:36 just appear as a typical planet in this new

5:38 model. That in reality, we may not be as

5:41 unique as we previously thought we were. This

5:44 kind of research is critical for refining our

5:46 understanding of planetary formation and the

5:48 conditions for life in the vastness of space

5:50 Space.

5:51 Now let's turn our attention closer to home.

5:53 Though still in space, there was a recent

5:56 celestial visitor that made Quite a close

5:58 approach to Earth, largely unnoticed by the

6:00 general public.

6:02 Avery: That's right, Anna, uh, a small asteroid

6:04 designated 2025 TF

6:07 safely zipped past Earth on Tuesday,

6:09 September 30th at approximately

6:11 8:49pm EDT. Its

6:14 closest approach was roughly 250

6:17 miles, or 400 kilometers above our

6:20 planet's surface.

6:21 Anna: For context, that's about the same altitude

6:23 as the International Space Station. It wasn't

6:25 a record, as asteroid 2020 VT4 flew by

6:28 even closer at 230 miles five years ago.

6:32 But still an incredibly close shave.

6:34 Avery: Indeed. And how big was this particular

6:38 cosmic pebble?

6:40 2025 TF is

6:42 estimated to be about the size of a

6:45 couch, roughly 1.2

6:47 to 2.7 meters in diameter.

6:51 Interestingly, astronomers only spotted

6:54 it a few hours after its closest approach,

6:57 with the Catalina Sky Survey being the

7:00 first to detect it.

7:02 Anna: That's a testament to how challenging these

7:03 smaller objects are to track, especially when

7:06 they come from the sunward direction. Due to

7:09 a government shutdown, NASA hasn't issued a

7:11 formal statement. But data from JPL's

7:14 CNEOS confirmed a uh, nominal distance of

7:16 4,213 miles from Earth's

7:19 center, which corresponds to that

7:21 262 mile altitude over

7:24 Antarctica.

7:25 Avery: While NASA, uh, meticulously monitors larger

7:28 asteroids that could pose a threat, smaller

7:31 rocks like 2025 TF are much harder to

7:34 spot. However, our technology is

7:36 constantly improving and such close safe

7:39 passes are now being detected several times a

7:41 week. It's a reminder of the dynamic nature

7:44 of our solar neighborhood.

7:46 Finally today, let's head down under for an

7:48 update on Australia's burgeoning space

7:50 industry. Gilmour Space Technologies recently

7:53 made its first orbital launch attempt for its

7:56 Ares small launch vehicle.

7:57 Anna: And while that launch attempt on July 30

7:59 lasted only a few seconds, 14 to be precise,

8:02 the company is surprisingly satisfied with

8:04 the outcome and is already planning a return

8:07 to flight next year. CEO Adam

8:10 Gilmour stated that while the rocket was in

8:12 flight for only 14 seconds and its engines

8:15 fired for 23 seconds, it still provided

8:18 invaluable data for their next generation

8:20 rockets.

8:21 Avery: That's certainly a pragmatic outlook after

8:24 what sounds like a less than ideal initial

8:26 launch. Gilmour Space is

8:29 investigating the root cause, suspecting an

8:31 issue that wasn't sufficiently tested under

8:34 conditions closer to actual launch.

8:37 But a significant factor in this first Launch

8:40 was an 18 month delay between shipping the

8:43 rocket and the actual launch.

8:45 Anna: 18 months is an enormous delay for any space

8:47 company. This was largely due to regulatory

8:50 approvals. An astounding 24 permits from the

8:52 Queensland government alone, plus approvals

8:55 from the Australian Space Agency airspace,

8:57 maritime and environmental permits. Adam

9:00 Gilmour openly admitted they hadn't

9:02 adequately resourced those complex regulatory

9:04 processes and regretted not doing more

9:06 testing during those prolonged delays.

9:08 Avery: An incredible bureaucratic hurdle. Despite

9:11 the very short flight, he was quite pleased

9:13 it even managed to get off the pad, Candidly

9:16 referring to it as an old, clunky rocket by

9:19 the time it finally flew. It speaks volumes

9:22 about the challenges of pioneering a new

9:24 space launch capability.

9:26 Anna: Absolutely. However, Gilmour Space

9:29 anticipates a much smoother regulatory

9:31 process for future launches after productive

9:33 meetings with the Australian Space Agency now

9:36 that they've navigated the initial

9:37 complexities, he remains confident in future

9:40 launches, aiming to provide a reliable

9:42 domestic launch capability.

9:44 Avery: And importantly, the company is well

9:46 capitalized, planning to launch again next

9:49 year. This is a crucial step for Australia,

9:51 as Gilmour Space Technologies is a key

9:54 player in fostering a, uh, growing and

9:56 competitive Australian space industry on the

9:59 global stage.

10:01 Anna: What a journey through the cosmos today,

10:03 Avery. From the subtle dance of

10:06 gravitational waves to the surprisingly dry

10:09 interiors of exoplanets, and from a close

10:11 call with an asteroid to the determined

10:13 efforts of Gilmore Space, it's been an

10:15 episode packed with discoveries.

10:18 Avery: Indeed, Anna. It's a vivid reminder of how

10:21 quickly our understanding of the universe is

10:23 evolving. Each new piece of research, whether

10:26 it's about detecting unseen forces or

10:29 rethinking planetary formation, pushes the

10:32 boundaries of human human knowledge a little

10:34 further.

10:34 Anna: And it's not just the scientific discoveries,

10:36 Avery. It's also about the incredible

10:39 ingenuity in how we pursue these discoveries.

10:41 From laboratory sized gravitational wave

10:44 detectors to navigating complex regulatory

10:47 landscapes for space launches, the

10:50 human spirit of exploration is as vast as the

10:52 cosmos itself.

10:54 Avery: That's beautifully put, Anna. Ah, this

10:56 continuous push for knowledge, coupled with

10:59 innovation in technology and even policy,

11:02 truly underscores our inherent drive to

11:05 understand our place in the universe. It's a

11:08 journey that constantly redefines what's

11:10 possible.

11:11 Anna: And that wraps up another episode of

11:12 Astronomy Daily. Thank you for joining us on

11:15 this exploration of the universe.

11:17 Avery: We hope you enjoyed delving into these

11:18 stories with us. Don't forget to subscribe

11:20 wherever you get your podcasts to stay

11:22 updated with all the latest from beyond our

11:24 blue planet. Until next time, keep looking up