Cosmic Connections: Uranus's New Moon, Rogue Planets, and the Devil Comet's Water Mystery

0:00 Anna: Hello and welcome to Astronomy Daily,

0:03 your daily guide to the cosmos, where we.

0:06 Avery: Explore the latest breakthroughs and biggest

0:08 stories from the world of space and

0:10 astronomy. I'm Avery.

0:12 Anna: And I'm Anna. It's great to have you with us.

0:15 We have an absolutely stellar lineup for you

0:17 today.

0:18 Avery: We certainly do. We'll be visiting the

0:20 distant ice giant Uranus, which has a brand

0:23 new moon. We'll also be exploring the lonely

0:26 lives of rogue planets, which it turns out

0:29 might not be so lonely after

0:32 a.

0:32 Anna: Tale of two sibling asteroids that could hold

0:34 clues to the origin of life. And

0:37 we'll be chasing the famous Devil Comet to

0:40 find out if it's responsible for the water in

0:42 our oceans.

0:43 Avery: It's a packed show, so let's jump right in.

0:46 Anna: Our first story takes us out to the seventh

0:48 planet from the sun. The solar system's

0:51 family portrait has a new addition as

0:53 astronomers have officially confirmed the

0:56 discovery of a new moon orbiting Uranus.

0:59 Avery: That is fantastic news. It feels like the

1:02 outer planets are the final frontier of our

1:04 own solar system. It's amazing to think we're

1:07 still finding new members out there. What do

1:09 we know about this newcomer?

1:11 Anna: Well, for one thing, it's incredibly small.

1:13 Current estimates put its diameter, uh, at

1:16 just five miles, or about eight kilometres.

1:18 That makes it a strong contender for the

1:21 title of smallest of Uranus's now 28

1:23 known moons.

1:25 Avery: Five miles, that's miniscule on a planetary

1:27 scale. To put that in perspective, that's

1:30 shorter than running a 10k race. How on Earth

1:32 did they even spot something so tiny so far

1:35 away?

1:36 Anna: With a very powerful telescope and

1:38 a lot of patience. The discovery was made

1:41 using the Magellan telescopes at the Las

1:43 Campanas Observatory in Chile. The first

1:46 sighting was on November 4, 2023.

1:49 But it took further observations to confirm

1:52 its orbit and officially announce it on

1:55 February20.

1:56 Avery: And it's been given one of those classic

1:58 catchy astronomer names, I assume.

2:00 Anna: Of course, for now, it's carrying the

2:03 temporary designation S

2:05 2023 U1. It will likely

2:08 get a more permanent name later,

2:10 traditionally from the works of Shakespeare

2:12 or Alexander Pope. In keeping with Uranus's

2:15 other moons.

2:16 Avery: I'll be waiting to see if it becomes a Juliet

2:18 or a Puck. I also read that its orbit is

2:21 huge. It takes 680 days to

2:24 circle Uranus. That's a long year for such a

2:27 tiny moon.

2:28 Anna: It is indeed. And this find is significant

2:31 because it's the first new Uranian

2:34 moon discovered in more than 20 years. It

2:37 really underscores how much we still have to

2:39 learn about the ice Giants. They're distant,

2:42 dim and difficult to study from Earth.

2:45 Avery: It makes you wonder what else is hiding out

2:47 there in the dark. A tiny body like this was

2:49 probably a captured object from the Kuiper

2:52 Belt, wasn't it? A visitor that got a little

2:54 too close and was pulled into orbit?

2:56 Anna: That's the leading theory. Its distant

2:59 eccentric orbit suggests it wasn't formed

3:01 from the same disc of material as Uranus's

3:04 larger inner moons. It's a relic from the

3:07 early solar system, now a permanent part of

3:10 Uranus's family.

3:11 Avery: Well, from a captured moon to entire

3:13 systems without a sun.

3:15 Our next story is a real mind bender. It's

3:18 about rogue planets and the astonishing

3:20 possibility that they can form their own

3:22 moons.

3:23 Anna: This is truly a revolutionary idea,

3:26 backed by some stunning observations from the

3:28 James Webb Space Telescope. For our

3:31 listeners. Rogue planets, or as

3:34 they're officially called, free floating

3:36 planetary mass objects, are worlds that

3:38 drift through interstellar space completely

3:41 untethered from any star.

3:43 Avery: We used to imagine them as cold, dark and

3:46 solitary objects, but this new research

3:48 suggests that they might be the centre of

3:50 their own little solar systems. JWST

3:53 observed eight of these rogue planets in the

3:56 nearby Orion Nebula.

3:57 Anna: And it didn't just see the planets

3:59 themselves. It saw that they were surrounded

4:02 by discs of gas and dust. What's

4:05 more, the telescope's instruments detected

4:07 the chemical signature of crystalline

4:10 silicates within these discs.

4:12 Avery: And that's important because.

4:14 Anna: Because that's the very same material we

4:17 see in the protoplanetary discs around

4:20 young stars. It's the raw material that

4:23 clumps together to form planets, moons

4:26 and asteroids. Finding it around a

4:28 rogue planet is a huge surprise.

4:31 Avery: Uh, so you're saying these starless planets

4:34 have their own proto moon discs,

4:37 that they're basically acting like miniature

4:39 suns, gravitationally gathering material

4:42 to build their own satellite systems?

4:44 Anna: That's exactly what the evidence points to.

4:48 These discs could and likely will

4:51 coalesce into moons and perhaps even

4:53 ring systems, all orbiting a planet

4:56 that has no star. It creates a whole

4:59 new class of celestial object, a

5:02 rogue planetary system.

5:04 Avery: Wow. That fundamentally challenges our

5:07 models of system formation. We've always put

5:10 a star at the heart of that process. The

5:13 star's gravity and energy were thought to be

5:15 essential.

5:16 Anna: It seems the fundamental physics of accretion

5:19 might be more universal than we thought.

5:22 Gravity is the key ingredient and it

5:24 seems a, uh, planet sized object has enough

5:27 of it to start building a family of its own.

5:30 The galaxy could be teeming with these dark

5:33 wandering systems, completely

5:35 invisible to us until now.

5:38 Avery: From lonely wanderers. Let's come Back closer

5:40 to home for a story about family.

5:43 Two of the most famous asteroids in recent

5:45 memory, Ryugu and Bennu, have been

5:48 confirmed to be siblings.

5:50 Anna: This is the payoff for two of the most

5:53 ambitious sample return missions ever

5:56 attempted. Japan's Hayabusa 2

5:58 mission visited Ryugu and NASA's

6:01 Osiris Rex mission visited Bennu. Both

6:04 successfully brought back pristine samples.

6:07 And now we're seeing the incredible result.

6:10 Avery: Uh, and the results are conclusive. By

6:12 analysing the composition of the return

6:15 samples, scientists have confirmed that both

6:17 of these carbon rich top shaped

6:20 asteroids are fragments of the same

6:23 much larger parent body.

6:25 Anna: So somewhere long ago, a, uh, giant

6:28 asteroid got hit by something else in a

6:30 catastrophic collision and shattered. And

6:33 Ryugu and Bennu are two of the pieces that

6:36 went flying.

6:37 Avery: Precisely. The mineralogy and chemical

6:40 makeup are just too similar for it to be a

6:42 coincidence. But what's really exciting

6:45 isn't just that they're related, but what

6:48 they're made of. This is where it gets really

6:50 interesting for us here on Earth, right?

6:52 Anna: Absolutely. Both samples are rich

6:55 in water bearing clay minerals. That tells us

6:58 their parent body once had a lot of water

7:01 ice. And even more importantly, they

7:04 are packed with a wide variety of organic

7:06 molecules.

7:08 Avery: Amino, um, acids, the building blocks of

7:10 proteins. The very stuff of life.

7:13 Anna: Exactly. This discovery provides

7:16 powerful support for the hypothesis that

7:18 asteroids and comets acted as a

7:21 cosmic delivery service for the early Earth.

7:24 They could have delivered both the water for

7:26 our oceans and the complex organic

7:29 compounds necessary to kickstart life.

7:32 Avery: So when we look at these two sibling

7:33 asteroids, we could be looking at the same

7:36 type of object that gave Earth its

7:38 starter kit for life. It's like finding the

7:41 delivery truck that brought the ingredients

7:43 for the first ever cake.

7:45 Anna: That's a great analogy. It

7:47 reinforces the idea that the ingredients for

7:50 life aren't necessarily rare or unique

7:53 to Earth, but are widespread throughout the

7:56 solar system, just waiting for the right

7:58 conditions.

7:59 Avery: Well, speaking of that cosmic delivery

8:02 service, our final story today zooms

8:04 in on one very specific delivery

8:07 truck, the Devil Comet. And it's

8:10 carrying a very precious cargo.

8:12 Anna: Yes, the Comet, officially named 12

8:15 P. Pons Brooks, has been putting

8:17 on quite a show for astrophotographers.

8:21 But for planetary scientists, the real show

8:23 is what's inside the water vapour it's

8:26 releasing as it nears the sun.

8:29 Avery: Using incredibly sensitive instruments like

8:31 the Atacama Large Millimetre Sub Millimetre

8:34 Array, or ALMA, and

8:36 NASA's Infrared Telescope Facility,

8:39 researchers have been able to analyse that

8:42 water. And they found what many have been

8:44 searching for for decades.

8:46 Anna: They have the water in Comet

8:49 Pons Brooks has an isotopic

8:51 signature that is a near perfect

8:54 match for the water here on Earth.

8:57 Avery: Okay, let's break that down. An

9:00 isotopic signature is like a chemical

9:02 fingerprint. Right. It's about the different

9:05 flavours of hydrogen atoms in the water

9:07 molecules.

9:08 Anna: That's a good way to put it. Specifically,

9:11 scientists measure the ratio of

9:14 deuterium, a heavy version of hydrogen,

9:17 to normal hydrogen. This is

9:20 known as the D to H ratio.

9:23 For a long time, the comets we were able to

9:26 measure had much higher D to H AH

9:28 ratio than Earth's oceans, which made

9:31 the cometary delivery theory a bit

9:34 shaky.

9:35 Avery: Right. The fingerprints didn't match, so

9:38 scientists started looking more towards

9:40 asteroids as the primary water source.

9:43 Anna: Exactly. But this new measurement from

9:46 Pons Brooks changes the story. It's a

9:49 Halley type comet originating from the

9:51 icy Oort Cloud. And. And its water is

9:54 virtually indistinguishable from ours.

9:57 The fingerprint is a match.

10:00 Avery: So this single comet provides the strongest

10:03 evidence yet that its ancient relatives are

10:06 the reason we have oceans. Billions of years

10:09 ago, a relentless bombardment of comets like

10:12 Pons Brooks could have painted our dry,

10:14 rocky planet blue.

10:16 Anna: It makes the cometary origin of Earth's

10:19 water a leading theory. Once again, it

10:22 doesn't mean asteroids didn't contribute.

10:24 It was likely a combination of both.

10:27 But this is a huge piece of the puzzle.

10:30 Avery: It's incredible to think about. Every time

10:33 you have a glass of water, you might be

10:35 drinking the remnants of ancient comets that

10:37 travelled for billions of years across the

10:40 solar system. That's a, uh, truly cosmic

10:43 connection.

10:44 Anna: And what a profound thought to end on.

10:47 That's all the time we have for today on

10:49 Astronomy Daily. We've journeyed from a

10:52 new moon around Uranus to the very

10:55 origins of the water on our own

10:57 planet.

10:59 Avery: It's been another day of incredible

11:00 discoveries that remind us just how dynamic

11:03 and interconnected the universe is. Thank you

11:06 so much for joining us.

11:07 Anna: For more details on all today's stories and

11:10 links to the original research, be sure

11:13 to visit our

11:14 [email protected]

11:17 we'll be back tomorrow with more of the

11:20 latest news from across the cosmos.

11:23 Until then, I'm Anna.

11:25 Avery: And I'm Avery. Keep looking up