Enceladus' Ocean Secrets, Titan's Wobbling Atmosphere, and Venus' Water Revelation

0:00 Avery: Welcome back to Astronomy Daily, the

0:03 podcast that brings the cosmos down to

0:05 Earth. I'm your host, Avery.

0:08 Anna: And I'm your other host, Anna. Uh, it's great

0:10 to have you with us. We have an absolutely

0:13 packed show for you today with news that

0:15 spans our solar system.

0:17 Avery: We are starting in the outer solar system

0:19 with some incredible new findings from not

0:22 one, but two of Saturn's moons.

0:25 First up, Enceladus, which is looking

0:28 more and more like a prime candidate for

0:30 hosting extraterrestrial life.

0:33 Anna: Then we'll stay in the same neighborhood to

0:35 visit Titan, Saturn's largest moon, where

0:38 its entire atmosphere appears to be doing

0:40 something very strange, something scientists

0:43 are comparing to a, uh, gyroscope.

0:45 Avery: From there, we're taking a big leap inwards,

0:49 all the way to our planetary neighbor,

0:51 Venus. You might think you know Venus, but

0:54 a fresh look at some very old data has

0:57 turned our understanding of its clouds

0:59 completely on its head.

1:01 Anna: And to wrap things up, we'll bring it all

1:03 back home. A new survey from Australia

1:05 reveals a fascinating and perhaps slightly

1:08 worrying gap between how much people support

1:11 the space industry and how much they actually

1:14 know about it.

1:15 Avery: It's a journey from potential alien oceans

1:18 to public opinion polls, so let's not

1:21 waste any more time.

1:22 Anna, uh, why don't you start us off with the

1:24 exciting news from Enceladus.

1:26 Anna: My pleasure, Avery. This story is a

1:29 beautiful example of a mission that just

1:31 keeps on giving. The Cassini spacecraft

1:34 gave us two decades of incredible insights

1:37 into Saturn. And even years after the mission

1:40 ended, scientists are still mining its data

1:42 for gold.

1:43 Avery: And it seems they've struck a new vein.

1:46 This is about those amazing water plumes,

1:49 right? The ones Cassini actually flew

1:52 through?

1:52 Anna: That's the one. Almost 20 years ago,

1:55 Cassini flew through plumes of water

1:58 bursting from cracks in the icy surface of

2:00 Enceladus. Now, a new analysis of

2:03 that fly through data has confirmed what many

2:06 had hoped, that complex chemical reactions

2:09 are happening within the Moon's hidden

2:12 subsurface ocean.

2:13 Avery: That sounds huge. When we talk about

2:16 searching for life, we're always looking for

2:18 certain key ingredients. What does this new

2:21 finding tell us?

2:22 Anna: Well, it essentially affirms that Enceladus

2:25 has all three of the major conditions

2:28 necessary for a habitable environment, at

2:31 least as we understand it. You need liquid

2:33 water, which we know the Moon has, in its

2:36 subsurface ocean. You need a source of

2:39 energy, likely from hydrothermal vents on the

2:42 ocean floor. And you need a specific

2:44 set of chemical elements, the building blocks

2:47 of life.

2:48 Avery: And this new analysis adds more to that

2:51 third category. The Chemical building blocks.

2:54 Anna: Exactly. They found organic

2:56 molecules, some new ones they hadn't detected

2:58 before in the fresh ice grains that were

3:01 ejected directly from the ocean. This

3:04 included molecular fragments that potentially

3:07 contain nitrogen and oxygen, which are

3:09 crucial for life as we know it.

3:12 Avery: So this is direct evidence of complex

3:15 chemistry happening right now in that ocean.

3:18 And Frank Postberg, one of the co authors,

3:20 made a really important point about this,

3:22 didn't he?

3:23 Anna: He did. He emphasized that these molecules

3:26 were found in freshly ejected material.

3:29 This proves that the complex organics Cassini

3:32 previously detected in Saturn's E ring

3:35 aren't just the result of being zapped by

3:37 radiation in space for a long time. They are

3:40 being actively produced or are readily

3:42 available right there in the ocean.

3:45 Avery: So it's an active, chemically rich

3:47 environment. And I believe another scientist

3:49 on the paper, Nozair Kawasha, added that

3:52 there are many possible chemical pathways

3:55 that could lead from these simple organic

3:57 molecules to more complex

3:59 biologically relevant compounds.

4:01 Anna: That's right. It significantly enhances the

4:04 likelihood that the moon is habitable.

4:07 We have to be clear, this is not evidence of

4:09 life itself. But it is perhaps the

4:12 strongest evidence yet that an environment

4:14 that could support life exists, exists

4:17 right now in our own solar system.

4:20 Avery: Well, let's not leave the Saturn system just

4:22 yet, because its biggest moon, Titan, is also

4:25 making headlines with some very unusual

4:27 behavior.

4:28 Anna: That's right. If Enceladus is all about its

4:31 hidden ocean, Titan is famous for its

4:34 thick, hazy atmosphere. It's the only

4:37 moon in our solar system with a substantial

4:39 atmosphere, denser even than Earth.

4:43 Avery: Um, and we've always known it's a weird place

4:45 with its methane lakes and rivers. But now it

4:47 seems the atmosphere itself is acting

4:49 strangely.

4:50 Anna: Researchers at the University of Bristol have

4:53 uncovered that Titan's atmosphere doesn't

4:56 rotate in step with its surface. The new

4:59 discovery is that the entire atmospheric

5:01 system seems to be tilted off axis,

5:04 and it wobbles or oscillates almost

5:07 like a spinning top or a gyroscope.

5:10 Avery: The whole atmosphere is wobbling. How m is

5:13 that possible?

5:13 Anna: The prevailing theory is that some major

5:16 event in Titan's past could have knocked the

5:18 atmosphere off its original spin axis,

5:21 causing it to wobble ever since. What's

5:24 even stranger is that the size of this wobble

5:27 actually changes with Titan's seasons.

5:30 Avery: That has to be a critical piece of

5:32 information for NASA's next big mission to

5:34 the outer solar system.

5:36 Anna: Absolutely. We're talking about the Dragonfly

5:38 mission, the car sized drone like

5:41 rotorcraft that's scheduled to arrive at

5:43 titan in the2030s. Its whole

5:46 mission is to fly through Titan's atmosphere.

5:49 Avery: And if you're trying to land a multi billion

5:51 dollar nuclear powered drone on a distant

5:53 moon, you'd probably like to know if the

5:55 entire atmosphere you're flying through is

5:58 wobbling around.

5:59 Anna: To put it mildly, yes. Understanding

6:02 how the atmosphere behaves is absolutely

6:04 crucial for calculating the landing

6:06 trajectory. This discovery is a vital

6:09 new piece of that puzzle.

6:11 Avery: Okay, from the cold hazy reaches of the

6:13 Saturn system, let's head sunward to a

6:15 place that's anything but cold. Venus.

6:18 And uh, for as long as I can remember, the

6:20 defining feature of Venus has been its clouds

6:23 of sulfuric acid.

6:25 Anna: That has certainly been the dominant picture.

6:27 But a new paper is challenging that in a

6:30 fundamental way. A team of researchers

6:32 decided to re, analyze, analyze data from

6:34 NASA's Pioneer mission to Venus from the

6:37 70s.

6:38 Avery: I love these stories where old data reveals

6:41 new secrets. What did they find?

6:43 Anna: Pioneer analyzed aerosols in the clouds by

6:45 seeing at what temperatures they burnt off.

6:48 The researchers applied modern techniques to

6:50 this old data and noticed massive spikes in

6:53 water.

6:54 Avery: So it's not a water cloud in the way we think

6:56 of one on Earth, but water is a huge

6:59 component of what it's making up the clouds.

7:01 Anna: A, uh, huge component. It seems the water is

7:04 locked up inside other minerals as

7:07 hydrates. When they did the math, they found

7:09 that this hydrated water made up the bulk of

7:11 the aerosols, measured a, ah, staggering

7:13 62%.

7:15 Avery: This has enormous implications for one of the

7:17 most exciting ideas in planetary science. The

7:20 search for life in the clouds of Venus.

7:23 Anna: It really does. One of the primary

7:26 arguments against that possibility has always

7:28 been the extreme lack of available water.

7:31 But if water is actually far more abundant

7:34 just chemically bound up, it completely

7:37 changes the equation. It reopens the door to

7:40 that possibility.

7:41 And for our last story today, we're coming

7:44 back to Earth. A new report has been released

7:47 based on a survey of Australian opinions

7:49 about space. And it reveals a really

7:51 interesting picture.

7:53 Avery: Let me guess, people love watching rocket

7:55 launches but don't think about it much.

7:56 Anna: Otherwise, that's a pretty good summary. The

7:59 report shows a clear disconnect between the

8:01 public's interest and their knowledge. People

8:04 are three times more likely to want to

8:06 increase spending on space, but awareness of

8:09 what the sector actually does remains low.

8:12 Avery: That's a key point. Things like using gps,

8:15 checking the weather, or even making a credit

8:17 card transaction often rely on data from

8:19 satellites. It's this invisible

8:21 infrastructure we take for granted.

8:24 Anna: Precisely. The survey also found people

8:27 want to see Australia pull its own weight and

8:29 build its own space capabilities. And another

8:32 point that came through very strongly was

8:35 sustainability. Two thirds of respondents

8:38 think it's important to invest in sustainable

8:41 space practices.

8:42 Avery: So the big takeaway is about communication.

8:45 Anna: Exactly. The report concludes that there have

8:48 to be real, tangible links made between this

8:51 vital sector and the everyday lives of

8:53 Australians, showing them how investments in

8:56 space pay dividends right here on the ground.

8:59 Avery: And that just about does it for us. Today we

9:02 explored the life giving potential of, uh,

9:04 Enceladus Ocean and the bizarre

9:07 wobbling atmosphere of Titan.

9:09 Anna: We rewrote the textbooks on the clouds of

9:12 Venus and we took the pulse of public opinion

9:15 on the importance of space right here on

9:17 Earth.

9:18 Avery: It's a constant reminder that there is always

9:20 something new to discover. Thank you all so

9:23 much for tuning in. I'm, uh, Avery. Thanks

9:25 for.

9:25 Anna: And I'm Anna. You've been listening to

9:27 Astronomy Daily. For even more space

9:30 and astronomy news, be sure to visit our

9:33 website where we have a continuously updating

9:36 newsfeed. You'll find us at

9:38 astronomydaily IO. We'll

9:41 be back tomorrow with all the latest news

9:43 from our universe. Until then, keep looking

9:45 up.