00:00:00 --> 00:00:03 Avery: Welcome back to Astronomy Daily, the
00:00:03 --> 00:00:05 podcast that brings the cosmos down to
00:00:05 --> 00:00:07 Earth. I'm your host, Avery.
00:00:08 --> 00:00:10 Anna: And I'm your other host, Anna. Uh, it's great
00:00:10 --> 00:00:13 to have you with us. We have an absolutely
00:00:13 --> 00:00:15 packed show for you today with news that
00:00:15 --> 00:00:16 spans our solar system.
00:00:17 --> 00:00:19 Avery: We are starting in the outer solar system
00:00:19 --> 00:00:22 with some incredible new findings from not
00:00:22 --> 00:00:25 one, but two of Saturn's moons.
00:00:25 --> 00:00:27 First up, Enceladus, which is looking
00:00:28 --> 00:00:30 more and more like a prime candidate for
00:00:30 --> 00:00:32 hosting extraterrestrial life.
00:00:33 --> 00:00:35 Anna: Then we'll stay in the same neighborhood to
00:00:35 --> 00:00:38 visit Titan, Saturn's largest moon, where
00:00:38 --> 00:00:40 its entire atmosphere appears to be doing
00:00:40 --> 00:00:43 something very strange, something scientists
00:00:43 --> 00:00:45 are comparing to a, uh, gyroscope.
00:00:45 --> 00:00:48 Avery: From there, we're taking a big leap inwards,
00:00:49 --> 00:00:51 all the way to our planetary neighbor,
00:00:51 --> 00:00:54 Venus. You might think you know Venus, but
00:00:54 --> 00:00:57 a fresh look at some very old data has
00:00:57 --> 00:00:59 turned our understanding of its clouds
00:00:59 --> 00:01:00 completely on its head.
00:01:01 --> 00:01:03 Anna: And to wrap things up, we'll bring it all
00:01:03 --> 00:01:05 back home. A new survey from Australia
00:01:05 --> 00:01:08 reveals a fascinating and perhaps slightly
00:01:08 --> 00:01:11 worrying gap between how much people support
00:01:11 --> 00:01:14 the space industry and how much they actually
00:01:14 --> 00:01:15 know about it.
00:01:15 --> 00:01:18 Avery: It's a journey from potential alien oceans
00:01:18 --> 00:01:21 to public opinion polls, so let's not
00:01:21 --> 00:01:22 waste any more time.
00:01:22 --> 00:01:24 Anna, uh, why don't you start us off with the
00:01:24 --> 00:01:26 exciting news from Enceladus.
00:01:26 --> 00:01:29 Anna: My pleasure, Avery. This story is a
00:01:29 --> 00:01:31 beautiful example of a mission that just
00:01:31 --> 00:01:34 keeps on giving. The Cassini spacecraft
00:01:34 --> 00:01:37 gave us two decades of incredible insights
00:01:37 --> 00:01:40 into Saturn. And even years after the mission
00:01:40 --> 00:01:42 ended, scientists are still mining its data
00:01:42 --> 00:01:43 for gold.
00:01:43 --> 00:01:46 Avery: And it seems they've struck a new vein.
00:01:46 --> 00:01:49 This is about those amazing water plumes,
00:01:49 --> 00:01:52 right? The ones Cassini actually flew
00:01:52 --> 00:01:52 through?
00:01:52 --> 00:01:55 Anna: That's the one. Almost 20 years ago,
00:01:55 --> 00:01:57 Cassini flew through plumes of water
00:01:58 --> 00:02:00 bursting from cracks in the icy surface of
00:02:00 --> 00:02:03 Enceladus. Now, a new analysis of
00:02:03 --> 00:02:06 that fly through data has confirmed what many
00:02:06 --> 00:02:09 had hoped, that complex chemical reactions
00:02:09 --> 00:02:11 are happening within the Moon's hidden
00:02:12 --> 00:02:13 subsurface ocean.
00:02:13 --> 00:02:16 Avery: That sounds huge. When we talk about
00:02:16 --> 00:02:18 searching for life, we're always looking for
00:02:18 --> 00:02:21 certain key ingredients. What does this new
00:02:21 --> 00:02:22 finding tell us?
00:02:22 --> 00:02:25 Anna: Well, it essentially affirms that Enceladus
00:02:25 --> 00:02:28 has all three of the major conditions
00:02:28 --> 00:02:31 necessary for a habitable environment, at
00:02:31 --> 00:02:33 least as we understand it. You need liquid
00:02:33 --> 00:02:36 water, which we know the Moon has, in its
00:02:36 --> 00:02:39 subsurface ocean. You need a source of
00:02:39 --> 00:02:42 energy, likely from hydrothermal vents on the
00:02:42 --> 00:02:44 ocean floor. And you need a specific
00:02:44 --> 00:02:47 set of chemical elements, the building blocks
00:02:47 --> 00:02:47 of life.
00:02:48 --> 00:02:51 Avery: And this new analysis adds more to that
00:02:51 --> 00:02:54 third category. The Chemical building blocks.
00:02:54 --> 00:02:56 Anna: Exactly. They found organic
00:02:56 --> 00:02:58 molecules, some new ones they hadn't detected
00:02:58 --> 00:03:01 before in the fresh ice grains that were
00:03:01 --> 00:03:04 ejected directly from the ocean. This
00:03:04 --> 00:03:07 included molecular fragments that potentially
00:03:07 --> 00:03:09 contain nitrogen and oxygen, which are
00:03:09 --> 00:03:12 crucial for life as we know it.
00:03:12 --> 00:03:15 Avery: So this is direct evidence of complex
00:03:15 --> 00:03:18 chemistry happening right now in that ocean.
00:03:18 --> 00:03:20 And Frank Postberg, one of the co authors,
00:03:20 --> 00:03:22 made a really important point about this,
00:03:22 --> 00:03:23 didn't he?
00:03:23 --> 00:03:26 Anna: He did. He emphasized that these molecules
00:03:26 --> 00:03:28 were found in freshly ejected material.
00:03:29 --> 00:03:32 This proves that the complex organics Cassini
00:03:32 --> 00:03:35 previously detected in Saturn's E ring
00:03:35 --> 00:03:37 aren't just the result of being zapped by
00:03:37 --> 00:03:40 radiation in space for a long time. They are
00:03:40 --> 00:03:42 being actively produced or are readily
00:03:42 --> 00:03:44 available right there in the ocean.
00:03:45 --> 00:03:47 Avery: So it's an active, chemically rich
00:03:47 --> 00:03:49 environment. And I believe another scientist
00:03:49 --> 00:03:52 on the paper, Nozair Kawasha, added that
00:03:52 --> 00:03:55 there are many possible chemical pathways
00:03:55 --> 00:03:57 that could lead from these simple organic
00:03:57 --> 00:03:59 molecules to more complex
00:03:59 --> 00:04:01 biologically relevant compounds.
00:04:01 --> 00:04:04 Anna: That's right. It significantly enhances the
00:04:04 --> 00:04:06 likelihood that the moon is habitable.
00:04:07 --> 00:04:09 We have to be clear, this is not evidence of
00:04:09 --> 00:04:12 life itself. But it is perhaps the
00:04:12 --> 00:04:14 strongest evidence yet that an environment
00:04:14 --> 00:04:16 that could support life exists, exists
00:04:17 --> 00:04:19 right now in our own solar system.
00:04:20 --> 00:04:22 Avery: Well, let's not leave the Saturn system just
00:04:22 --> 00:04:25 yet, because its biggest moon, Titan, is also
00:04:25 --> 00:04:27 making headlines with some very unusual
00:04:27 --> 00:04:27 behavior.
00:04:28 --> 00:04:31 Anna: That's right. If Enceladus is all about its
00:04:31 --> 00:04:34 hidden ocean, Titan is famous for its
00:04:34 --> 00:04:37 thick, hazy atmosphere. It's the only
00:04:37 --> 00:04:39 moon in our solar system with a substantial
00:04:39 --> 00:04:42 atmosphere, denser even than Earth.
00:04:43 --> 00:04:45 Avery: Um, and we've always known it's a weird place
00:04:45 --> 00:04:47 with its methane lakes and rivers. But now it
00:04:47 --> 00:04:49 seems the atmosphere itself is acting
00:04:49 --> 00:04:50 strangely.
00:04:50 --> 00:04:53 Anna: Researchers at the University of Bristol have
00:04:53 --> 00:04:56 uncovered that Titan's atmosphere doesn't
00:04:56 --> 00:04:59 rotate in step with its surface. The new
00:04:59 --> 00:05:01 discovery is that the entire atmospheric
00:05:01 --> 00:05:03 system seems to be tilted off axis,
00:05:04 --> 00:05:07 and it wobbles or oscillates almost
00:05:07 --> 00:05:09 like a spinning top or a gyroscope.
00:05:10 --> 00:05:13 Avery: The whole atmosphere is wobbling. How m is
00:05:13 --> 00:05:13 that possible?
00:05:13 --> 00:05:16 Anna: The prevailing theory is that some major
00:05:16 --> 00:05:18 event in Titan's past could have knocked the
00:05:18 --> 00:05:21 atmosphere off its original spin axis,
00:05:21 --> 00:05:24 causing it to wobble ever since. What's
00:05:24 --> 00:05:27 even stranger is that the size of this wobble
00:05:27 --> 00:05:30 actually changes with Titan's seasons.
00:05:30 --> 00:05:32 Avery: That has to be a critical piece of
00:05:32 --> 00:05:34 information for NASA's next big mission to
00:05:34 --> 00:05:35 the outer solar system.
00:05:36 --> 00:05:38 Anna: Absolutely. We're talking about the Dragonfly
00:05:38 --> 00:05:41 mission, the car sized drone like
00:05:41 --> 00:05:43 rotorcraft that's scheduled to arrive at
00:05:43 --> 00:05:46 titan in the2030s. Its whole
00:05:46 --> 00:05:49 mission is to fly through Titan's atmosphere.
00:05:49 --> 00:05:51 Avery: And if you're trying to land a multi billion
00:05:51 --> 00:05:53 dollar nuclear powered drone on a distant
00:05:53 --> 00:05:55 moon, you'd probably like to know if the
00:05:55 --> 00:05:58 entire atmosphere you're flying through is
00:05:58 --> 00:05:58 wobbling around.
00:05:59 --> 00:06:02 Anna: To put it mildly, yes. Understanding
00:06:02 --> 00:06:04 how the atmosphere behaves is absolutely
00:06:04 --> 00:06:06 crucial for calculating the landing
00:06:06 --> 00:06:09 trajectory. This discovery is a vital
00:06:09 --> 00:06:10 new piece of that puzzle.
00:06:11 --> 00:06:13 Avery: Okay, from the cold hazy reaches of the
00:06:13 --> 00:06:15 Saturn system, let's head sunward to a
00:06:15 --> 00:06:18 place that's anything but cold. Venus.
00:06:18 --> 00:06:20 And uh, for as long as I can remember, the
00:06:20 --> 00:06:23 defining feature of Venus has been its clouds
00:06:23 --> 00:06:24 of sulfuric acid.
00:06:25 --> 00:06:27 Anna: That has certainly been the dominant picture.
00:06:27 --> 00:06:30 But a new paper is challenging that in a
00:06:30 --> 00:06:32 fundamental way. A team of researchers
00:06:32 --> 00:06:34 decided to re, analyze, analyze data from
00:06:34 --> 00:06:37 NASA's Pioneer mission to Venus from the
00:06:37 --> 00:06:37 70s.
00:06:38 --> 00:06:41 Avery: I love these stories where old data reveals
00:06:41 --> 00:06:42 new secrets. What did they find?
00:06:43 --> 00:06:45 Anna: Pioneer analyzed aerosols in the clouds by
00:06:45 --> 00:06:47 seeing at what temperatures they burnt off.
00:06:48 --> 00:06:50 The researchers applied modern techniques to
00:06:50 --> 00:06:53 this old data and noticed massive spikes in
00:06:53 --> 00:06:53 water.
00:06:54 --> 00:06:56 Avery: So it's not a water cloud in the way we think
00:06:56 --> 00:06:59 of one on Earth, but water is a huge
00:06:59 --> 00:07:01 component of what it's making up the clouds.
00:07:01 --> 00:07:04 Anna: A, uh, huge component. It seems the water is
00:07:04 --> 00:07:07 locked up inside other minerals as
00:07:07 --> 00:07:09 hydrates. When they did the math, they found
00:07:09 --> 00:07:11 that this hydrated water made up the bulk of
00:07:11 --> 00:07:13 the aerosols, measured a, ah, staggering
00:07:13 --> 00:07:14 62%.
00:07:15 --> 00:07:17 Avery: This has enormous implications for one of the
00:07:17 --> 00:07:20 most exciting ideas in planetary science. The
00:07:20 --> 00:07:23 search for life in the clouds of Venus.
00:07:23 --> 00:07:26 Anna: It really does. One of the primary
00:07:26 --> 00:07:28 arguments against that possibility has always
00:07:28 --> 00:07:31 been the extreme lack of available water.
00:07:31 --> 00:07:34 But if water is actually far more abundant
00:07:34 --> 00:07:37 just chemically bound up, it completely
00:07:37 --> 00:07:40 changes the equation. It reopens the door to
00:07:40 --> 00:07:41 that possibility.
00:07:41 --> 00:07:44 And for our last story today, we're coming
00:07:44 --> 00:07:47 back to Earth. A new report has been released
00:07:47 --> 00:07:49 based on a survey of Australian opinions
00:07:49 --> 00:07:51 about space. And it reveals a really
00:07:51 --> 00:07:52 interesting picture.
00:07:53 --> 00:07:55 Avery: Let me guess, people love watching rocket
00:07:55 --> 00:07:56 launches but don't think about it much.
00:07:56 --> 00:07:59 Anna: Otherwise, that's a pretty good summary. The
00:07:59 --> 00:08:01 report shows a clear disconnect between the
00:08:01 --> 00:08:04 public's interest and their knowledge. People
00:08:04 --> 00:08:06 are three times more likely to want to
00:08:06 --> 00:08:09 increase spending on space, but awareness of
00:08:09 --> 00:08:11 what the sector actually does remains low.
00:08:12 --> 00:08:14 Avery: That's a key point. Things like using gps,
00:08:15 --> 00:08:17 checking the weather, or even making a credit
00:08:17 --> 00:08:19 card transaction often rely on data from
00:08:19 --> 00:08:21 satellites. It's this invisible
00:08:21 --> 00:08:23 infrastructure we take for granted.
00:08:24 --> 00:08:27 Anna: Precisely. The survey also found people
00:08:27 --> 00:08:29 want to see Australia pull its own weight and
00:08:29 --> 00:08:32 build its own space capabilities. And another
00:08:32 --> 00:08:35 point that came through very strongly was
00:08:35 --> 00:08:38 sustainability. Two thirds of respondents
00:08:38 --> 00:08:41 think it's important to invest in sustainable
00:08:41 --> 00:08:41 space practices.
00:08:42 --> 00:08:44 Avery: So the big takeaway is about communication.
00:08:45 --> 00:08:48 Anna: Exactly. The report concludes that there have
00:08:48 --> 00:08:51 to be real, tangible links made between this
00:08:51 --> 00:08:53 vital sector and the everyday lives of
00:08:53 --> 00:08:56 Australians, showing them how investments in
00:08:56 --> 00:08:59 space pay dividends right here on the ground.
00:08:59 --> 00:09:02 Avery: And that just about does it for us. Today we
00:09:02 --> 00:09:04 explored the life giving potential of, uh,
00:09:04 --> 00:09:07 Enceladus Ocean and the bizarre
00:09:07 --> 00:09:09 wobbling atmosphere of Titan.
00:09:09 --> 00:09:12 Anna: We rewrote the textbooks on the clouds of
00:09:12 --> 00:09:15 Venus and we took the pulse of public opinion
00:09:15 --> 00:09:17 on the importance of space right here on
00:09:17 --> 00:09:18 Earth.
00:09:18 --> 00:09:20 Avery: It's a constant reminder that there is always
00:09:20 --> 00:09:23 something new to discover. Thank you all so
00:09:23 --> 00:09:25 much for tuning in. I'm, uh, Avery. Thanks
00:09:25 --> 00:09:25 for.
00:09:25 --> 00:09:27 Anna: And I'm Anna. You've been listening to
00:09:27 --> 00:09:30 Astronomy Daily. For even more space
00:09:30 --> 00:09:33 and astronomy news, be sure to visit our
00:09:33 --> 00:09:36 website where we have a continuously updating
00:09:36 --> 00:09:38 newsfeed. You'll find us at
00:09:38 --> 00:09:41 astronomydaily IO. We'll
00:09:41 --> 00:09:43 be back tomorrow with all the latest news
00:09:43 --> 00:09:45 from our universe. Until then, keep looking
00:09:45 --> 00:09:46 up.