- Seismic Secrets of the Moon: Explore new research revealing that our lunar neighbour is more seismically active than previously thought. This study highlights the potential risks posed by moonquakes to future lunar bases, emphasising the need for careful planning and site selection for long-term habitats on the Moon.
- - Dramatic Stellar Demise: Witness the extraordinary tale of a massive star's explosive end as it interacts with a black hole companion. This unprecedented event, captured in real time by an AI system, provides groundbreaking insights into the dynamics of stellar explosions and the role of binary interactions.
- - Unraveling the Mystery of Missing Sulphur: Delve into the cosmic enigma of sulphur's scarcity in the universe. Recent findings suggest that this essential element is not missing but rather locked away in solid forms within icy grains of interstellar dust, reshaping our understanding of its distribution and significance in planetary formation.
- - Rethinking Vesta: Discover how a reanalysis of data from NASA's Dawn spacecraft is challenging our perceptions of Vesta, one of the largest objects in the asteroid belt. This research proposes that Vesta may not be a failed protoplanet but rather a remnant of a larger differentiated planet destroyed in the early solar system, offering new insights into planetary evolution.
- For more cosmic updates, visit our website at astronomydaily.io. Join our community on social media by searching for #AstroDailyPod on Facebook, X, YouTube Music, TikTok, and our new Instagram account! Don’t forget to subscribe to the podcast on Apple Podcasts, Spotify, iHeartRadio, or wherever you get your podcasts.
- Thank you for tuning in. This is Anna and Avery signing off. Until next time, keep looking up and stay curious about the wonders of our universe.
Lunar Seismic Activity Study
[Smithsonian Institution](https://www.si.edu/)
Supernova SN2023ZKD Analysis
[Harvard-Smithsonian Center for Astrophysics](https://www.cfa.harvard.edu/)
Sulphur Research Findings
[Nature Communications](https://www.nature.com/ncomms/)
Vesta Reanalysis
[NASA TV Propulsion Laboratory](https://www.jpl.nasa.gov/)
Astronomy Daily
[Astronomy Daily](http://www.astronomydaily.io/)
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00:00:00 --> 00:00:02 Anna: Welcome back to Astronomy Daily, your go to
00:00:02 --> 00:00:05 podcast for all the latest happenings in our
00:00:05 --> 00:00:07 incredible universe. I'm Anna.
00:00:07 --> 00:00:10 Avery: And I'm Avery. We've got a big episode lined
00:00:10 --> 00:00:12 up for you today, packed with some truly
00:00:12 --> 00:00:14 fascinating cosmic updates.
00:00:14 --> 00:00:16 Anna: That's right, Avery. We'll be diving into new
00:00:16 --> 00:00:19 research about lunar seismic activity
00:00:19 --> 00:00:21 and what moonquakes could mean for future
00:00:21 --> 00:00:24 bases on our nearest celestial neighbour.
00:00:24 --> 00:00:27 Turns out the Moon is a lot shakier than you
00:00:27 --> 00:00:28 might think.
00:00:28 --> 00:00:31 Avery: And speaking of drama, we'll also explore the
00:00:31 --> 00:00:34 explosive end of a massive star that had a
00:00:34 --> 00:00:36 very close encounter with a black hole. It's
00:00:36 --> 00:00:39 a story straight out of a sci fi movie, but
00:00:39 --> 00:00:40 it's real.
00:00:40 --> 00:00:42 Anna: Plus, we're tackling some long standing
00:00:42 --> 00:00:45 cosmic mysteries, from the curious case of
00:00:45 --> 00:00:47 the universe's missing sulphur to
00:00:47 --> 00:00:50 groundbreaking new insights about Vesta, one
00:00:50 --> 00:00:53 of the largest objects in the asteroid belt.
00:00:53 --> 00:00:54 Which might be more than just an.
00:00:54 --> 00:00:57 Avery: Asteroid, but so buckle up because
00:00:57 --> 00:00:59 we're about to take a tour through the latest
00:00:59 --> 00:01:02 and greatest in space and astronomy news.
00:01:02 --> 00:01:05 Anna: Alright, let's kick things off with some big
00:01:05 --> 00:01:08 news about our own Moon. We often think
00:01:08 --> 00:01:10 of it as a quiet, unchanging place, but
00:01:10 --> 00:01:13 new research is challenging that idea,
00:01:13 --> 00:01:15 especially when we consider building long
00:01:15 --> 00:01:16 term bases there.
00:01:16 --> 00:01:19 Avery: That's right, Anna. It turns out our lunar
00:01:19 --> 00:01:22 neighbour is more seismically active than
00:01:22 --> 00:01:25 many might assume. A recent study focusing
00:01:25 --> 00:01:27 on the Lee Lincoln Fault in the Taurus
00:01:27 --> 00:01:30 Littrell Valley, where the Apollo 17
00:01:30 --> 00:01:32 astronauts landed in 1972,
00:01:32 --> 00:01:35 highlights that these moonquakes could pose
00:01:35 --> 00:01:37 significant risks to future permanent lunar
00:01:37 --> 00:01:38 structures.
00:01:38 --> 00:01:41 Anna: This research, led by Smithsonian Senior
00:01:41 --> 00:01:44 Scientist Emeritus Thomas R. Waters,
00:01:44 --> 00:01:47 emphasises that the global distribution of
00:01:47 --> 00:01:49 these young thrust faults and their potential
00:01:49 --> 00:01:52 to still be active needs to be seriously
00:01:52 --> 00:01:54 considered. We're talking about planning
00:01:54 --> 00:01:57 locations and assessing the stability of any
00:01:57 --> 00:01:59 permanent outposts on the Moon.
00:01:59 --> 00:02:02 Avery: And, um, the evidence isn't new. It's based
00:02:02 --> 00:02:04 on moonquakes in the region over the past 90
00:02:04 --> 00:02:07 million years. Much of this evidence comes
00:02:07 --> 00:02:09 from material gathered by the Apollo
00:02:09 --> 00:02:11 astronauts themselves. Things like chunks of
00:02:11 --> 00:02:14 rocks and landslides are silent. But clear
00:02:14 --> 00:02:17 proof of the power of even magnitude
00:02:17 --> 00:02:19 3.0 quakes to shift surface
00:02:19 --> 00:02:22 materials around it really points to the Moon
00:02:22 --> 00:02:24 still being geologically active.
00:02:25 --> 00:02:27 Anna: It makes you wonder, why does the Moon even
00:02:27 --> 00:02:29 have quakes here on Earth? We're very
00:02:29 --> 00:02:32 familiar with earthquakes, primarily caused
00:02:32 --> 00:02:34 by plate tectonics and volcanic activity.
00:02:34 --> 00:02:37 Think of the San Andreas Fault or the Ring of
00:02:37 --> 00:02:40 Fire. Magma movement also causes tremors,
00:02:40 --> 00:02:42 like the recent events in Hawaii and Iceland.
00:02:43 --> 00:02:45 Avery: But the Moon operates differently. Its quakes
00:02:45 --> 00:02:47 are most Likely caused by two main
00:02:48 --> 00:02:50 Earth's tidal pulling and the Moon's
00:02:50 --> 00:02:53 continuous cooling and shrinking. The deep
00:02:53 --> 00:02:55 moonquakes occurring hundreds of miles inside
00:02:56 --> 00:02:58 are due to Earth's gravity pulling on her
00:02:58 --> 00:02:59 satellite.
00:02:59 --> 00:03:01 Anna: And the weaker quakes closer to the surface
00:03:01 --> 00:03:03 are generally attributed to the Moon's
00:03:03 --> 00:03:06 gradual cooling and shrinking. Since its
00:03:06 --> 00:03:09 formation billions of years ago, the Moon has
00:03:09 --> 00:03:12 actually lost about 150ft of
00:03:12 --> 00:03:14 its diameter. There are also minor tremors
00:03:14 --> 00:03:17 from meteoroid impacts or surface rocks
00:03:17 --> 00:03:19 reacting to heating and cooling from the sun.
00:03:20 --> 00:03:22 So it's a world that's constantly shaking.
00:03:22 --> 00:03:25 Avery: When we talk about the risks to future bases,
00:03:25 --> 00:03:27 it becomes quite significant. Short term
00:03:27 --> 00:03:30 missions like the Apollo landings, where
00:03:30 --> 00:03:32 astronauts were on the Moon for less than two
00:03:32 --> 00:03:35 weeks, didn't face much danger. But for
00:03:35 --> 00:03:37 permanent bases, the chances of damage during
00:03:37 --> 00:03:40 a quake go up simply due to the extended
00:03:40 --> 00:03:41 exposure.
00:03:41 --> 00:03:44 Anna: Nicholas Schmer put it into perspective. He
00:03:44 --> 00:03:46 said if astronauts are there for a day,
00:03:46 --> 00:03:49 they'd just have very bad luck. If there was
00:03:49 --> 00:03:51 a damaging event, they. But if you have a
00:03:51 --> 00:03:53 habitat or crewed mission up on the Moon for
00:03:53 --> 00:03:55 a whole decade, that's
00:03:55 --> 00:03:58 3 days times 1
00:03:58 --> 00:04:01 in 20 million. Or the risk of a hazardous
00:04:01 --> 00:04:03 moonquake becoming about 1 in 5.
00:04:04 --> 00:04:06 Avery: He likened it to, uh, going from the
00:04:06 --> 00:04:09 extremely low odds of winning a lottery
00:04:09 --> 00:04:12 to the much higher odds of being dealt a four
00:04:12 --> 00:04:14 of a kind poker hand. It really illustrates
00:04:14 --> 00:04:17 how much the probability increases over time.
00:04:18 --> 00:04:21 Anna: And it's not just habitats. Countries like
00:04:21 --> 00:04:24 Russia, China and the US are planning to put
00:04:24 --> 00:04:26 nuclear power plants on the Moon. These
00:04:26 --> 00:04:29 facilities would supply massive amounts of
00:04:29 --> 00:04:31 power, but they'd also be susceptible to
00:04:31 --> 00:04:34 quake damage. This means any construction
00:04:34 --> 00:04:36 will need tough safety margins and shouldn't
00:04:36 --> 00:04:38 be located near active fault lines.
00:04:39 --> 00:04:42 Avery: Which is a tall order considering how many
00:04:42 --> 00:04:44 fault lines thread through the Moon. That's
00:04:44 --> 00:04:47 why this study of lunar paleoseismology
00:04:47 --> 00:04:50 looking at evidence of past quakes is so
00:04:50 --> 00:04:53 crucial. It will help us chart the safest
00:04:53 --> 00:04:55 places to build these long term habitats and
00:04:55 --> 00:04:57 power plants. It's all about understanding
00:04:57 --> 00:04:59 our cosmic neighbourhood.
00:04:59 --> 00:05:01 Before we make ourselves at home from
00:05:01 --> 00:05:04 lunar shaking, let's zoom out to something
00:05:04 --> 00:05:06 truly dramatic happening in the cosmos.
00:05:06 --> 00:05:09 Scientists have captured the explosive end of
00:05:09 --> 00:05:12 a massive star in a scenario unlike
00:05:12 --> 00:05:13 anything they've seen before.
00:05:14 --> 00:05:17 Anna: That's right, Avery. This event, more than
00:05:17 --> 00:05:20 700 million light years away, began as
00:05:20 --> 00:05:22 a faint flicker. Within days, the light
00:05:22 --> 00:05:25 flared, faded, and then, surprisingly,
00:05:25 --> 00:05:28 flared again. It was completely
00:05:28 --> 00:05:31 unlike the standard playbook for dying stars.
00:05:31 --> 00:05:34 Avery: What makes this even more incredible is that
00:05:34 --> 00:05:36 an artificial intelligence System flagged the
00:05:36 --> 00:05:39 event in real time. This allowed scientists
00:05:39 --> 00:05:42 to capture every phase of what may be the
00:05:42 --> 00:05:44 first recorded case of a massive star
00:05:44 --> 00:05:47 exploding as it tried to devour a black
00:05:47 --> 00:05:50 hole companion. Talk about cosmic drama.
00:05:50 --> 00:05:51 This supernova, named
00:05:51 --> 00:05:54 SN2023ZKD, was
00:05:54 --> 00:05:57 first spotted in July 2023 by the Zwicky
00:05:57 --> 00:06:00 Transient Facility and then analysed by a
00:06:00 --> 00:06:02 team from the Centre for Astrophysics at
00:06:02 --> 00:06:05 Harvard and Smithsonian mit. Their
00:06:05 --> 00:06:07 findings, published in the Astrophysical
00:06:07 --> 00:06:10 Journal, provide the clearest evidence yet
00:06:10 --> 00:06:12 that such extreme binary interactions can
00:06:12 --> 00:06:15 actually trigger a stellar detonation. It
00:06:15 --> 00:06:18 was part of the Young Supernova Experiment, a
00:06:18 --> 00:06:20 project designed to catch these exploding
00:06:20 --> 00:06:23 stars in their earliest stages. The AI system
00:06:23 --> 00:06:25 gave astronomers a crucial head start,
00:06:25 --> 00:06:28 allowing them to follow the explosion in near
00:06:28 --> 00:06:30 real time from both ground and space
00:06:30 --> 00:06:31 observatories.
00:06:32 --> 00:06:35 Anna: Alexander Agliano, the lead author of
00:06:35 --> 00:06:37 the study, stated that their analysis shows
00:06:37 --> 00:06:39 the blast was sparked by a catastrophic
00:06:39 --> 00:06:41 encounter with a black hole companion,
00:06:42 --> 00:06:44 providing the strongest evidence to date that
00:06:44 --> 00:06:47 such close interactions can indeed
00:06:47 --> 00:06:48 detonate a star.
00:06:49 --> 00:06:51 Avery: The leading explanation is that this massive
00:06:51 --> 00:06:54 star and black hole were locked in a decaying
00:06:54 --> 00:06:56 orbit. As they drew closer, the black hole's
00:06:56 --> 00:06:59 immense gravity pulled gas from the star into
00:06:59 --> 00:07:02 a surrounding disc. This intense stress is
00:07:02 --> 00:07:04 believed to have triggered the explosion
00:07:04 --> 00:07:06 before the star could fully engulf the black
00:07:06 --> 00:07:07 hole.
00:07:08 --> 00:07:10 Anna: Another possibility is that the black hole
00:07:10 --> 00:07:12 completely shredded the star, with the
00:07:12 --> 00:07:15 debris's collisions then powering the
00:07:15 --> 00:07:17 supernova's light. In either scenario,
00:07:17 --> 00:07:20 the aftermath left behind a heavier black
00:07:20 --> 00:07:21 hole.
00:07:21 --> 00:07:24 Avery: What really stood out to astronomers were the
00:07:24 --> 00:07:26 unusual light patterns from Earth.
00:07:26 --> 00:07:29 SN2023ZKD initially
00:07:29 --> 00:07:31 looked like a normal supernova. A single
00:07:31 --> 00:07:34 burst of light followed by a gradual fade.
00:07:34 --> 00:07:36 But then, months later, it did something
00:07:36 --> 00:07:39 truly extraordinary. It brightened again.
00:07:40 --> 00:07:43 Anna: Archival records showed that the system had
00:07:43 --> 00:07:45 actually been slowly brightening for more
00:07:45 --> 00:07:48 than four years before the explosion,
00:07:48 --> 00:07:51 a rare and telling sign of pre death
00:07:51 --> 00:07:54 instability. The analysis revealed that the
00:07:54 --> 00:07:57 supernova's light was shaped by layers of gas
00:07:57 --> 00:07:59 shed by the star in its final years.
00:07:59 --> 00:08:01 Avery: The first brightening came from the blast
00:08:01 --> 00:08:03 wave colliding with diffused gas, while while
00:08:03 --> 00:08:05 that second peak was fueled by a slower
00:08:05 --> 00:08:08 collision with a dense disc shaped cloud.
00:08:08 --> 00:08:10 The structure and timing of these events
00:08:10 --> 00:08:12 strongly point to extreme gravitational
00:08:12 --> 00:08:15 forces from a nearby compact object.
00:08:15 --> 00:08:18 Anna: It's clear that AI played a crucial role
00:08:18 --> 00:08:20 here. As Gagliano mentioned, their machine
00:08:20 --> 00:08:22 Learning system flagged
00:08:22 --> 00:08:25 SN2023SKD months
00:08:25 --> 00:08:28 before its most unusual behaviour, which gave
00:08:28 --> 00:08:30 them ample time to secure the critical
00:08:30 --> 00:08:33 observations needed to unravel this
00:08:33 --> 00:08:36 extraordinary explosion V. Ashley Villar,
00:08:36 --> 00:08:36 a.
00:08:36 --> 00:08:38 Avery: AH co author and assistant professor of
00:08:38 --> 00:08:41 astronomy at cfa, added that this event shows
00:08:41 --> 00:08:43 some of the clearest signs they've seen of a
00:08:43 --> 00:08:45 massive star interacting with the companion
00:08:45 --> 00:08:47 in the years before an explosion. They
00:08:47 --> 00:08:49 believe this might be part of a whole class
00:08:49 --> 00:08:52 of hidden explosions that AI will help them
00:08:52 --> 00:08:53 discover in the future.
00:08:53 --> 00:08:56 Anna: With new observatories like the veracy Rubin
00:08:56 --> 00:08:59 Observatory soon scanning the entire sky
00:08:59 --> 00:09:01 every few nights and projects like the Young
00:09:01 --> 00:09:04 Supernova Experiment continuing to identify
00:09:04 --> 00:09:07 new events quickly, astronomers expect expect
00:09:07 --> 00:09:09 to catch more of these rare and complex
00:09:09 --> 00:09:12 explosions in action. It's truly
00:09:12 --> 00:09:15 a new era for observing the most extreme
00:09:15 --> 00:09:18 cosmic events. That's an incredible story
00:09:18 --> 00:09:20 of cosmic violence and detection.
00:09:20 --> 00:09:23 Now let's shift gears a bit and delve into a
00:09:23 --> 00:09:26 long standing cosmic mystery. The case of
00:09:26 --> 00:09:28 the universe's missing sulphur.
00:09:28 --> 00:09:30 Avery: It sounds like something out of a detective
00:09:30 --> 00:09:32 novel. For years, scientists have been
00:09:32 --> 00:09:34 puzzled because there simply isn't as much
00:09:34 --> 00:09:37 sulphur floating around in deep space as they
00:09:37 --> 00:09:39 expected. This is quite an enigma,
00:09:39 --> 00:09:41 considering Sulphur is the 10th most abundant
00:09:41 --> 00:09:44 element in the universe and crucial for both
00:09:44 --> 00:09:45 planets and life.
00:09:45 --> 00:09:48 Anna: Exactly. But a, uh, new international study
00:09:48 --> 00:09:51 might have finally found its hiding place.
00:09:51 --> 00:09:53 Researchers from the University of
00:09:53 --> 00:09:55 Mississippi, the University of Hawaii at
00:09:55 --> 00:09:58 Manoa and Georgia State University teamed
00:09:58 --> 00:10:00 up to search for answers, publishing their
00:10:00 --> 00:10:02 findings in Nature Communication.
00:10:03 --> 00:10:06 Avery: So where has all the sulphur been? The team's
00:10:06 --> 00:10:07 results suggest that it's not actually
00:10:07 --> 00:10:10 missing at all. Instead, it's locked away in
00:10:10 --> 00:10:13 solid forms, bound within icy grains of
00:10:13 --> 00:10:14 interstellar dust.
00:10:14 --> 00:10:17 Anna: In these frigid environments, sulphur atoms
00:10:17 --> 00:10:19 can arrange themselves in two main
00:10:19 --> 00:10:22 neat eight atom rings called
00:10:22 --> 00:10:24 octasulfur crowns and chains of
00:10:24 --> 00:10:27 sulphur atoms connected by hydrogen, known
00:10:27 --> 00:10:30 as polysulfons. These structures
00:10:30 --> 00:10:33 literally stick to icy dust grains,
00:10:33 --> 00:10:35 essentially freezing the sulphur out of view.
00:10:35 --> 00:10:37 Avery: It's fascinating how a common element on
00:10:37 --> 00:10:40 Earth found in volcanoes and power plants
00:10:40 --> 00:10:43 can be so elusive in space. Ralph
00:10:43 --> 00:10:45 Kaiser, one of the lead researchers,
00:10:45 --> 00:10:47 explained that the observed amount of sulphur
00:10:47 --> 00:10:50 in dense molecular clouds is three orders of
00:10:50 --> 00:10:52 magnitude less than predicted gas phase
00:10:52 --> 00:10:55 abundances. That's a huge difference.
00:10:55 --> 00:10:58 Anna: Astronomers typically identify elements in
00:10:58 --> 00:11:00 space by detecting the unique patterns of
00:11:00 --> 00:11:03 light they emit or absorb. While tools
00:11:03 --> 00:11:06 like James Webb Space Telescope can easily
00:11:06 --> 00:11:09 pick out oxygen, carbon and nitrogen,
00:11:09 --> 00:11:11 sulphur just doesn't follow the rules in the
00:11:11 --> 00:11:14 same way. As researcher uh, Ryan Fortenberry
00:11:14 --> 00:11:16 noted, when you do that for sulphur, it's out
00:11:16 --> 00:11:17 of whack.
00:11:17 --> 00:11:20 Avery: Another challenge is sulfur's shape. Shifting
00:11:20 --> 00:11:23 nature. Fortenberry likened it to a virus
00:11:23 --> 00:11:25 always changing shape as it moves, making it
00:11:25 --> 00:11:28 incredibly difficult to track. But this new
00:11:28 --> 00:11:30 research points to stable molecular forms
00:11:30 --> 00:11:32 that astronomers can now specifically hunt
00:11:32 --> 00:11:35 for using advanced radio telescopes.
00:11:35 --> 00:11:38 Anna: By recreating the conditions of deep space in
00:11:38 --> 00:11:40 laboratory experiments, the researchers
00:11:40 --> 00:11:43 confirmed that these solid sulphur compounds
00:11:43 --> 00:11:46 could indeed form on icy surfaces.
00:11:46 --> 00:11:49 And here's the Once these icy grains are
00:11:49 --> 00:11:52 heated in young star systems, the sulphur can
00:11:52 --> 00:11:54 sublime, meaning it transforms directly from
00:11:54 --> 00:11:57 a solid to a gas, making it finally
00:11:57 --> 00:11:58 detectable from Earth.
00:11:59 --> 00:12:00 Avery: This work could finally help astronomers
00:12:00 --> 00:12:03 piece together sulfur's role in both the
00:12:03 --> 00:12:05 formation of planets and the very chemistry
00:12:05 --> 00:12:08 that supports life. If they can pinpoint
00:12:08 --> 00:12:10 exactly where sulphur is stored, it could
00:12:10 --> 00:12:12 deepen our understanding of how essential
00:12:12 --> 00:12:14 life building elements are distributed across
00:12:14 --> 00:12:17 the cosmos. And, um, even improve models of
00:12:17 --> 00:12:19 planetary atmospheres, especially for
00:12:19 --> 00:12:20 exoplanets.
00:12:20 --> 00:12:22 Anna: It's a perfect example of astrochemistry
00:12:22 --> 00:12:25 forcing hard questions and leading to
00:12:25 --> 00:12:28 creative solutions. As Fortenberry put it,
00:12:28 --> 00:12:31 this kind of foundational research has the
00:12:31 --> 00:12:34 potential for significant unintended positive
00:12:34 --> 00:12:36 consequences for our broader understanding of
00:12:36 --> 00:12:37 the universe.
00:12:38 --> 00:12:39 Avery: That's a great point, Anna.
00:12:39 --> 00:12:41 Speaking of profound insights into how
00:12:41 --> 00:12:44 celestial bodies form, our next story
00:12:44 --> 00:12:46 completely redefines what we thought we knew
00:12:46 --> 00:12:49 about Vesta, one of the largest objects in
00:12:49 --> 00:12:51 the asteroid belt. For years, astronomers
00:12:51 --> 00:12:54 viewed Vesta as almost a miniature version of
00:12:54 --> 00:12:56 Earth, something between a rock in space and
00:12:56 --> 00:12:59 a full fledged planet due to its rocky
00:12:59 --> 00:13:02 surface, distinct layers, and volcanic
00:13:02 --> 00:13:02 history.
00:13:02 --> 00:13:05 Anna: But new research is truly shaking up that
00:13:05 --> 00:13:08 view. Data collected from NASA's dawn
00:13:08 --> 00:13:11 spacecraft, reanalyzed years later,
00:13:11 --> 00:13:13 is rewriting our understanding of how early
00:13:13 --> 00:13:16 planets may have formed and what might have
00:13:16 --> 00:13:17 gone wrong in Vesta's case.
00:13:18 --> 00:13:20 Avery: M the Dante spacecraft orbited Vesta from
00:13:20 --> 00:13:23 2011 to 2012, meticulously
00:13:23 --> 00:13:25 mapping its surface and measuring its
00:13:25 --> 00:13:27 gravity. Initially, this data suggested
00:13:27 --> 00:13:30 Vesta had undergone planetary
00:13:30 --> 00:13:32 differentiation, the process where dense
00:13:32 --> 00:13:35 materials sink to form a core and
00:13:35 --> 00:13:37 lighter materials create a mantle and crust.
00:13:37 --> 00:13:40 The Just like Earth or Mars, Vesta's
00:13:40 --> 00:13:43 volcanic surface seemed to confirm this.
00:13:43 --> 00:13:46 Anna: However, a decade after Dawn's mission ended
00:13:46 --> 00:13:49 in 2018, researchers at NASA's Jet
00:13:49 --> 00:13:52 Propulsion Lab, or JPL, decided to take
00:13:52 --> 00:13:54 a fresh look at the data, using better
00:13:54 --> 00:13:57 calibration and updated processing tools.
00:13:58 --> 00:14:00 And what they found completely challenged
00:14:00 --> 00:14:03 that long held Vesta may not have
00:14:03 --> 00:14:04 a core at all.
00:14:05 --> 00:14:07 Avery: That's a huge revelation. Ryan Park, a
00:14:07 --> 00:14:09 senior research scientist and principal
00:14:09 --> 00:14:12 engineer at jpl, expressed excitement,
00:14:12 --> 00:14:14 saying they were thrilled to confirm the
00:14:14 --> 00:14:17 data's strength in revealing Vesta's deep
00:14:17 --> 00:14:20 interior. By reanalyzing the dawn data,
00:14:20 --> 00:14:22 the team made a more precise estimate of, uh,
00:14:22 --> 00:14:25 Vesta's moment of inertia.
00:14:25 --> 00:14:28 Anna: For those wondering, the moment of inertia is
00:14:28 --> 00:14:31 a physics concept that reveals how mass is
00:14:31 --> 00:14:33 distributed within a rotating body.
00:14:34 --> 00:14:36 Assistant Professor Seth Jacobson of Michigan
00:14:36 --> 00:14:39 State University explained it with a simple
00:14:40 --> 00:14:42 Think of a figure skater. When they pull
00:14:42 --> 00:14:45 their arms in, they spin faster. When they
00:14:45 --> 00:14:47 stretch their arms out, they slow down.
00:14:48 --> 00:14:50 Celestial bodies with dense cores behave like
00:14:50 --> 00:14:53 skaters with their arms in rotating
00:14:53 --> 00:14:54 differently.
00:14:54 --> 00:14:56 Avery: And Vesta's behaviour simply didn't match
00:14:56 --> 00:14:59 what scientists expected from a core bearing
00:14:59 --> 00:15:02 body. Its moment of inertia and calculated
00:15:02 --> 00:15:04 at only 6.6% lower than a
00:15:04 --> 00:15:07 perfectly uniform structure suggests its
00:15:07 --> 00:15:10 internal structure is. Surprisingly, even
00:15:10 --> 00:15:13 this value points to only a mild difference
00:15:13 --> 00:15:16 in density beneath its crust, not the
00:15:16 --> 00:15:18 deep layering we see in fully differentiated
00:15:18 --> 00:15:19 planets.
00:15:20 --> 00:15:22 Anna: This new perspective has forced scientists to
00:15:22 --> 00:15:24 rethink everything they thought they knew
00:15:24 --> 00:15:26 about Vesta's formation. They're now
00:15:26 --> 00:15:29 exploring two main ideas. The first
00:15:29 --> 00:15:32 is that Vesta began to differentiate. Its
00:15:32 --> 00:15:34 insides started to melt and separate into
00:15:34 --> 00:15:37 layers. But something interrupted the
00:15:37 --> 00:15:39 process. This could have been a late start in
00:15:39 --> 00:15:42 forming or limited exposure to heat producing
00:15:42 --> 00:15:45 elements like radioactive aluminium.
00:15:45 --> 00:15:47 Avery: 26 the second theory is even more
00:15:47 --> 00:15:50 dramatic. It suggests Vesta might be the
00:15:50 --> 00:15:52 shattered remnants of a much larger
00:15:52 --> 00:15:55 differentiated planet. That body could have
00:15:55 --> 00:15:57 been destroyed in a massive collision during
00:15:57 --> 00:16:00 the solar system's early years. And Vesta
00:16:00 --> 00:16:02 would then be just one of the reassembled
00:16:02 --> 00:16:05 pieces, essentially chunky space debris of,
00:16:05 --> 00:16:08 uh, a growing world that never quite made
00:16:08 --> 00:16:10 it. Seth Jacobson, who initially
00:16:10 --> 00:16:13 considered this idea a stretch years ago,
00:16:13 --> 00:16:14 now takes it seriously.
00:16:15 --> 00:16:18 Anna: The mystery deepens when you consider Vesta's
00:16:18 --> 00:16:20 meteorites. Researchers have collected
00:16:20 --> 00:16:23 thousands of space rocks on Earth believed to
00:16:23 --> 00:16:25 have come from Vesta. And these meteorites
00:16:25 --> 00:16:27 look like they formed in a molten environment
00:16:28 --> 00:16:31 showing signs of volcanic activity. However,
00:16:31 --> 00:16:34 they don't obviously suggest incomplete
00:16:34 --> 00:16:37 differentiation, which creates a problem for
00:16:37 --> 00:16:39 the first hypothesis of partial melting.
00:16:39 --> 00:16:42 Avery: That's quite the conundrum. The second idea,
00:16:42 --> 00:16:45 where Vesta is a remnant of a larger
00:16:45 --> 00:16:48 destroyed planet, might better explain the
00:16:48 --> 00:16:51 rocks by. But it also raises new questions
00:16:51 --> 00:16:53 about how such a colossal collision would
00:16:53 --> 00:16:56 occur. Jacobson's lab is actively
00:16:56 --> 00:16:58 modelling what those collisions m might have
00:16:58 --> 00:17:00 looked like and how debris like Vesta might
00:17:00 --> 00:17:01 have formed.
00:17:01 --> 00:17:04 Anna: Ultimately, Vesta's internal structure holds
00:17:04 --> 00:17:07 the key to understanding how planets grow
00:17:07 --> 00:17:10 or fail to. For a long time,
00:17:10 --> 00:17:12 Vesta seemed like a textbook
00:17:12 --> 00:17:15 protoplanet, an object that started forming
00:17:15 --> 00:17:17 but didn't quite make it. Now
00:17:18 --> 00:17:20 that picture has become much blurrier.
00:17:21 --> 00:17:24 Avery: Instead of being a failed planet, Vesta might
00:17:24 --> 00:17:26 be something even more intriguing. A, uh,
00:17:26 --> 00:17:29 survivor of cosmic violence. If it
00:17:29 --> 00:17:32 truly is a chunk of a planet destroyed in the
00:17:32 --> 00:17:34 early solar system, it could provide
00:17:34 --> 00:17:37 scientists with invaluable insights into the
00:17:37 --> 00:17:40 collisions and processes that shaped the
00:17:40 --> 00:17:41 worlds we see today.
00:17:42 --> 00:17:45 Anna: As Jacobsen puts it, no longer is the Vesta,
00:17:45 --> 00:17:48 um, meteorite collection a sample of a body
00:17:48 --> 00:17:50 in space that failed to make it as a planet.
00:17:51 --> 00:17:54 These could be pieces of an ancient planet
00:17:54 --> 00:17:57 before it grew to full completion. We just
00:17:57 --> 00:17:58 don't know which planet that is yet.
00:17:59 --> 00:18:02 Avery: This discovery is a powerful reminder that in
00:18:02 --> 00:18:05 science, answers often lead to more
00:18:05 --> 00:18:08 questions. This reanalysis of old
00:18:08 --> 00:18:10 data isn't just changing our understanding of
00:18:10 --> 00:18:13 one asteroid. It could reshape how
00:18:13 --> 00:18:15 researchers think about early planetary
00:18:15 --> 00:18:18 formation across the entire solar system.
00:18:18 --> 00:18:21 Anna: And that's it for this episode. What a
00:18:21 --> 00:18:24 journey we've had today. From the surprising
00:18:24 --> 00:18:27 seismic activity of our moon and the critical
00:18:27 --> 00:18:30 implications for future lunar bases, to the
00:18:30 --> 00:18:32 mind boggling explosion of a star trying to
00:18:32 --> 00:18:35 swallow a block whole, the universe
00:18:35 --> 00:18:37 certainly keeps us on our toes.
00:18:38 --> 00:18:40 Avery: Absolutely, Anna. Uh, and let's not forget
00:18:40 --> 00:18:43 the cosmic mystery of the missing sulphur,
00:18:43 --> 00:18:45 now believed to be hidden in icy dust, uh,
00:18:45 --> 00:18:48 grains. And the groundbreaking reanalysis of
00:18:48 --> 00:18:51 Vesta, which challenges its long held
00:18:51 --> 00:18:53 status as a protoplanet, suggesting it might
00:18:53 --> 00:18:56 be a fragment of a destroyed world.
00:18:56 --> 00:18:59 Anna: It's been a day packed with fascinating
00:18:59 --> 00:19:01 discoveries that push the boundaries of our
00:19:01 --> 00:19:02 understanding.
00:19:02 --> 00:19:05 Avery: Indeed. Thank you for joining us on Astronomy
00:19:05 --> 00:19:08 Daily. We hope you enjoyed diving into the
00:19:08 --> 00:19:09 latest space news with us.
00:19:10 --> 00:19:12 Anna: We look forward to having you back next time
00:19:12 --> 00:19:14 for more amazing insights from across the
00:19:14 --> 00:19:17 cosmos. Until then, keep looking up.