00:00:00 --> 00:00:03 Welcome to Astronomy Daily, the podcast
00:00:03 --> 00:00:05 that brings you the biggest news from
00:00:05 --> 00:00:07 across the cosmos. I'm Avery.
00:00:07 --> 00:00:10 >> And I'm Anna. We have a fascinating show
00:00:10 --> 00:00:13 for you today. We'll be looking at our
00:00:13 --> 00:00:15 mysterious interstellar object friend
00:00:15 --> 00:00:18 that's prompting secret space drills.
00:00:18 --> 00:00:20 >> We're also celebrating the 30th
00:00:20 --> 00:00:22 anniversary of a legendary solar
00:00:22 --> 00:00:26 observatory and diving into how AI is
00:00:26 --> 00:00:29 revolutionizing spacecraft propulsion.
00:00:29 --> 00:00:32 Plus, a hypersonic space gun, a preview
00:00:32 --> 00:00:35 of one of the best meteor showers of the
00:00:35 --> 00:00:37 year, and we'll solve a decad's old
00:00:37 --> 00:00:40 mystery from Voyager 2's journey to
00:00:40 --> 00:00:41 Uranus.
00:00:41 --> 00:00:43 >> Anna, let's start with something that
00:00:43 --> 00:00:46 has the astronomical community buzzing.
00:00:46 --> 00:00:49 The interstellar object known as threey
00:00:49 --> 00:00:51 Atlas is back in the spotlight.
00:00:51 --> 00:00:54 >> It certainly is, Avery. This object
00:00:54 --> 00:00:57 which came from outside our solar system
00:00:57 --> 00:00:59 is exhibiting some very strange
00:00:59 --> 00:01:01 behavior. Scientists have noted what
00:01:02 --> 00:01:04 they call non-gravitational
00:01:04 --> 00:01:05 acceleration.
00:01:05 --> 00:01:07 >> Meaning it's changing speed in a way
00:01:08 --> 00:01:10 that can't be explained by the pole of
00:01:10 --> 00:01:11 the sun or planets.
00:01:12 --> 00:01:14 >> Exactly. And it's not outgassing like a
00:01:14 --> 00:01:17 typical comet. Instead, it seems to have
00:01:17 --> 00:01:21 these strange focused jets pointing away
00:01:21 --> 00:01:25 from the sun, forming an anti-tail. It's
00:01:25 --> 00:01:26 a real puzzle.
00:01:26 --> 00:01:28 >> And this puzzle is getting some serious
00:01:28 --> 00:01:31 attention. There have been a series of
00:01:31 --> 00:01:34 coordinated but very quiet space defense
00:01:34 --> 00:01:38 drills involving the ESA, Japan, the US,
00:01:38 --> 00:01:41 Australia, and several other nations.
00:01:41 --> 00:01:43 >> That's right. The official line is that
00:01:43 --> 00:01:45 they are standard preparedness
00:01:45 --> 00:01:48 exercises, but the timing is
00:01:48 --> 00:01:50 conspicuous, especially with ThreeI
00:01:50 --> 00:01:53 Atlas's closest approach to Earth
00:01:53 --> 00:01:55 happening on December 19th.
00:01:55 --> 00:01:58 >> It adds a layer of intrigue, especially
00:01:58 --> 00:02:00 when you consider some of the more out
00:02:00 --> 00:02:01 there theories.
00:02:02 --> 00:02:04 >> You're thinking of Aviab's hypothesis.
00:02:04 --> 00:02:07 >> I am. He suggested that threeey atlas
00:02:08 --> 00:02:10 might not be a single object but a
00:02:10 --> 00:02:13 primary craft accompanied by a swarm of
00:02:13 --> 00:02:15 smaller probes. Now that is pure
00:02:16 --> 00:02:17 speculation of course.
00:02:17 --> 00:02:20 >> Pure speculation but it highlights just
00:02:20 --> 00:02:22 how little we understand about this
00:02:22 --> 00:02:25 visitor. Whatever its nature, its
00:02:25 --> 00:02:27 strange dynamics and the heightened
00:02:27 --> 00:02:30 military interest mean that countless
00:02:30 --> 00:02:33 telescopes will be tracking it very,
00:02:33 --> 00:02:35 very closely in the coming weeks.
00:02:35 --> 00:02:38 >> Well, from a mysterious newcomer to a
00:02:38 --> 00:02:41 celebrated veteran, our next story is
00:02:41 --> 00:02:44 about a truly remarkable achievement.
00:02:44 --> 00:02:47 Happy 30th anniversary to the Solar and
00:02:47 --> 00:02:51 Heliospheric Observatory, or SOHO. An
00:02:51 --> 00:02:54 incredible milestone. When SOHO
00:02:54 --> 00:02:56 launched, its primary mission was
00:02:56 --> 00:02:58 scheduled to last just two years. 30
00:02:58 --> 00:03:01 years later, it's still providing
00:03:01 --> 00:03:03 invaluable data about our star.
00:03:03 --> 00:03:05 >> It really is the definition of
00:03:05 --> 00:03:07 resilience. It survived multiple
00:03:07 --> 00:03:10 technical crises that nearly ended the
00:03:10 --> 00:03:12 mission. Yet, the team on the ground
00:03:12 --> 00:03:14 always found a way to bring it back
00:03:14 --> 00:03:15 online.
00:03:15 --> 00:03:18 >> Right. And its contributions have been
00:03:18 --> 00:03:20 monumental. SOHO completely
00:03:20 --> 00:03:23 revolutionized solar science and our
00:03:23 --> 00:03:25 understanding of space weather. The
00:03:25 --> 00:03:28 images and data it provides are the
00:03:28 --> 00:03:31 foundation of modern solar forecasting,
00:03:31 --> 00:03:33 which is critical for protecting our
00:03:33 --> 00:03:35 satellites and power grids.
00:03:35 --> 00:03:37 >> Absolutely. But it has another
00:03:37 --> 00:03:40 completely unexpected legacy, doesn't
00:03:40 --> 00:03:42 it? For a satellite designed to look at
00:03:42 --> 00:03:45 the sun, it's found an incredible number
00:03:45 --> 00:03:48 of comets. It's the most prolific comet
00:03:48 --> 00:03:50 hunter in history, and it's not even
00:03:50 --> 00:03:51 close.
00:03:51 --> 00:03:53 >> Is it a case of being in the right place
00:03:53 --> 00:03:55 at the right time, or is there another
00:03:55 --> 00:03:57 reason why it's so prolific?
00:03:57 --> 00:03:59 >> It's because of its wide, uninterrupted
00:03:59 --> 00:04:02 view of the sun's corona. It spots
00:04:02 --> 00:04:05 so-called sungrazing comets that are
00:04:05 --> 00:04:07 otherwise invisible to us. As of this
00:04:08 --> 00:04:11 year, the official count is over 5
00:04:11 --> 00:04:13 comets discovered by SOHO.
00:04:13 --> 00:04:16 >> That's just amazing. 5 comments as a
00:04:16 --> 00:04:19 side project. SOHO is a true workhorse
00:04:19 --> 00:04:22 of space exploration and a testament to
00:04:22 --> 00:04:24 brilliant engineering.
00:04:24 --> 00:04:26 >> Speaking of brilliant engineering, our
00:04:26 --> 00:04:28 next story looks at the future of
00:04:28 --> 00:04:31 getting around the solar system. Avery,
00:04:31 --> 00:04:34 artificial intelligence is starting to
00:04:34 --> 00:04:36 fundamentally change how we design and
00:04:36 --> 00:04:39 operate spacecraft propulsion systems.
00:04:39 --> 00:04:41 >> This is fascinating stuff. It's not just
00:04:41 --> 00:04:44 about AI pilots like in the movies. This
00:04:44 --> 00:04:46 is about AI making the engines
00:04:46 --> 00:04:49 themselves smarter and more efficient.
00:04:49 --> 00:04:52 >> That's the core of it. Researchers are
00:04:52 --> 00:04:54 using a technique called reinforcement
00:04:54 --> 00:04:57 learning where an AI runs millions of
00:04:57 --> 00:04:59 simulations to discover the most
00:04:59 --> 00:05:01 efficient ways to operate an engine,
00:05:01 --> 00:05:03 often finding solutions that a human
00:05:04 --> 00:05:07 engineer might never think of.
00:05:07 --> 00:05:09 >> So, what kind of advanced systems are
00:05:09 --> 00:05:11 benefiting from this?
00:05:11 --> 00:05:13 We're seeing it applied to next
00:05:13 --> 00:05:16 generation concepts like nuclear thermal
00:05:16 --> 00:05:18 propulsion, both fision and the more
00:05:18 --> 00:05:21 complex fusionbased designs. These
00:05:21 --> 00:05:24 engines are incredibly powerful, but
00:05:24 --> 00:05:27 also incredibly complex to manage.
00:05:28 --> 00:05:30 >> So just what can AI help with? A lot, I
00:05:30 --> 00:05:31 would imagine.
00:05:31 --> 00:05:34 >> AI can optimize the fuel flow,
00:05:34 --> 00:05:37 temperature, and thrust in real time.
00:05:37 --> 00:05:39 It's also being used to tackle one of
00:05:39 --> 00:05:41 the biggest challenges in fusion
00:05:41 --> 00:05:44 research, managing the superheated
00:05:44 --> 00:05:47 plasma. In concepts like the poly well,
00:05:47 --> 00:05:50 a compact fusion device, AI is learning
00:05:50 --> 00:05:52 how to best configure the magnetic
00:05:52 --> 00:05:55 fields to confine the plasma, which is a
00:05:55 --> 00:05:57 massive step forward.
00:05:57 --> 00:06:00 >> So AI is becoming a design partner. It's
00:06:00 --> 00:06:02 not just running the machine, it's
00:06:02 --> 00:06:04 helping to perfect the machine's very
00:06:04 --> 00:06:06 operation. This could be the key to
00:06:06 --> 00:06:08 unlocking faster, more efficient travel
00:06:08 --> 00:06:10 across the solar system.
00:06:10 --> 00:06:12 >> We'll keep an eye on this and report
00:06:12 --> 00:06:15 back on any developments, but it sounds
00:06:15 --> 00:06:16 exciting.
00:06:16 --> 00:06:19 >> From the digital frontier of AI, we go
00:06:19 --> 00:06:22 to something that sounds decidedly more
00:06:22 --> 00:06:26 analog. Anna, what is a hypersonic space
00:06:26 --> 00:06:27 gun?
00:06:27 --> 00:06:29 >> It sounds like something out of Jules
00:06:29 --> 00:06:31 Vern novel, doesn't it? But it's a very
00:06:32 --> 00:06:34 real concept being developed by a
00:06:34 --> 00:06:35 company called Longshot Space
00:06:35 --> 00:06:38 Technologies. They are building a
00:06:38 --> 00:06:41 kinetic space launch system. In simple
00:06:41 --> 00:06:44 terms, it's a massive gun designed to
00:06:44 --> 00:06:47 fire payloads directly into orbit.
00:06:47 --> 00:06:50 >> You're kidding. How does that even work?
00:06:50 --> 00:06:53 >> The system uses a huge piston driven by
00:06:53 --> 00:06:56 compressed gas to launch a projectile at
00:06:56 --> 00:07:00 incredible speeds. We're talking Mach 23
00:07:00 --> 00:07:03 or about 28
00:07:03 --> 00:07:07 km hour. The projectile would carry a
00:07:07 --> 00:07:10 small hardened satellite or other cargo.
00:07:10 --> 00:07:13 >> I can't even imagine the forces
00:07:13 --> 00:07:15 involved. The heat and the acceleration
00:07:15 --> 00:07:17 must be astronomical.
00:07:17 --> 00:07:20 >> They are. That's the biggest challenge.
00:07:20 --> 00:07:22 The payload would experience about
00:07:22 --> 00:07:26 10 gs of acceleration and intense
00:07:26 --> 00:07:29 atmospheric heating. So this isn't for
00:07:29 --> 00:07:31 launching astronauts or delicate
00:07:31 --> 00:07:33 telescopes.
00:07:33 --> 00:07:35 >> Definitely not. So it's for hardened
00:07:36 --> 00:07:37 cargo only.
00:07:37 --> 00:07:40 >> Exactly. Things like fuel, water,
00:07:40 --> 00:07:42 building materials, or ruggedized
00:07:42 --> 00:07:44 military satellites. But here's the
00:07:44 --> 00:07:47 payoff. Longot believes they can get the
00:07:47 --> 00:07:50 cost of launching a kilogram of cargo to
00:07:50 --> 00:07:52 just $10.
00:07:52 --> 00:07:54 >> $10. That's compared to thousands of
00:07:54 --> 00:07:56 dollars per kilogram on a traditional
00:07:56 --> 00:07:59 rocket. That's a complete gamecher for
00:07:59 --> 00:08:00 space logistics.
00:08:00 --> 00:08:03 >> It is. And that's why it's attracting
00:08:03 --> 00:08:05 serious interest from both venture
00:08:05 --> 00:08:08 capital and military agencies. If they
00:08:08 --> 00:08:10 can solve the engineering challenges,
00:08:10 --> 00:08:13 this space gun could revolutionize how
00:08:13 --> 00:08:16 we supply future operations in orbit and
00:08:16 --> 00:08:17 beyond.
00:08:17 --> 00:08:19 >> All right, let's bring our focus back to
00:08:19 --> 00:08:21 our own night sky. For all our
00:08:21 --> 00:08:23 stargazing listeners out there, one of
00:08:23 --> 00:08:25 the best celestial shows of the year is
00:08:25 --> 00:08:27 just around the corner.
00:08:27 --> 00:08:30 >> That's right. The Gemini meteor shower
00:08:30 --> 00:08:32 is set to peak on the night of December
00:08:32 --> 00:08:35 13th into the morning of the 14th. And
00:08:35 --> 00:08:37 this year, the conditions are just about
00:08:37 --> 00:08:39 perfect.
00:08:39 --> 00:08:41 >> What makes this year so good?
00:08:41 --> 00:08:44 >> The moon. It will be a waning crescent,
00:08:44 --> 00:08:46 which means it won't rise until the
00:08:46 --> 00:08:48 early hours of the morning, and its
00:08:48 --> 00:08:50 light won't wash out the fainter
00:08:50 --> 00:08:52 meteors. We'll have beautifully dark
00:08:52 --> 00:08:54 skies for most of the night.
00:08:54 --> 00:08:57 >> Fantastic. So, what can people expect to
00:08:57 --> 00:08:59 see?
00:08:59 --> 00:09:01 >> Under ideal conditions, you could see
00:09:01 --> 00:09:05 between 120 and 150 meteors per hour at
00:09:05 --> 00:09:08 the peak. The radiant, the point they
00:09:08 --> 00:09:10 appear to come from, is near the star
00:09:10 --> 00:09:14 castor in the constellation Gemini.
00:09:14 --> 00:09:16 >> And Geminites are known for being a bit
00:09:16 --> 00:09:18 slower, right? It makes them easier to
00:09:18 --> 00:09:19 spot.
00:09:19 --> 00:09:22 >> Yes, they enter the atmosphere at about
00:09:22 --> 00:09:25 22 m per second. That sounds fast, but
00:09:25 --> 00:09:27 it's slower than many other showers,
00:09:27 --> 00:09:30 which can lead to longer, more graceful
00:09:30 --> 00:09:33 streaks across the sky. They are also
00:09:33 --> 00:09:34 often brightly colored
00:09:34 --> 00:09:36 >> and they have a really interesting
00:09:36 --> 00:09:37 origin.
00:09:37 --> 00:09:39 >> They do. Unlike most meteor showers
00:09:40 --> 00:09:42 which come from the debris trail of a
00:09:42 --> 00:09:44 comet, the Geminids originate from an
00:09:44 --> 00:09:48 asteroid called 3200 Faithon. It's a bit
00:09:48 --> 00:09:50 of a mystery how this rocky body
00:09:50 --> 00:09:52 produces so much debris.
00:09:52 --> 00:09:54 >> So what are your tips for viewers?
00:09:54 --> 00:09:57 >> Find a location away from city lights.
00:09:57 --> 00:10:00 Dress warmly, lie back on a blanket or a
00:10:00 --> 00:10:03 chair, and just look up. You don't need
00:10:03 --> 00:10:06 a telescope or binoculars. Just give
00:10:06 --> 00:10:08 your eyes about 20 minutes to fully
00:10:08 --> 00:10:11 adapt to the dark and enjoy the show.
00:10:11 --> 00:10:13 And for our final story today, we are
00:10:13 --> 00:10:15 revisiting a cold case from the outer
00:10:15 --> 00:10:18 solar system and solving a mystery
00:10:18 --> 00:10:20 that's nearly four decades old.
00:10:20 --> 00:10:23 >> This has to be about Voyager 2's flyby
00:10:23 --> 00:10:26 of Uranus in 1986. I remember reading
00:10:26 --> 00:10:29 that it found something unexpected in
00:10:29 --> 00:10:31 the planet's radiation belts.
00:10:31 --> 00:10:33 >> That's the one. Voyager 2 detected an
00:10:34 --> 00:10:36 incredibly intense belt of high energy
00:10:36 --> 00:10:39 electron radiation, far more powerful
00:10:39 --> 00:10:42 than models had predicted. For decades,
00:10:42 --> 00:10:44 scientists couldn't quite explain why it
00:10:44 --> 00:10:45 was so strong.
00:10:45 --> 00:10:48 >> And after all this time, there's a new
00:10:48 --> 00:10:48 explanation.
00:10:48 --> 00:10:51 >> There is. A team at the Southwest
00:10:51 --> 00:10:53 Research Institute revisited the old
00:10:54 --> 00:10:56 Voyager data. They proposed the intense
00:10:56 --> 00:10:59 radiation wasn't caused by Uranus alone.
00:10:59 --> 00:11:02 Instead, it was a case of being in the
00:11:02 --> 00:11:04 right place at the right time.
00:11:04 --> 00:11:05 >> So, what was happening?
00:11:06 --> 00:11:08 >> The team believes a huge structure in
00:11:08 --> 00:11:10 the solar wind called a co-rotating
00:11:10 --> 00:11:13 interaction region was passing through
00:11:13 --> 00:11:16 the Uranian system just as Voyager 2
00:11:16 --> 00:11:17 flew by.
00:11:17 --> 00:11:19 >> A co-rotating what? Now,
00:11:19 --> 00:11:21 >> think of it as a massive shock wave in
00:11:21 --> 00:11:23 the solar wind where fast moving solar
00:11:23 --> 00:11:26 particles overtake slower ones. This
00:11:26 --> 00:11:28 interaction creates powerful
00:11:28 --> 00:11:30 highfrequency plasma waves like Whistler
00:11:30 --> 00:11:33 waves. These waves were the perfect
00:11:33 --> 00:11:35 frequency to grab electrons already
00:11:35 --> 00:11:37 trapped in Uranus's magnetic field and
00:11:38 --> 00:11:40 accelerate them to incredible speeds,
00:11:40 --> 00:11:42 creating that intense radiation belt
00:11:42 --> 00:11:45 Voyager saw. We see similar events
00:11:45 --> 00:11:48 happen near Earth, but this is the first
00:11:48 --> 00:11:50 time we've confirmed it happening so far
00:11:50 --> 00:11:51 out in the solar system.
00:11:51 --> 00:11:54 >> So, it was a temporary storm caused by
00:11:54 --> 00:11:56 the sun that Voyager just happened to
00:11:56 --> 00:11:59 fly through. That is a brilliant piece
00:11:59 --> 00:12:01 of cosmic detective work.
00:12:01 --> 00:12:01 >> You betcha.
00:12:01 --> 00:12:04 >> And that's a wrap. From mysterious
00:12:04 --> 00:12:06 interstellar visitors and hypersonic
00:12:06 --> 00:12:08 cannons to celebrating a 30-year-old
00:12:08 --> 00:12:12 hero of astronomy and finally solving a
00:12:12 --> 00:12:14 cold case from Uranus. What an episode.
00:12:14 --> 00:12:17 >> It really was. That's all the time we
00:12:17 --> 00:12:19 have for today on Astronomy Daily. We'd
00:12:19 --> 00:12:21 like to thank you all for tuning in.
00:12:21 --> 00:12:23 >> Join us next time as we continue to
00:12:23 --> 00:12:25 explore the wonders of the universe.
00:12:25 --> 00:12:28 Until then, clear skies everyone and
00:12:28 --> 00:12:31 remember to get out there and look up.
00:12:31 --> 00:12:34 Every day
00:12:34 --> 00:12:42 stories we told
00:12:42 --> 00:12:50 stories told
00:12:50 --> 00:12:52 stories