Are We Missing Alien Signals? Space Weather, Brain Changes and the Mars Life Question

0:00 Speaker 1: Welcome to Astronomy Daily.

0:02 Speaker 2: I'm Anna and I'm Avery. It's Monday, March ninth, and

0:06 Speaker 2: if you've been following the news this past week, the

0:08 Speaker 2: universe has been spectacularly busy.

0:11 Speaker 1: We've got alien signals going missing in the cosmic static

0:15 Speaker 1: astronaut brains getting physically rearranged in space, a dramatic launch

0:20 Speaker 1: pad rescue stories straight out of a thriller, and a

0:23 Speaker 1: genuinely mind bending discovery about why Earth seasons work the

0:27 Speaker 1: way they do.

0:29 Speaker 2: LUs we're asking one of astrobiology's most provocative questions, did

0:33 Speaker 2: life on Earth actually start on Mars? It's a packed episode,

0:37 Speaker 2: let's get into it.

0:38 Speaker 1: Here's a thought that's going to sit with you for

0:40 Speaker 1: a while. What if we're not alone in the universe,

0:43 Speaker 1: but we've been tuning to the wrong frequency this whole time.

0:47 Speaker 2: That's essentially what a new study from SETI is suggesting.

0:51 Speaker 2: Researchers Vishal Goadjar and Grace Brown have published work showing

0:55 Speaker 2: that stellar space weather, the kind of turbulent plasma and

0:59 Speaker 2: solar activity that stars constantly turn out, could physically distort

1:03 Speaker 2: alien radio signals before they even leave their home solar system.

1:07 Speaker 1: So here's how SETI searches typically work. For decades, scientists

1:12 Speaker 1: have been scanning the sky for very tightly focused, narrow

1:15 Speaker 1: band radio signals, extremely specific frequencies that nothing natural in

1:20 Speaker 1: the universe should produce. If you detect one of those,

1:24 Speaker 1: the thinking goes, it's almost certainly artificial, it's almost certainly someone.

1:29 Speaker 2: And that logic is still sound. But the new research

1:32 Speaker 2: highlights a gap in the reasoning. Even if an alien

1:35 Speaker 2: civilization sense a perfectly clean narrowband signal, their own stars,

1:40 Speaker 2: environment might smear it out before it escapes plasma density,

1:44 Speaker 2: Fluctuations in stellar winds or a burst from a coronal

1:47 Speaker 2: mass ejection can spread that tight signal across a much

1:51 Speaker 2: wider range of frequencies, reducing its strength that any single

1:55 Speaker 2: point below what our detectors can pick up.

1:58 Speaker 1: The team ran simulations of the billion closest sunlike and

2:01 Speaker 1: red dwarf stars and found that seventy percent of stars

2:05 Speaker 1: would broaden a signal by more than one hurtz, thirty

2:08 Speaker 1: percent by more than ten herts, and if a coronal

2:11 Speaker 1: mass ejection happened to fire off at the moment of transmission,

2:15 Speaker 1: the broadening could exceed one thousand herts, making the signal

2:19 Speaker 1: essentially invisible to the way we currently search and Red.

2:23 Speaker 2: Dwarf stars are the biggest culprits here, and that's particularly

2:26 Speaker 2: significant because red dwarfs make up about three quarters of

2:30 Speaker 2: all the stars in the Milky Way. A lot of

2:32 Speaker 2: our SETI attention has focused on those systems precisely because

2:36 Speaker 2: they're so common, and it turns out they may also

2:39 Speaker 2: be the most likely to garble any messages being sent

2:42 Speaker 2: from their planets.

2:43 Speaker 1: The good news is that identifying the problem is the

2:46 Speaker 1: first step to solving it. The team says this gives

2:49 Speaker 1: us a framework for redesigning searches to remain sensitive even

2:54 Speaker 1: one signals are broadened to look for what actually arrives

2:57 Speaker 1: at Earth rather than what was originally transmitted.

3:01 Speaker 2: It's a bit like realizing you've been trying to tune

3:03 Speaker 2: into a radio spation, but the signal had passed through

3:06 Speaker 2: a foggy atmosphere on its way to you. It's not

3:09 Speaker 2: that the station isn't broadcasting, it's that we need a

3:12 Speaker 2: better aerial and that's.

3:13 Speaker 1: A much more hopeful framing than nobody's out there. The

3:17 Speaker 1: universe might be full of voices, we just haven't learned

3:20 Speaker 1: to hear yet.

3:21 Speaker 2: Now, if you're planning a trip to space, or if

3:23 Speaker 2: you're just a big Artemis fan, this next story is

3:26 Speaker 2: worth paying attention to, though we want to say upfront

3:29 Speaker 2: that it's fascinating rather than alarming.

3:31 Speaker 1: A new study published in the Proceedings of the National

3:34 Speaker 1: Academy of Sciences has found that spaceflight doesn't just change

3:38 Speaker 1: your perspective on life, it literally shifts the physical position

3:42 Speaker 1: of your brain inside your skull.

3:45 Speaker 2: A team led by Rachel Seidler at the University of

3:48 Speaker 2: Florida analyzed MRI scans from twenty six astronauts taken before

3:53 Speaker 2: and after missions to the ISS missions ranging from a

3:56 Speaker 2: few weeks to over a year, to measure the brain's

4:00 Speaker 2: actual movement. They aligned each person's skull across the two

4:04 Speaker 2: scans so they could track the brain's position relative to

4:07 Speaker 2: the bone itself.

4:09 Speaker 1: And what they found was striking. The brain shifts upward

4:13 Speaker 1: and backward inside the skull. It also physically deforms, stretching

4:17 Speaker 1: and compressing in different directions. The sensory and motor regions

4:21 Speaker 1: show the largest shifts, and crucially, the longer someone spent

4:25 Speaker 1: in space, the more pronounced these changes were.

4:28 Speaker 2: The underlying cause is what you'd expect from microgravity on Earth.

4:33 Speaker 2: Gravity constantly pulls fluids, including the cerebral spinal fluid surrounding

4:37 Speaker 2: your brain, downward. In space, that force disappears fluid redistributes

4:43 Speaker 2: towards the head. The brain effectively floats in the skull,

4:46 Speaker 2: and it responds to different forces from surrounding tissues.

4:49 Speaker 1: Previous research already knew the brain shifts upward in space.

4:53 Speaker 1: What makes this study important is the level of detail.

4:56 Speaker 1: Instead of treating the brain as one object, the team

4:59 Speaker 1: divided it into more than one hundred regions and tracked

5:02 Speaker 1: each individually. That revealed patterns like opposing lateral shifts on

5:07 Speaker 1: each side of the brain that had been canceling each

5:09 Speaker 1: other out and going unnoticed in whole brain averages.

5:13 Speaker 2: The reassuring news most of the changes recover within six

5:17 Speaker 2: months of returning to Earth, and the astronauts themselves didn't

5:21 Speaker 2: report symptoms like headaches or cognitive fog. The researcher stressed

5:25 Speaker 2: that this doesn't mean people shouldn't go to space, but

5:28 Speaker 2: as missions get longer and as Artemis starts taking humans

5:31 Speaker 2: back to the Moon and eventually towards Mars, understanding these

5:35 Speaker 2: effects will be important for designing proper countermeasures.

5:39 Speaker 1: It's a reminder that space is a genuinely alien environment

5:42 Speaker 1: for the human body. We evolved under one gravity, and

5:46 Speaker 1: every time we leave it, we're running an experiment on ourselves.

5:49 Speaker 1: The more we understand those experiments, the safer we can

5:52 Speaker 1: make long duration spaceflight.

5:54 Speaker 2: Now for a story that is, in the best possible way,

5:57 Speaker 2: a bit of a thriller. In November last year, something

6:01 Speaker 2: went wrong at the historic bikan Or Cosmodrome in Kazakhstan,

6:05 Speaker 2: and nobody was entirely sure it could be fixed in time.

6:08 Speaker 1: It started. On November twenty seventh, twenty twenty five, a

6:12 Speaker 1: Soyuz rocket lifted off from launch Site thirty one, carrying

6:15 Speaker 1: the Soyuz MS twenty eight spacecraft, with two Rose Cosmos

6:19 Speaker 1: cosmonauts and NASA astronaut Christopher Williams aboard. The launch was successful.

6:24 Speaker 1: The crew docked with the ISS without incident.

6:27 Speaker 2: But post launch inspection footage revealed significant damage to the

6:31 Speaker 2: pad itself. A component called the service cabin, which retracts

6:35 Speaker 2: into a protective cavity to shield it from engine exhausting ascent,

6:39 Speaker 2: hadn't been properly secured. The powerful rocket exhaust dislodged it

6:43 Speaker 2: and the structure fell several meters into the launch trench,

6:47 Speaker 2: deforming bridges, access walkways and other critical infrastructure.

6:51 Speaker 1: The space community was skeptical this could be fixed quickly.

6:55 Speaker 1: These are heavy, complex structures, but Rose Cosmos committed to

6:59 Speaker 1: the repair, and it turns out their long history with

7:02 Speaker 1: the soyuse system gave them an unexpected advantage. Bear service

7:06 Speaker 1: cabins had been sitting in storage leftover from refurbishment plans

7:09 Speaker 1: dating back to the nineteen seventies.

7:12 Speaker 2: The restoration effort was enormous. Over one hundred and fifty

7:16 Speaker 2: personnel worked on the project. They completed over two hundred

7:19 Speaker 2: and fifty meters of welding, painted nearly twenty four hundred

7:23 Speaker 2: square meters of structures, replaced all fastening units, and fully

7:27 Speaker 2: updated the electrical systems. The replacement cabin, originally built for

7:31 Speaker 2: an older SOYZ variant, needed modifications to work with modern hardware.

7:36 Speaker 1: And in under two months from the initial damage assessment,

7:39 Speaker 1: far faster than most observers anticipated, Rose Cosmos announced the

7:43 Speaker 1: pad was fully restored and declared ready for operations.

7:47 Speaker 2: That means progress MS thirty three and uncrewed cargo ship

7:51 Speaker 2: is now cleared to launch from Site thirty one on

7:54 Speaker 2: March twenty second. It will deliver around two point five

7:58 Speaker 2: tons of supplies to the ISA propellants, water, food, scientific equipment,

8:04 Speaker 2: and crew parcels.

8:06 Speaker 1: It's a genuinely impressive piece of engineering under pressure, and

8:10 Speaker 1: it's a good reminder that behind every rocket launch is

8:13 Speaker 1: an enormous amount of groundwork literally in this case, that

8:17 Speaker 1: never makes headlines until something goes sideways.

8:20 Speaker 2: Okay, pop quiz. Why do we have seasons?

8:24 Speaker 1: Earth's axial tilt. We all learned this in school. When

8:27 Speaker 1: the northern hemisphere is tilted toward the Sun, it's summer

8:30 Speaker 1: up here. When it's tilted away, it's winter.

8:33 Speaker 2: Exactly right. And most people also know that Earth's orbit

8:37 Speaker 2: around the Sun is slightly elliptical. We're a bit closer

8:40 Speaker 2: to the Sun in January and a bit farther away

8:43 Speaker 2: in July. But we're usually told that effect is minor

8:46 Speaker 2: and it doesn't significantly change our seasons. Well, a new

8:51 Speaker 2: study published in Nature suggests we may have been under

8:54 Speaker 2: selling that distance effect quite significantly.

8:57 Speaker 1: The research, led by John Chiang at UC Berkeley, focuses

9:01 Speaker 1: on a specific feature of the Pacific Ocean called the

9:04 Speaker 1: cold Tongue, a strip of cooler water that stretches westward

9:07 Speaker 1: from South America along the equator. This cold tongue is

9:11 Speaker 1: closely tied to Almino and La a Ninia cycles, which

9:14 Speaker 1: influence rainfall, drought, and weather patterns across huge swaths of

9:19 Speaker 1: the planet.

9:20 Speaker 2: What Chang and his colleagues found is that the changing

9:23 Speaker 2: Earth sun distance creates its own separate annual cycle in

9:27 Speaker 2: the cold tongue, distinct from the tilt driven one, and

9:30 Speaker 2: the two cycles are slightly out of sync. The distance

9:33 Speaker 2: based one runs about twenty five minutes longer than the

9:37 Speaker 2: tilt based one. That doesn't sound like much, but it

9:40 Speaker 2: means that over about eleven thousand years, the two effects

9:44 Speaker 2: drift from being perfectly in phase to perfectly out of phase.

9:48 Speaker 1: When they're in phase like they are roughly today, the

9:51 Speaker 1: effects reinforce each other. When they're out of phase, as

9:54 Speaker 1: they were around six thousand years ago, they partially cancel,

9:58 Speaker 1: producing a much weaker seasonal cycle in the cold tongue.

10:02 Speaker 1: And since the cold tongue drives el Nino, that means

10:05 Speaker 1: el Nino patterns themselves would have been dramatically different in

10:08 Speaker 1: the deep past.

10:10 Speaker 2: The mechanism works in a counterintuitive direction too. While axial

10:14 Speaker 2: tilt creates north south temperature differences, the distance effect creates

10:19 Speaker 2: an east west contrast between the continental hemisphere of the

10:23 Speaker 2: America's Africa and Eurasia and the ocean dominated Pacific side.

10:29 Speaker 2: That contrast drives trade winds, which in turn shape the

10:32 Speaker 2: cold tongue.

10:33 Speaker 1: It's worth noting the study is entirely model based. It's

10:37 Speaker 1: a prediction that will need observational verification, but it opens

10:40 Speaker 1: fascinating questions for paleoclimate science. If Earth's orbital shape was

10:45 Speaker 1: changing the cold tongue over twenty two thousand year cycles,

10:49 Speaker 1: some ancient climate records may need reinterpretation.

10:53 Speaker 2: And there's something wonderfully humbling about it. We've been telling

10:56 Speaker 2: school children for generations exactly why seasons have happen, and

11:00 Speaker 2: it turns out the full picture involves a subtle cosmic

11:04 Speaker 2: clockwork we hadn't fully accounted for.

11:07 Speaker 1: And now for our final story today and honestly, one

11:10 Speaker 1: of the most mind bending things you can contemplate on

11:12 Speaker 1: a Monday, what if you're not from Earth?

11:17 Speaker 2: In a very literal biological sense.

11:19 Speaker 1: Possibly a new study is revisiting the concept of panspermia,

11:23 Speaker 1: the idea that life doesn't necessarily originate independently on each planet,

11:28 Speaker 1: but can travel between worlds and the vehicle asteroid impacts.

11:33 Speaker 2: Here's the premis. We know that when a large asteroid

11:36 Speaker 2: or comet slams into a planet within a force, it

11:39 Speaker 2: can blast material into space, rocks, dust, and potentially anything

11:44 Speaker 2: living inside those rocks. We've actually found meteorites on Earth

11:48 Speaker 2: that originated on Mars, blasted off by ancient impacts, so

11:53 Speaker 2: the physical pathway definitely exists.

11:56 Speaker 1: The question has always been could anything survive that journey?

12:00 Speaker 1: You're talking about the ejection itself, an enormous shockwave, then

12:05 Speaker 1: exposure to the vacuum and radiation of space for potentially

12:08 Speaker 1: millions of years, then a fiery atmospheric entry and high

12:13 Speaker 1: speed impact at the destination.

12:15 Speaker 2: The new research suggests the answer might be yes. Under

12:19 Speaker 2: the right conditions, some microbes, particularly those that form hardy

12:22 Speaker 2: spores or live deep within rocks, could potentially survive all

12:26 Speaker 2: of those stages. The rock itself provides shielding from radiation

12:30 Speaker 2: during transit, and the numbers game matters. Even if only

12:34 Speaker 2: a tiny fraction of ejected material survives, the sheer volume

12:37 Speaker 2: of material blasted around the early Solar system means some

12:41 Speaker 2: viable biology could have made the crossing.

12:44 Speaker 1: The Mars connection is particularly intriguing. Early Mars was, by

12:49 Speaker 1: many accounts a better candidate for life to emerge first

12:52 Speaker 1: than early Earth. It cooled faster, it had liquid water earlier,

12:57 Speaker 1: and it had a gentler gravitational well, making it easier

13:01 Speaker 1: for material to escape. If life arose on Mars billions

13:05 Speaker 1: of years ago and hitched a ride on an impact

13:08 Speaker 1: ejected rock, Earth could effectively have been seated.

13:11 Speaker 2: Which would mean that if we ever find microbial life

13:14 Speaker 2: on Mars or evidence of ancient life there, we'd face

13:17 Speaker 2: a fascinating interpretive challenge. Did life arise independently on both

13:22 Speaker 2: worlds or are we all in some deep ancestral sense Martians.

13:27 Speaker 1: The study emphasizes this is still highly speculative, hence bermia

13:32 Speaker 1: remains a hypothesis rather than established science, But as our

13:36 Speaker 1: ability to study Martian samples improves, especially with future sample

13:41 Speaker 1: return missions, we may eventually be in a position to

13:44 Speaker 1: test it directly.

13:46 Speaker 2: Either way, the question is deeply fascinating, and it gives

13:49 Speaker 2: a whole new flavor to the phrase out of this world.

13:53 Speaker 1: That's Astronomy Daily from Monday, March ninth. From scrambled alien

13:57 Speaker 1: signals to astronaut brains, from a launchpad resurrection, to the

14:02 Speaker 1: hidden clockwork of Earth seasons and the possibility that we're

14:06 Speaker 1: all secretly from Mars.

14:08 Speaker 2: It's been a great episode. If you're enjoying the show,

14:11 Speaker 2: please leave us a review. Wherever you listen. It genuinely

14:14 Speaker 2: helps new listeners find us and share an episode with

14:17 Speaker 2: a friend who's curious about the universe.

14:19 Speaker 1: You can find us at Astronomydaily dot io and we're

14:23 Speaker 1: at astro Daily pod on x, Instagram, TikTok, YouTube, and Tumbler.

14:28 Speaker 2: We'll be back tomorrow with more of the Universe's greatest hits.

14:31 Speaker 2: Until then, keep looking up.

14:33 Speaker 1: Bye for now, Sunday.

14:37 Speaker 2: Starsz. Starz