Speaker 1: Welcome to Astronomy Daily.
Speaker 2: I'm Anna and I'm Avery. It's Monday, March ninth, and
if you've been following the news this past week, the
universe has been spectacularly busy.
Speaker 1: We've got alien signals going missing in the cosmic static
astronaut brains getting physically rearranged in space, a dramatic launch
pad rescue stories straight out of a thriller, and a
genuinely mind bending discovery about why Earth seasons work the
way they do.
Speaker 2: LUs we're asking one of astrobiology's most provocative questions, did
life on Earth actually start on Mars? It's a packed episode,
let's get into it.
Speaker 1: Here's a thought that's going to sit with you for
a while. What if we're not alone in the universe,
but we've been tuning to the wrong frequency this whole time.
Speaker 2: That's essentially what a new study from SETI is suggesting.
Researchers Vishal Goadjar and Grace Brown have published work showing
that stellar space weather, the kind of turbulent plasma and
solar activity that stars constantly turn out, could physically distort
alien radio signals before they even leave their home solar system.
Speaker 1: So here's how SETI searches typically work. For decades, scientists
have been scanning the sky for very tightly focused, narrow
band radio signals, extremely specific frequencies that nothing natural in
the universe should produce. If you detect one of those,
the thinking goes, it's almost certainly artificial, it's almost certainly someone.
Speaker 2: And that logic is still sound. But the new research
highlights a gap in the reasoning. Even if an alien
civilization sense a perfectly clean narrowband signal, their own stars,
environment might smear it out before it escapes plasma density,
Fluctuations in stellar winds or a burst from a coronal
mass ejection can spread that tight signal across a much
wider range of frequencies, reducing its strength that any single
point below what our detectors can pick up.
Speaker 1: The team ran simulations of the billion closest sunlike and
red dwarf stars and found that seventy percent of stars
would broaden a signal by more than one hurtz, thirty
percent by more than ten herts, and if a coronal
mass ejection happened to fire off at the moment of transmission,
the broadening could exceed one thousand herts, making the signal
essentially invisible to the way we currently search and Red.
Speaker 2: Dwarf stars are the biggest culprits here, and that's particularly
significant because red dwarfs make up about three quarters of
all the stars in the Milky Way. A lot of
our SETI attention has focused on those systems precisely because
they're so common, and it turns out they may also
be the most likely to garble any messages being sent
from their planets.
Speaker 1: The good news is that identifying the problem is the
first step to solving it. The team says this gives
us a framework for redesigning searches to remain sensitive even
one signals are broadened to look for what actually arrives
at Earth rather than what was originally transmitted.
Speaker 2: It's a bit like realizing you've been trying to tune
into a radio spation, but the signal had passed through
a foggy atmosphere on its way to you. It's not
that the station isn't broadcasting, it's that we need a
better aerial and that's.
Speaker 1: A much more hopeful framing than nobody's out there. The
universe might be full of voices, we just haven't learned
to hear yet.
Speaker 2: Now, if you're planning a trip to space, or if
you're just a big Artemis fan, this next story is
worth paying attention to, though we want to say upfront
that it's fascinating rather than alarming.
Speaker 1: A new study published in the Proceedings of the National
Academy of Sciences has found that spaceflight doesn't just change
your perspective on life, it literally shifts the physical position
of your brain inside your skull.
Speaker 2: A team led by Rachel Seidler at the University of
Florida analyzed MRI scans from twenty six astronauts taken before
and after missions to the ISS missions ranging from a
few weeks to over a year, to measure the brain's
actual movement. They aligned each person's skull across the two
scans so they could track the brain's position relative to
the bone itself.
Speaker 1: And what they found was striking. The brain shifts upward
and backward inside the skull. It also physically deforms, stretching
and compressing in different directions. The sensory and motor regions
show the largest shifts, and crucially, the longer someone spent
in space, the more pronounced these changes were.
Speaker 2: The underlying cause is what you'd expect from microgravity on Earth.
Gravity constantly pulls fluids, including the cerebral spinal fluid surrounding
your brain, downward. In space, that force disappears fluid redistributes
towards the head. The brain effectively floats in the skull,
and it responds to different forces from surrounding tissues.
Speaker 1: Previous research already knew the brain shifts upward in space.
What makes this study important is the level of detail.
Instead of treating the brain as one object, the team
divided it into more than one hundred regions and tracked
each individually. That revealed patterns like opposing lateral shifts on
each side of the brain that had been canceling each
other out and going unnoticed in whole brain averages.
Speaker 2: The reassuring news most of the changes recover within six
months of returning to Earth, and the astronauts themselves didn't
report symptoms like headaches or cognitive fog. The researcher stressed
that this doesn't mean people shouldn't go to space, but
as missions get longer and as Artemis starts taking humans
back to the Moon and eventually towards Mars, understanding these
effects will be important for designing proper countermeasures.
Speaker 1: It's a reminder that space is a genuinely alien environment
for the human body. We evolved under one gravity, and
every time we leave it, we're running an experiment on ourselves.
The more we understand those experiments, the safer we can
make long duration spaceflight.
Speaker 2: Now for a story that is, in the best possible way,
a bit of a thriller. In November last year, something
went wrong at the historic bikan Or Cosmodrome in Kazakhstan,
and nobody was entirely sure it could be fixed in time.
Speaker 1: It started. On November twenty seventh, twenty twenty five, a
Soyuz rocket lifted off from launch Site thirty one, carrying
the Soyuz MS twenty eight spacecraft, with two Rose Cosmos
cosmonauts and NASA astronaut Christopher Williams aboard. The launch was successful.
The crew docked with the ISS without incident.
Speaker 2: But post launch inspection footage revealed significant damage to the
pad itself. A component called the service cabin, which retracts
into a protective cavity to shield it from engine exhausting ascent,
hadn't been properly secured. The powerful rocket exhaust dislodged it
and the structure fell several meters into the launch trench,
deforming bridges, access walkways and other critical infrastructure.
Speaker 1: The space community was skeptical this could be fixed quickly.
These are heavy, complex structures, but Rose Cosmos committed to
the repair, and it turns out their long history with
the soyuse system gave them an unexpected advantage. Bear service
cabins had been sitting in storage leftover from refurbishment plans
dating back to the nineteen seventies.
Speaker 2: The restoration effort was enormous. Over one hundred and fifty
personnel worked on the project. They completed over two hundred
and fifty meters of welding, painted nearly twenty four hundred
square meters of structures, replaced all fastening units, and fully
updated the electrical systems. The replacement cabin, originally built for
an older SOYZ variant, needed modifications to work with modern hardware.
Speaker 1: And in under two months from the initial damage assessment,
far faster than most observers anticipated, Rose Cosmos announced the
pad was fully restored and declared ready for operations.
Speaker 2: That means progress MS thirty three and uncrewed cargo ship
is now cleared to launch from Site thirty one on
March twenty second. It will deliver around two point five
tons of supplies to the ISA propellants, water, food, scientific equipment,
and crew parcels.
Speaker 1: It's a genuinely impressive piece of engineering under pressure, and
it's a good reminder that behind every rocket launch is
an enormous amount of groundwork literally in this case, that
never makes headlines until something goes sideways.
Speaker 2: Okay, pop quiz. Why do we have seasons?
Speaker 1: Earth's axial tilt. We all learned this in school. When
the northern hemisphere is tilted toward the Sun, it's summer
up here. When it's tilted away, it's winter.
Speaker 2: Exactly right. And most people also know that Earth's orbit
around the Sun is slightly elliptical. We're a bit closer
to the Sun in January and a bit farther away
in July. But we're usually told that effect is minor
and it doesn't significantly change our seasons. Well, a new
study published in Nature suggests we may have been under
selling that distance effect quite significantly.
Speaker 1: The research, led by John Chiang at UC Berkeley, focuses
on a specific feature of the Pacific Ocean called the
cold Tongue, a strip of cooler water that stretches westward
from South America along the equator. This cold tongue is
closely tied to Almino and La a Ninia cycles, which
influence rainfall, drought, and weather patterns across huge swaths of
the planet.
Speaker 2: What Chang and his colleagues found is that the changing
Earth sun distance creates its own separate annual cycle in
the cold tongue, distinct from the tilt driven one, and
the two cycles are slightly out of sync. The distance
based one runs about twenty five minutes longer than the
tilt based one. That doesn't sound like much, but it
means that over about eleven thousand years, the two effects
drift from being perfectly in phase to perfectly out of phase.
Speaker 1: When they're in phase like they are roughly today, the
effects reinforce each other. When they're out of phase, as
they were around six thousand years ago, they partially cancel,
producing a much weaker seasonal cycle in the cold tongue.
And since the cold tongue drives el Nino, that means
el Nino patterns themselves would have been dramatically different in
the deep past.
Speaker 2: The mechanism works in a counterintuitive direction too. While axial
tilt creates north south temperature differences, the distance effect creates
an east west contrast between the continental hemisphere of the
America's Africa and Eurasia and the ocean dominated Pacific side.
That contrast drives trade winds, which in turn shape the
cold tongue.
Speaker 1: It's worth noting the study is entirely model based. It's
a prediction that will need observational verification, but it opens
fascinating questions for paleoclimate science. If Earth's orbital shape was
changing the cold tongue over twenty two thousand year cycles,
some ancient climate records may need reinterpretation.
Speaker 2: And there's something wonderfully humbling about it. We've been telling
school children for generations exactly why seasons have happen, and
it turns out the full picture involves a subtle cosmic
clockwork we hadn't fully accounted for.
Speaker 1: And now for our final story today and honestly, one
of the most mind bending things you can contemplate on
a Monday, what if you're not from Earth?
Speaker 2: In a very literal biological sense.
Speaker 1: Possibly a new study is revisiting the concept of panspermia,
the idea that life doesn't necessarily originate independently on each planet,
but can travel between worlds and the vehicle asteroid impacts.
Speaker 2: Here's the premis. We know that when a large asteroid
or comet slams into a planet within a force, it
can blast material into space, rocks, dust, and potentially anything
living inside those rocks. We've actually found meteorites on Earth
that originated on Mars, blasted off by ancient impacts, so
the physical pathway definitely exists.
Speaker 1: The question has always been could anything survive that journey?
You're talking about the ejection itself, an enormous shockwave, then
exposure to the vacuum and radiation of space for potentially
millions of years, then a fiery atmospheric entry and high
speed impact at the destination.
Speaker 2: The new research suggests the answer might be yes. Under
the right conditions, some microbes, particularly those that form hardy
spores or live deep within rocks, could potentially survive all
of those stages. The rock itself provides shielding from radiation
during transit, and the numbers game matters. Even if only
a tiny fraction of ejected material survives, the sheer volume
of material blasted around the early Solar system means some
viable biology could have made the crossing.
Speaker 1: The Mars connection is particularly intriguing. Early Mars was, by
many accounts a better candidate for life to emerge first
than early Earth. It cooled faster, it had liquid water earlier,
and it had a gentler gravitational well, making it easier
for material to escape. If life arose on Mars billions
of years ago and hitched a ride on an impact
ejected rock, Earth could effectively have been seated.
Speaker 2: Which would mean that if we ever find microbial life
on Mars or evidence of ancient life there, we'd face
a fascinating interpretive challenge. Did life arise independently on both
worlds or are we all in some deep ancestral sense Martians.
Speaker 1: The study emphasizes this is still highly speculative, hence bermia
remains a hypothesis rather than established science, But as our
ability to study Martian samples improves, especially with future sample
return missions, we may eventually be in a position to
test it directly.
Speaker 2: Either way, the question is deeply fascinating, and it gives
a whole new flavor to the phrase out of this world.
Speaker 1: That's Astronomy Daily from Monday, March ninth. From scrambled alien
signals to astronaut brains, from a launchpad resurrection, to the
hidden clockwork of Earth seasons and the possibility that we're
all secretly from Mars.
Speaker 2: It's been a great episode. If you're enjoying the show,
please leave us a review. Wherever you listen. It genuinely
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Speaker 2: We'll be back tomorrow with more of the Universe's greatest hits.
Until then, keep looking up.
Speaker 1: Bye for now, Sunday.
Speaker 2: Starsz. Starz