Speaker 1: Hello, and welcome to Astronomy Daily. I'm Anna and I'm Avery.
Speaker 2: You've joined us on a very eventful day for space fans, Tuesday,
the tenth of March twenty twenty six, and the universe
is not holding back.
Speaker 1: We genuinely mean that we have a satellite falling out
of the sky today, a meteorite that crashed through someone's
roof over the weekend, Congress picking a fight with the
space station's retirement plan, the biggest image ever taken of
our galaxy's core, a map of the universe from ten
billion years ago, and Jupiter doing something a bit strange tonight.
Speaker 2: So strap in. This is Astronomy Daily, Season five, episode
fifty nine, and we are not slowing down.
Speaker 1: Let's kick things off with breaking news that literally cannot
wait because it's happening today. NASA's Van Allen probe a
is expected to fall back to Earth tonight.
Speaker 2: Right, This is genuinely happening, as our listeners are tuning in.
The spacecraft, which weighs about six hundred kilogram roughly the
same size as a small car, launched back in August
twenty twelve and has been silently orbiting Earth ever since.
It was switched off in October twenty nineteen, and.
Speaker 1: The US Space Force has been tracking it closely. As
of yesterday afternoon, they were predicting re entry at around
seven forty five in the evening Eastern time, though there's
a plus or minus twenty four hour window on that.
Though it could happen anytime today or tonight now.
Speaker 2: Before anyone panics, the risk to people on the ground
is very low. NASA says the odds of anyone being
harmed are roughly one in four thy two hundred. Most
of the spacecraft will burn up during re entry, and
any surviving fragments are likely to land in the ocean,
which covers about seventy percent of the Earth's surface.
Speaker 1: So this satellite was originally designed for just a two
year mission studying Earth's van Allen radiation belts, those invisible
zones of charged particles trapped by our planet's magnetic field.
But the mission ended up running for nearly seven years
before the probes ran out of fuel.
Speaker 2: And here's the interesting twist. Probe A was actually expected
to stay up in orbit until twenty thirty four. So
what happened. Solar activity the Sun has been unusually energetic
in recent years, and that's caused Earth's upper atmosphere to
expand slightly. More atmosphere means more drag on satellites, and
Probe A got pulled down faster than predicted.
Speaker 1: The Twin Van Allen Probe B is still up there
and isn't expected to come down before twenty thirty, so
we'll be going through this again in a few years.
Speaker 2: The data from these spacecraft is still being used today
helping scientists understand space weather, predict solar storms, and protect
everything from GPS satellites to power grids. A proper little
scientific workhorse.
Speaker 1: And now it's coming home. Keep an eye on the
sky tonight. And while we're in the theme of things
falling from space, let's talk about this incredible story from
Sunday evening. Yes, so, at around ten to seven in
the evening local time on Sunday, the eighth of March
twenty twenty six, thousands of people in Western Europe looked
up and saw an absolutely breath taking fireball lighting up
the sky. We're talking Belgium, France, Germany, Luxembourg, the Netherlands,
all these countries with people outside going what on Earth
is that.
Speaker 2: The fireball lasted? About six seconds, leaving a glowing trail
across the sky. Before breaking apart. People heard multiple loud booms.
That's the sonic boom from the space rock to cintegrating
in the atmosphere. The International Media Organization received over three
thousand reports of sightings and.
Speaker 1: Here's the remarkable bit. Some of it survived. Fragments of
the meteorite, which is what we call it once it
hits the ground, came down in the Rhineland Palatinate region
of western Germany, and one fragment punched straight through the
roof of a house in the city of Koblenz.
Speaker 2: The largest piece left the whole the size of a
football in the roof and landed in an unoccupied bedroom.
Nobody was hurt, thankfully, though the homeowner now has a
very unusual home insurance claim to make.
Speaker 1: Ragman's have already been recovered from the area the Coblins
district of Goals in particular, which will allow researchers to
analyze where this rock came from and what it's made of.
Lisa's Planetary Defense team has been working to estimate the
size of the original object, and they believe it was
just a few meters across.
Speaker 2: What's wonderful about this event is how many cameras captured it.
There's a network called all Sky seven dedicated fireball watching
cameras run by private citizens across Europe that caught it beautifully,
and of course dozens of mobile phone videos went viral
on social media almost immediately.
Speaker 1: Meteorite impacts in populated areas are rare, but not unheard of.
Germany actually had one in two thousand and two near
the Neuschwanstein Castle and another in twenty twenty three in
Schliswick Holstein. But this is one of the most well
documented falls in recent European history. Quite the Sunday evening.
Speaker 2: All right, let's shift from falling things to things we
want to keep up big space policy news this week,
Congress is making moves to extend the life of the
International Space Station.
Speaker 1: The NASA Authorization Act of twenty twenty six passed through
the Senate Commerce, Science, and Transportation Committee last week with
bipartisan support, which is always good to hear, and one
of its biggest changes is pushing back the retirement of
the ISS from twenty thirty to September twenty thirty two.
Speaker 2: So the ISS has been continuously occupied since November two thousand.
That's over twenty five years of humans living in space.
It was originally set to be decommissioned and deliberately de
orbited in twenty thirty. The plan was to crash it
into a remote part of the Pacific Ocean in a
controlled re entry.
Speaker 1: But Congress is saying not so fast. The concern is
that commercial space stations, which are supposed to replace the
ISS in low Earth orbit just aren't going to be
ready in time. Companies like Blue Origin, BAST and Axiom
Space are all working on successor stations, but timelines have slipped,
and there's also.
Speaker 2: A geopolitical dimension to this. China's Tiandong Space Station is
fully operational and will keep running well into the twenty thirties.
The bill specifically uses the language of avoiding a gap
in continuous human presence in Low Earth orbit and explicitly
mentions not wanting to see leadership to China.
Speaker 1: The bill also does something very significant on the funding side.
It rejects proposed cuts to NASA's budget and instead allocates
substantial funding for fiscal year twenty twenty six and twenty
twenty seven. Programs like the Chandra X ray Observatory are
saved under this bill.
Speaker 2: There is a caveat here though. This bill has passed
committee but still needs a full Senate vote and then
the House of Representatives and then a presidential signature. So
it's not law.
Speaker 1: Yet, but it sends a very clear signal about where
Congress stands on the future of American human spaceflight. The
ISS isn't going anywhere just yet.
Speaker 2: Now let's move from policy to pure science, and this
next one is genuinely jaw dropping.
Speaker 1: Astronomers have just released the largest image ever produced by
the ALMA telescope, and it's a portrait of the heart
of our own Milky Way galaxy.
Speaker 2: ALMA stands for Athagama Large Millimeter Submillimeter Array. It's a
telescope complex and the high altitude desert of Chile, and
it detects radio waves rather than visible light, which means
it can see through all the dust and gas that
hides the galactic center from optical telescopes.
Speaker 1: The new image comes from a survey called ACES, the
ALMA CMZ Exploration Survey, and it maps a region called
the Central Molecular Zone. That's the area surrounding the supermassive
black hole at the heart of our galaxy, Sagittarius, a
star stretching across six hundred and fifty light years.
Speaker 2: To put that in perspective, the finished mosaic spans an
area equivalent to three full moons placed side by side
in the sky. It was assembled from hundreds of individual observations,
stitched together like a giant jigsaw puzzle.
Speaker 1: And what it reveals is extraordinary. The central molecular zone
is filled with this intricate web of filaments, long thin
threads of cold molecular gas snaking through the region, feeding
into dense clumps where new stars are being born. It
looks almost like a web or a circulatory system.
Speaker 2: The survey also mapped the chemistry of the region in
incredible detail, detecting dozens of molecules, from relatively simple cons
like silicon monoxide, all the way to complex organic molecules
like methanol, actone, and even ethanol. There's a cocktail of
chemistry going on near the center of our galaxy.
Speaker 1: The team involved was enormous, over one hundred and sixty
scientists from more than seventy institutions around the world, and
they say this is just the beginning an upcoming upgrade
to ALMAH, plus the eventual arrival of ESO's extremely large
telescope will let them push even deeper into this region.
Speaker 2: One researcher put it beautifully, it's a place of extremes,
invisible to our eyes, but now revealed an extraordinary detail.
We'll have a link to the image in the show notes.
It really is something.
Speaker 1: To look at, from the heart of our galaxy to
the dawn of time. Our next story is about a
brand new map of the early universe.
Speaker 2: Researchers have published the largest and most detailed three D
map yet of light from the the universe's early history,
specifically the period between nine and eleven billion years ago.
That's the time astronomers call cosmic noon, when the universe
was producing stars at the fastest rate in its entire history.
Speaker 1: The map was created using data from the Hobby Eberly
Telescope Dark Energy Experiment pet DECKS, which operates from McDonald
Observatory in Texas, and the technique used is really clever.
Speaker 2: Most cosmic maps focus on individual bright galaxies. They are
essentially dot to dot maps of the universe, but this
team used a technique called line intensity mapping, which instead
of counting individual galaxies tracks a specific kind of light
called Lyman alpha radiation.
Speaker 1: Liman alpha light is produced when hydrogen atoms, the most
abundant element in the universe, get energized by young hot stars.
Though wherever you see that glow, you know there's hydrogen
gas and likely star formation happening near by.
Speaker 2: And by tracking that glow across the sky and through time,
the researchers were able to build a three D picture
of not just the bright galaxies, but all the dim,
faint matter in between them, the cosmic web of gas
that connects galaxies together. They called it a sea of light.
Speaker 1: The data set they used was enormous, over six hundred
million spectra collected by headdecks, and here is the staggering part.
The team only used about five percent of those spectra
for their primary research mission. Is this the first time
anyone has gone back and mined that remaining data to
do this kind of mapping.
Speaker 2: What the map Lets scientists do is test their computer
simulations of the early universe against reality. As one researcher
put it, we have simulations of this period, but those
are just simulations, not the real universe. Now we have
a foundation to check if the physics underpinning those simulations
is correct.
Speaker 1: It's like having a map of the world for the
first time. You can finally compare what you thought was
there with what's actually there.
Speaker 2: And finally something you can go outside and see for yourself. Tonight, Jupiter,
the biggest planet in our Solar system, appears to be
doing something a bit odd in the sky.
Speaker 1: If you've been keeping an eye on Jupiter over the
past few weeks, you may have noticed it's slowly moving
across the stars from night to night, which is normal
for planets as they drift against the background of distant
stars due to their orbital motion.
Speaker 2: But tonight and over the coming nights, Jupiter appears to
change direction. This is what astronomers call retrograde motion, and
it's been confusing, delighting, and in ancient times, mystifying people
for thousands of years.
Speaker 1: So what's actually happening. Nothing is actually going backwards. It's
all about perspective. Earth and Jupiter are both orbiting the Sun,
but Earth's orbit is smaller and faster. As Earth catches
up to and begins to pass Jupiter on the inside track,
Jupiter appears to drift backwards against a star background, like
how a slower car on the motorway seems to move
backwards when you overtake it.
Speaker 2: The change is subtle and it happens gradually over many nights,
so don't expect to see it in real time. But
if you compare Jupiter's position tonight to where it was
a few weeks ago, and then check again in a
few weeks, you'll see it. Jupiter is high in the
evening sky right now and easy to find as one
of the brightest objects up.
Speaker 1: There, and tonight there's also a lovely waning gibbous moon
in the southern sky, sitting close to the bright reddish
star and Terry's, so there's plenty to look at if
you step outside after dark.
Speaker 2: No telescope needed for Jupiter, though one will reveal its
four brightest moons, the Galilean moons, which Galileo himself spotted
back in sixteen ten. A pair of binoculars is perfect,
so go look up. And that is it for today's
episode of Astronomy Daily. What a day lights, falling, meteorites,
crashing space stations, getting a reprieve, galaxy portraits, cosmic maps,
and a planet doing loops. The universe never disappoints.
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Speaker 2: We'll be back tomorrow with more from the Cosmos. Until then,
keep looking up clear skies everyone. Sunday Stars
Speaker 1: Start