Speaker 1: Hello, and welcome to Astronomy Daily.
Speaker 2: I'm Anna and I'm Avery. You're listening to Season five,
episode forty two for Wednesday, the eighteenth of February twenty
twenty six, And what a day to be a spaceman.
Speaker 1: Absolutely tonight right now, in fact, the Moon is sliding
so close to mercury that it's actually hiding it from
view for skywatchers in parts of the southern United States.
A genuine celestial magic trick happening as you listen.
Speaker 3: And that's just one of six stories we're bringing you today.
We've got NASA's Artemis two on the verge of a
crucial fueling test, a European rocket making a big move
in the satellite broadband race, a genuinely new twist in
the ongoing saga of our interstellar Visitor, and two stories
that I promise will make you rethink some things you
thought you knew about the Solar System.
Speaker 1: Big show, let's get into it, so Anna.
Speaker 3: Let's start with the biggest space story of the week,
and honestly the one that could define the Artemis two.
Speaker 1: Yes, for anyone who needs a quick refresh, Artemis two
is NASA's first crude mission around the Moon since Apollo
seventeen in nineteen seventy two. Four astronauts Reed Wiseman, Victor Glover,
Christina Cock, and Canada's Jeremy Hansen are preparing to fly
a ten day loop around the Moon and back. No
lunar landing, but a crucial proving flight before we put
boots on the surface.
Speaker 3: And they are so close. The rocket is sitting on
Path thirty nine B at Kennedy Space Center right now.
But before NASA will commit to a launch date, they
need to successfully do what's called a wet dress rehearsal,
a full practice countdown where they actually load the rocket
with fuel and take it right to the edge of launch,
then drain it all out again.
Speaker 1: They did that once already on February third, and it
didn't go smoothly. A liquid hydrogen leak cropped up, the
exact same kind of problem that plagued Artemis one one
three years ago. The countdown was terminated at T minus
five minutes and fifteen seconds, close but not close enough.
Speaker 3: Which pushed the February launch window off the table entirely.
NASA administrator Jared Isaacman was fairly philosophical about it. He
said This is exactly why you do a rehearsal to
find these issues before you're flying with crew. But the
clock is ticking.
Speaker 1: Since then, engineers have replaced two seals and a clogged
filter in the hydrogen fueling system. They ran a partial
confidence test on February twelfth to check the repairs, and
now tomorrow, February nineteenth, they begin tanking day for the
second full wet dress rehearsal.
Speaker 3: This is the one that counts. If the test goes cleanly,
no oud of limits, hydrogen concentrations countdown proceeds all the
way to the terminal phase, NASA will analyze the data
and set a launch date. The current earliest possibility is
March six.
Speaker 1: It's worth noting just how historic mission is beyond the
Moon return angle, Victor Glover will become the first person
of color to travel beyond low Earth orbit. Christina Cock
will be the first woman, Jeremy Hansen will be the
first non American. Every single person on that crew is
making history in their own right.
Speaker 3: So tomorrow is genuinely a day to watch. We'll be
keeping a close eye on how the tanking goes, and
we'll have updates as they come through.
Speaker 1: All right. Let's bring it back to Earth, or rather
to the sky above Earth, because tonight is one of
those rare evenings where if you happen to be in
the right place and you look up at the right moment,
you'll see something genuinely extraordinary.
Speaker 3: Two things actually, First, the moon and mercury. Tonight, February eighteenth,
a slender, one and a half day old crescent moon
is passing extremely close to Mercury in the western sky
just after sunset, and I mean extremely close.
Speaker 1: For observers along a narrow band of southern US states.
We're talking Arizona and New Mexico, Texas, Louisiana, Mississippi, and Georgia,
the moon will actually pass directly in front of Mercury
and block it from view entirely. That's called an occultation.
Mercury literally disappears behind the moon's dark limb and reappears
on the other side.
Speaker 3: For everyone else across North America and beyond, it won't
be a full occultation, but you'll still see a dramatically
close pairing. East Coast observers will see Mercury sitting just
north of the moon as twilight falls. By the time
darkness reaches the west coast, the Moon will have shifted
to within about one degree of the planet. Venus hangs
brilliantly below them as a helpful reference point.
Speaker 1: Now the window is tight. Mercury sets not long after
the sun, so you want to get outside as soon
as the sky darkens. Look low in the west southwest
if you can spot Venus, and you'll have no trouble
doing that. It's blazingly bright. Mercury will be nearby. The
moon makes it easy tonight.
Speaker 3: And if that warn enough, Jupiter watchers have a tree
two tonight. Ganymede, Jupiter's largest moon and the biggest moon
in the entire Solar System, is transitting across Jupiter's face.
East coast observers can see it underway as soon as
it gets dark. It takes just over three hours to
cross the disk, and then Ganymede's shadow follows it across,
creating that striking black dot effect on Jupiter's cloud tops.
Speaker 1: So tonight really is a two for one skywatching event.
Mercury and the Moon in the west at dusk, Jupiter
and Ganymede in the southeast through the night. If you
have binoculars or a small telescope. Even better, get outside,
staying with today's news, and this one happened literally today.
Europe's Arion six rocket has successfully launched thirty two satellites
into orbit for Amazon's Project Kuiper.
Speaker 3: For those not familiar with Kuyper, Amazon has been quietly
building a large constellation of broadband Internet satellites designed to
take on space exist. This is a big commercial play.
Darlink currently leads the market with thousands of operational satellites,
but Amazon has the resources and ambition to make this
a genuine competition.
Speaker 1: What's notable about today's launch is that it used the
most powerful configuration of Airon six, flying with four strap
on boosters rather than two. It was essentially a statement
of capability from the European side of the commercial launch industry.
This rocket can handle serious payloads.
Speaker 3: There's also a bigger picture here. Arion six has had
somewhat of a turbulent road. It came in behind schedule
and face some early technical hurdles, but launches like this,
winning commercial contracts for a high profile constellation like hyper
are exactly what Europe needs to keep its launch industry
competitive in an era dominated by SpaceX and an increasingly
capable Chinese launch sector.
Speaker 1: The broadband satellite race is one of the defining infrastructure
stories of this decade. I'd argue Starlink has already changed
what connectivity looks like in remote areas and conflict zones,
hyper Amazon's one Web investments, the Chinese Go Wong constellation.
They all point to a future where low Earth orbit
becomes genuinely critical economic territory.
Speaker 3: Today's launch is one tile in that much larger mosaic
thirty two satellites closer to that future.
Speaker 1: Now an update on our Interstellar Visitor, and I do
mean update. There is genuinely new information here happening right now.
Speaker 3: I know we've given three i at Lists quite a
run over recent episodes, but this one earns its place today.
Speaker 1: Completely for new listeners. Three i at Lists is only
the third interstellar object ever confirmed to pass through our
Solar System. It arrived from outside our stellar neighborhood, swung
around the Sun last October, and is now heading back
out into the galaxy forever. We will never see this
object again.
Speaker 3: Here's what's happening right now. Issa's Juice spacecraft. That's the
Jupiter icy Moons Explore currently en route to Jupiter pass
with an observational range of three I atlas back in
November last year. Due to the challenging thermal conditions during
Juice's transit through the Inner Solar System, the data collected
couldn't be downlinked straight away. That data is now being
transmitted to Earth. The window is February eighteenth to the
twentieth today.
Speaker 1: If successful, these would be the closest ever observations of
an interstellar object by a spacecraft. Now, Juice didn't do
a dedicated flyby, its trajectory is locked in for Jupiter,
but even opportunistic observations from its suite of cameras, spectrometers,
and particle detectors could give us a perspective on three
I at lists that no Earth based telescope can provide.
Speaker 3: And the data would complement an extraordinary recent run of discoveries.
Hubble has directly imaged the nucleus for the first time.
JWST detected methane in its atmosphere, a molecule never before
seen in an interstellar object, and the object is still
spinning faster than it was before its solar encounter, a
legacy of all that outgassing as it's swung close to
the Sun.
Speaker 1: Three I atlass is now about three and a half
astronomical units from the Sun in the constellation Gemini. It's fading,
but still reachable with a decent amateur telescope, and it
has one more big act to play, a close pass
by Jupiter in March, which may trigger fresh outbursts as
Jupiter's tidal forces stress the nucleus.
Speaker 4: An extraordinary object, and the fact that we have a
spacecraft data downlink happening as we record today makes it
entirely current. What report would Juce found as soon as
the science teams release their analysis.
Speaker 1: Right deep time now. I genuinely love this next story
because it takes something you thought you understood Saturn's rings
and reframes the entire origin of the system.
Speaker 3: New research by mattia Chuk at the SETI Intitude, about
to be published in the Planetary Science Journal, proposes a
dramatic two stage catastrophe that reshaped the entire Saturturnian system
roughly four hundred million years ago, and I mean reshaped everything. Titan,
the rings, Iapetus, Hyperion, all of it connected to one
ancient collision.
Speaker 1: Let's set the scene. Saturn has puzzled planetary scientists for
a long time. Its axial tilt is an unusually steep
twenty six point seven degrees. You don't expect gas giants
to form that way. Titan is migrating away from Saturn
at a surprisingly rapid rate. The moon Iapetus sits at
an oddly inclined orbit, and the rings are far younger
than the planet itself, only a few hundred million years old.
Geologically speaking, one thing after another that didn't quite add up.
Speaker 3: Juke and colleagues ran simulations and found the scenario that
explains it all at once. The key player is a
moon they're calling Proto Hyperion. Saturn used to have this
additional mid sized satellite orbiting in the Outer System. When
saturn Spin orbit resonance with the other planets in the
Solar System broke down, Proto Hyperion was destabilized, it drifted inward,
and it collided with a Proto Titan.
Speaker 1: The merger of those two moons roughly four hundred million
years ago set off a chain reaction. Some of the
collision debris accreted around what would become today's Titan, explaining
why Titan's surface looks surprisingly young despite the moon itself,
being ancient, Titan absorbed new material and essentially reset its surface.
Speaker 3: Other debris from the collision perturbed the inner moon system.
Titan's resonant gravitational interaction with Protodone and Proto Rhea caused
further instabilities, more collisions, more debris. Most of that material
eventually reaccreted into the inner moons we see today mimis Enceladus.
Test this Dione Rhea, but a fraction of it stayed dispersed.
That fraction became Saturn's.
Speaker 1: Rings and Hyperion, the small, oddly shaped, walnut like moon
that looks like it survived a very bad day. According
to the model, it actually did survive a very bad day.
It formed from the debris of that Proto Hyperion and
Prototitan collision and was captured into resonance with Titan. The
researchers note that in most of their simulations, Hyperion was
lost entirely. Its survival in a relatively small number of
runs suggests the real system was genuinely close to being
quite different.
Speaker 3: What I find compelling about this is how elegantly one
event connects everything. The tilt of the whole planet, the
age of the rings, the orbits of Iapetus and Hyperion.
Titan's migration rate one ancient merger explains it all.
Speaker 1: Now, the researchers are careful to say this is a hypothesis,
not a confirmed history. Simulations can be suggestive without being definitive.
But NASA's Dragonfly mission is heading to Titan. It launches
in twenty twenty eight and arrives in twenty thirty four.
One of the things Dragonfly will investigate is the age
and history of Titan's surface. If the surface shows evidence
of that ancient resetting, that would be a powerful confirmation.
Speaker 3: Four hundred million years of cosmic history hiding in a
walnut shaped moon. I love the stuff.
Speaker 1: And finally a story that will make you rethink just
how long it takes to get to Mars, or at
least how long it might take one day.
Speaker 3: Russia State Nuclear Corporation rose Adam, through its Troyice Institute
near Moscow, has been developing a nuclear powered magna plasma engine,
and they're making a bold claim that this technology could
get a crude spacecraft to Mars in thirty days.
Speaker 1: To put that in context, a can ventional chemical rocket
takes roughly eight months to reach Mars thirty days would
be a transformation, not just an improvement. It would fundamentally
change the feasibility of human Mars missions. Less radiation exposure
for the crew, less time, and microgravity, a completely different
logistical calculus for resupply and emergency scenarios.
Speaker 3: The engine works by accelerating hydrogen using electromagnetic fields rather
than combustion, to a velocity of one hundred kilometers per second.
That's roughly twenty two times faster than the exhaust velocity
of a conventional chemical rocket. The working body is plasma
charged particles, and it's driven by an onboard nuclear reactor
that provides the sustained electrical power the accelerator needs.
Speaker 1: Importantly, this isn't a launch engine. You'd still use conventional
chemical rockets to get off Earth surface and into orbit.
The plasma system switches on once you're in se for
the interplanetary cruise, smooth continuous acceleration followed by a long
deceleration burn.
Speaker 3: The prototype is currently running ground trials inside a fourteen
meters vacuum chamber designed to replicate deep space conditions. The
researchers say the engine has demonstrated sufficient longevity over twenty
four hundred hours for a Mars transportation operation. A flight
ready prototype is targeted for twenty thirty.
Speaker 1: Now, and this is important. There are real caveats here.
No peer reviewed data has been published yet. The thrust
is very low, around six newtons. Integrating a nuclear reactor
into a crude spacecraft is an enormous engineering challenge in itself,
with regulatory, thermal and radiation shielding hurdles that remain largely
unsolved publicly.
Speaker 3: Fare points, but the broader context is genuinely interesting. NASA
is investing in its own plasma propulsion programs. The Vasi
mer engine from ad Astra Rocket Company in Texas targets
a Mars trip of forty five to sixty days. China
has plasma thrust or research under way.
Speaker 4: Two.
Speaker 3: There's a real multi nation push to solve the propulsion
problem for deep space travel.
Speaker 1: Chemical rockets got us to the Moon. Getting to Mars regularly,
safely and at human timescales requires something different. This is
where that search is heading, wherever it ultimately leads.
Speaker 3: Thirty days to Mars, even as an aspiration. That's a
sentence worth sitting with.
Speaker 1: And that's our six stories for Season five, Episode forty two.
What a lineup from a rocket on a launch pad
in Florida to a crescent moon swallowing Mercury to the
debris of a four hundred million year old collision still
orbiting Saturn, and.
Speaker 3: An interstellar comment sending us its last data from the
edge of the Solar System while Russia dreams of getting
to Mars in a month. Base never has a quiet week.
Speaker 1: If tonight's sky events caught your attention, there is still
time to get outside Mercury and the Moon in the west,
Jupiter and Ganymede in the southeast. You have your orders
and keep.
Speaker 3: An eye on Artemis. Tomorrow's fueling test is one of
those days where the news could come fast. We'll be
on it.
Speaker 1: Thank you so much for spending part of your Wednesday
with us. We'll be back tomorrow for more from the universe.
Speaker 3: Until then, clear sky is everyone, Sunny day
Speaker 4: Star is, Star is