Anna: Picture Mars a small rusty
coin hanging in the dark. Now watch it
swell over a month until it fills your
window and then shrink away behind you as
you slingshot off toward a world made of
metal.
Avery: That's not a movie trailer, that's a real
time lapse. A NASA spacecraft just sent
home and it's where we're starting today.
Anna: You're listening to Astronomy Daily. I'm
Anna.
Avery: And I'm avery. It's Tuesday 21st
July, 2026, and this is your
daily tour of the universe.
Anna: On the show today, a metal asteroid probe
phones home from Mars. Europe's next great
planet hunter passes its final exam. And a
shoebox sized satellite that could buy us
hours of warning before the next solar storm.
Avery: Plus, how the sun's quiet spell might
forecast its next tantrum. The first
pieces of a radio telescope that'll dwarf the
one from the film Contact. And the meteor
shower that for once is ours to keep down
here in the south.
Anna: Lots to get through. Let's go.
So let's start with that time lapse. NASA's
Psyche spacecraft is on a long, patient
road trip. It launched back in 2023 and
it's heading for one of the strangest
destinations in the solar system. A metal
rich asteroid called 16 Psyche. It
won't arrive until 2029.
Avery: Um, and to get there, it needed a shove back.
On 15 May, it swung past Mars
for a gravity assist, using the planet's
gravity like a slingshot to bend its path and
pick up speed.
Anna: Right, but here's the lovely part. The news
this week isn't the flyby itself. It's what
came home afterwards. Over the last few
weeks, the team has been downlinking and
crunching the data and they've just released
it along with a genuinely mesmerizing month.
Long time lapse of Mars growing and then
receding.
Avery: Why bother running the instruments during a
flyby, though? Mars has been studied to
death.
Anna: Two reasons. First, it's a dress rehearsal.
Ours was a stand in for the asteroid. A
chance to put Psyche science instruments
through their paces under real deep space
conditions before the main event. And second,
after two and a half years in space, you
want to know your gear still works.
Avery: So how did it do?
Anna: Really well. The star of the show was the
Gamma Ray and Neutron Spectrometer. That's
the instrument built with Johns Hopkins
Applied Physics Laboratory with a gamma ray
sensor from Lawrence Livermore. As they came
in close to Mars, the neutron spectrometer
picked up exactly the kind of signal boost
they were hoping
Avery: for the teen science lead David Lawrence
put it nicely. He said around closest
approach, the detector caught a count rate
bump and that it was, quote, very gratifying
to see.
Anna: They were actually too far out about
4,600km to catch
Gamma rays coming off Mars itself. But that
was fine. The point was to prove the
instrument performs. And it did. The
magnetometer and the imager delivered too.
Avery: And all this matters because of what Psyche
16 actually is exactly.
Anna: Most asteroids are rock or ice.
Psyche looks like it might be mostly metal,
iron, nickel and a, uh, scattering of other
elements. The leading idea is that it's the
exposed core of a baby planet.
Planetesimal that got stripped of its outer
rocky layers in the chaos of the early solar
system.
Avery: Which means it's the closest we may ever get
to standing on a planetary core.
Anna: We can't drill down to Earth's core. The
pressure and heat make that impossible. But
we might be able to visit one that's sitting
out in the open. That gamma ray and neutron
spectrometer is the tool that'll read its
chemistry when we arrive. Iron,
nickel, silicon, sulfur,
and tell us what a planetary core is really
made of.
Avery: So the Mars flyby was the warmup and the band
is tuned. 2029 suddenly feels
closer.
Anna: It does. And if you get a chance, do look up
that time lapse. It's a beautiful reminder
that even a routine gravity assist can be
pure poetry.
Avery: From a mission on its way out, uh, to one
getting ready to leave, Europe's next great
planet hunter, ESA's Plato has
just passed its last big test before launch.
Anna: Plato remind everyone what it's built to do.
Avery: It's a, uh, planet detective with 26
cameras working together. And its mission is
a specific to find Earth. Like
rocky planets orbiting in the habitable zone
of sun like stars. Not just any planets.
Worlds where you could plausibly imagine
liquid water on the surface.
Anna: 26 cameras is a lot of eyes.
What was the test?
Avery: It's called electromagnetic compatibility
testing. Engineers sealed the whole
spacecraft inside a chamber at ESA's
technical center in the Netherlands, a room
called the Maxwell chamber, which is
essentially a 9 meter tall Faraday cage
lined with foam spikes to soak up every stray
radio signal. It mimics the electromagnetic
silence of deep space.
Then they switched everything on at once.
All 26 cameras, all the subsystems
humming together to make sure none of them
interfere with each other or with the radios.
No cross talk, no chatter, no one
instrument drowning out another.
Anna: Because up in orbit, if your own electronics
are shouting over each other, you've got a
very expensive problem you can't fix.
Avery: Precisely. And Plato passed. This was the
last major qualification hurdle. Earlier this
year, it survived the violent shaking and
noise of launch simulations and the long
stint in a giant vacuum chamber to prove it
can take the cold and the emptiness of space.
Anna: So what's next for it?
Avery: It's on track to fly on an Ariane 6 rocket.
The current target is 2027. Heading out
to the Sun, Earth, L2 point, that
gravitational parking spot about 1.5 million
kilometers beyond Earth, where the James Webb
Telescope also lives.
Anna: And once it's there, it'll stare at hundreds
of thousands of stars, waiting for the tiny
regular dips that betray a planet crossing in
front.
Avery: That's a dream. If Plato finds a genuine
Earth twin around the genuine sun twin,
that's a headline we'll all remember. For
now, the electronics are ready and the ride
is booked.
Anna: Now, a lot of this week's science is pouring
out of one place. The Royal Astronomical
Society's National Astronomy meeting, which
kicked off in Birmingham yesterday and runs
all week. And one of the first results is a
little satellite with a big job.
Avery: This is the space weather. One which feels
timely given how much we talked about solar
storms on Saturday.
Anna: It does. But this is the other side of that
coin. On Saturday, we talked about how bad
a big solar storm could get. This is about
how much warning we'd have when one's coming.
And right now, the honest answer is not
much.
Avery: How much are we talking?
Anna: For the fastest storms, the really dangerous
coronal mass ejections, we get roughly
15 minutes. That's because our early
warning satellites sit at a point called
L1, about 1.5 million
km sunward of Earth. It passes
them, they call ahead, and 15 minutes later
it hits us.
Avery: 15 minutes to protect satellites and power
grids is not a lot.
Anna: It's barely enough to send an email. So
here's the idea presented at the meeting.
It's a mission called Hanon. It's a
cubesat think shoebox sized, but it
would fly out to about 15 million
kilometers upstream of Earth, 10
times farther than L1.
Avery: Ten times farther out means you see the storm
10 times sooner.
Anna: That's the whole pitch. It could stretch our
warning from around 15 minutes to two or
three hours. And it carries a UK built
magnetometer called Magic, developed at
Imperial College London to measure the
magnetic field carried in the solar wind
alongside instruments from teams in the Czech
Republic and Finland.
Avery: Hours instead of minutes. That changes what
grid operators and satellite controllers can
actually do. Power down safe
mode Reposition.
Anna: Exactly. And Henon is a proving ground,
a technology demonstrator that paves the way
for a bigger permanent European early warning
mission down the line. It's a small box
aiming to give the whole planet a head start.
Avery: Staying with the sun and staying at the
national astronomy meeting. Here's a clever
piece of detective work. It's about
predicting how fierce the next Sun's active
period will be by studying how it goes quiet.
Anna: This is the solar cycle, the roughly 11 year
rhythm where the sun ramps up to a stormy
maximum, then winds down to a sleepy
minimum.
Avery: Right. And forecasting the strength of the
next maximum. How many sunspots, how many
storms has always been notoriously hard.
But a researcher presenting at the meeting
has found a promising clue hiding in the wind
down phase.
Anna: So the secret to the next cycle is written
into how the current one switches off.
Avery: That's the argument. She looked at the Sun's
declining phase and found the precursor, a
signature that seems to foreshadow the size
of the next maximum. And along the way,
there was a neat bit of physics about what
kind of storms we get as the sun quietens
down.
Anna: Go on.
Avery: After the sun switches off from its active
phase, the storms we still get become less
extreme and they start marching to a 27
day beat.
Anna: 27 days. That's roughly one rotation
of the Sun.
Avery: Exactly. And that rhythm is the fingerprint
of a different kind of space weather. Instead
of explosive coronal mass ejections firing
off at random, these calmer storms are driven
by long lived streams of fast solar wind
that sweep past us once per rotation, like
a Lycos beam coming around.
Anna: So it's not just a forecasting trick. It
tells you which mechanism is doing the
driving at different points in the cycle.
Avery: That's what makes it useful. If you can read
the declining phase properly, you get a
running start on predicting the next maximum
and better. Long range space weather
forecasting helps everyone from airlines to
satellite operators.
Anna: Two sun stories in a row. But I love that
they're opposite ends of the same problem.
One's the warning system, one's the long
range forecast.
Let's change the scenery completely from the
sun to some Ceres hardware. Back on the
ground in the United States, three big
players are teaming up to start building the
future of radio astronomy.
Avery: The National Science foundation, the National
Radio Astronomy Observatory,
and this is the interesting1, the U.S.
naval Observatory.
Anna: That last one raises an eyebrow. What's the
Navy doing in radio astronomy?
Avery: Well, more than you'd think. We'll come back
to that. The Headline is they're funding a
Pathfinder, a first installment of something
called the next generation Very Large Array,
the ngvla.
Anna: And listeners will know the original Very
Large Array, even if they don't know the
name. That field of huge white dishes in the
New Mexico desert. It's the telescope from
the film Contact with Jody Foster sitting on
the bonnet of her car, headphones on,
listening to the sky.
Avery: The very one. It's been working for over
45 years. The NG VLA is
its heir. And it's enormous by comparison.
The full vision is 266
antennas with the core in New Mexico. But
this is spread right across the American
Southwest and beyond, roughly 10
times m more sensitive than today's array.
Anna: So what does this pathfinder actually do?
Avery: It focuses on a technique called very Long
Baseline interferometry.
The idea is you link antennas that are
enormously far apart and combine their
signals so together they act like one
telescope, as wide as the whole continent.
That gives you staggeringly sharp images.
Anna: And that's where the Navy comes in.
Avery: That's where the Navy comes in. Those ultra
precise measurements also underpin the
celestial reference frame, the master grid of
fixed points in the sky that we use to know
exactly where we are and which way we're
pointing. It's astronomy and navigation
hand in hand.
Anna: So one instrument helps map black holes
and helps keep the world's clocks and
coordinates honest.
Avery: Beautifully put. Construction and early
operations are expected before the end of the
decade. It's the quiet, unglamorous
groundwork that great discoveries are built
on.
Anna: And that brings us to Skywatch. And
tonight, finally, the southern sky gets the
good seats.
Avery: This is our shower, isn't it? The southern
Delta Aquariids.
Anna: It really is. So many of the famous
meteor showers favor the northern hemisphere,
but the Delta Aquariids are the exception.
Their radiant, the point they appear to
stream from, sits near a star called Skat in
Aquarius. And from Sydney or across New
Zealand, that's high overhead. We get the
front row view.
Avery: When do they peak?
Anna: Officially around the 29th and 30th of
July. But and this is the important
bit, there's a catch. This year the peak
lands right on a near full buck moon.
And that much moonlight will wash out these
meteors because they tend to be faint.
Avery: So the peak date, uh, is actually the wrong
night to go out for once.
Anna: Yes, the smart move is to go out this week
instead. Right now, the moon is still waxing
and sets before dawn, which leaves the sky
nice and dark in those early morning hours.
And this shower is generous. It rambles along
for days rather than spiking on one night.
So the moon free mornings this week are your
best window.
Avery: What are we actually looking for?
Anna: Under a proper dark sky, maybe 15
to 20 meters an hour. They're on the faint
side, long and graceful rather than
flashy. And a nice fraction of them leave a
glowing trail that lingers for a second or
two after they've gone. The suspected parent,
by the way, is a comet called
96PMachholz.
Avery: Any tips for getting the most out of it?
Anna: Get away from town lights if you can wrap up
warm. It is winter down here. And give your
eyes a good half hour to adapt. Buy
back, take in as much sky as you can rather
than staring at one spot. And be patient.
And a bonus, toward the very end of the
month, a second shower. The Alpha
Capricornids joins in with slow, bright
fireballs. So keep watching into early
August, faint
Avery: and graceful with the odd fireball for drama.
That's a lovely winter's night under the
stars.
Anna: It is.
Rug up. Look up.
Avery: Before we go, a quick one to chew on. We
mentioned Psyche is heading for a metal
asteroid. Here's the teaser. If you could
somehow bring that metal to market. Its value
has been estimated at a number so large
it's essentially meaningless. More than the
entire world economy. We'll leave the exact
figure for the trivia cards.
Anna: A quintillion dollar rock. File that one
away.
Avery: So today, Psyche sent home its Mars
flyby data. And the gorgeous time lapse
Plato passed its final test on the road to
launch. A shoebox satellite called Hainan
could turn 15 minutes of storm warning into
three hours.
Anna: The sun's quiet spell may help us forecast
its next loud one. The first pieces of the
mighty NGVLA are being funded.
And the Delta Aquarids are lighting up our,
uh, Southern skies this week.
Avery: That's a full show. Everything we covered is
linked in the show notes at astronomydaily
IO and you can find us on all the
socials astrodaily Pod.
Anna: If today taught you something new, share it
with a friend who looks up. I'm Anna.
Avery: And I'm Avery. Thanks for spending part of
your day with us.
Anna: Until tomorrow, clear skies.