Starship V3 Flight 12: A Giant Leap for SpaceX | Neptune's Moon Mystery Unveiled

Anna: The world's biggest rocket is sitting on a

launch pad in South Texas right now. And

tonight, for the first time ever,

Avery: it's going to Fly Starship

version 3 flight 12. And it is

absolutely the biggest story in spaceflight

today.

Anna: We've also got a deep solar system mystery

wrapped up by the James Webb Space Telescope

and some genuinely unsettling news about

what the galaxy may be full of.

Avery: Not very many Earths.

Anna: I'm Anna.

Avery: And I'm, uh, Avery. This is Astronomy Daily.

Today's space news from the universe to you.

Anna: We've been tracking the Starship V3 story for

a couple of days now. The delays, the wet

dress rehearsal, the OSHA investigation.

And today is finally the day. The launch

window opens at 5:30 this afternoon,

Texas time, and SpaceX is going for it.

Avery: This is Flight 12 in the Starship program

overall, but it's the first flight of the V3

design, which is by some measures an almost

entirely new rocket.

Anna: Elon Musk himself said that nearly every

part has been redesigned. Compared to V2,

the rocket now stands

124.4 meters tall.

That's just over 400ft, making it

officially the tallest rocket humanity has

ever built.

Avery: And it's not just bigger for the sake of it.

The big structural change on this version is

that Starship V3 is designed for in orbit

refueling for the first time. That's the

capability that unlocks deep space missions

to the moon and eventually Mars.

Anna: ASA is counting on exactly that.

Starship has been selected as the human

landing system for the Artemis program. The

current plan is for a docking test in low

Earth orbit as early as 2027,

with a moon surface landing targeted for the

Artemis 4 mission in 2028.

Avery: But there's a mountain to climb before any of

that. SpaceX still hasn't sent Starship into

full orbit. The program has seen explosions,

delays, and last week a contractor working at

Starbase in Texas died in a fall.

The US Occupational Safety and Health

Administration has opened an investigation.

Anna: Today's flight profile is suborbital, similar

to recent missions. The plan is to deploy

20 Starlink simulator satellites, attempt

a single Raptor engine relight in space,

and test the heat shield by deliberately

removing one tile to measure

aerodynamic load on neighboring tiles during

re entry.

Avery: That tile experiment is actually quite

clever. You need to understand the failure

modes before you can fix them.

Anna: Weather is sitting around 55%

favorable right now. Not ideal, but

workable. And there is a lot riding on this.

Beyond engineering pride. SpaceX's planned

IPO, which could value the company at, uh, up

to $1.75 trillion,

would be the largest public offering in

history. Today's test flight is very much in

the shop window.

Avery: No pressure, then.

Anna: None whatsoever. We'll have the result in

tomorrow's episode. Whatever happens tonight,

it's a pivotal moment for the program and for

the future of human spaceflight.

Avery: Next up, today. Billions of years ago,

Neptune had a tidy family of moons. Then

a rogue intruder arrived and tore everything

apart. New research published in the journal

Science Advances suggests that one moon

survived the chaos, and we've known about it

since 1949.

Anna: That moon is Nereid, Neptune's third

largest satellite and one of the strangest

orbits in the solar system. It swings as

close as 1.4 million kilometers to

Neptune and as, uh, far away as 9.6.

For comparison, our moon is a pretty

consistent 384,000

kilometers from Earth.

Avery: For decades, astronomers have known that

Nereid's extreme elliptical orbit was

unusual, but they couldn't agree on why. The

leading theory was that it was a captured

object, something that drifted in from the

outer solar system and got gravitationally

trapped. But this new study, led by Matthew

Belyakoff at the California Institute of

Technology, strongly rules that out.

Anna: The team used NASA's James Webb Space

Telescope to study Nereid in detail, and

what they found changes the story

significantly. Their observations are

consistent with Nereid being an original moon

of Neptune, one that formed right alongside

the planet, but was thrown into its wild

orbit when Neptune captured its largest moon,

Triton.

Avery: And Triton's story is quite the tale itself.

Triton is thought to have originated in the

Kuiper Belt, the frigid region beyond Neptune

where objects like Pluto live. At some point,

Triton was captured by Neptune's gravity, and

the gravitational chaos of that event

scattered Neptune's original moons onto

collision courses with each other. Most were

destroyed.

Anna: Neptune's innermost moons are thought to be

the shattered remnants of those originals,

rubble that coalesced after Triton's

arrival. Nereid, according to this new

research, escaped that fate by being thrown

into its current extreme orbit. Far

enough out to survive, but close enough to

still be bound to Neptune.

Avery: As Belyakov puts it, it takes a long time to

do science. This mystery began with Nereid's

discovery in 1949, and we may finally

have some answers in 2026. Thanks to Webb.

The researchers note that this work would

simply not be possible with any previous

telescope. It really is a testament to what

Webb continues to deliver.

Anna: A survivor of 4 billion years of

Cosmic chaos. Not a bad story for a

Thursday.

Avery: Here's a number that should give you pause.

In 2005, the European Space

Agency was tracking around 16,000

pieces of debris in orbit. By

2026, that number has grown to more than

44,000, an increase of roughly

180%. And that's only what we

can track.

Anna: The vast majority of debris is too small

to track at all. ESA estimates there are

millions of fragments out there paint flecks,

bolt fragments, shards from old rocket stages

moving at orbital velocities. Even something

tiny can cause catastrophic damage.

Avery: But new research is drawing attention to a

consequence that gets less coverage than the

collision risk. The scientific cost. A

study looking at NASA's Earth observing

satellites, specifically Aqua, Terra and

Aura, found that since 2005,

this fleet has had to execute avoidance

maneuvers at least 32 times to dodge

debris.

Anna: And those maneuvers aren't free, not in terms

of fuel and possibly not in terms of data.

According to records from the Land Data

Products Evaluations Assessment, some of

those avoidance burns may have corrupted

climate data. During the collection window.

You move the satellite, the instruments point

somewhere different, and the record has a gap

or an artifact.

Avery: These satellites were not designed with this

level of debris in mind. Aqua, for instance,

has lasted 18 years longer than its original

design life. It's been incredibly productive,

but it only has so much fuel left. Every

avoidance maneuver burns some of that

reserve.

Anna: And as one insurance analyst put it to

space.com even without collisions,

space debris has an economic cost. Each

time a satellite has to maneuver to avoid a

potential collision, it uses fuel, which is a

finite and precious resource. The headline

quote from researchers is blunt Things will

get worse before they get better.

Avery: The good news is that two companies have

announced plans to begin active debris

removal from orbit in 2027. The

technology exists. The will and the

regulation need to catch up quickly.

Anna: Next on today's agenda. Over the past year

or so, results from the dark energy

spectroscopic instrument DESI have

been causing excitement and consternation

in equal measure. The data appeared to

hint that dark energy, the mysterious

force driving the accelerating expansion of

the universe, might be evolving over

time, changing in strength as the

cosmos ages.

Avery: Which, if true, would be a genuinely enormous

deal. The standard cosmological model treats

dark energy as a fixed cosmological constant.

If it's changing, the model needs to be

rebuilt from the ground up.

Anna: Exactly. But new research published in

Physical Review D is urging caution.

Scientists at the Tata Institute of

Fundamental Research in Mumbai have found

something a small but simple significant

mismatch between two Key data sets

used to measure dark energy's

supernova brightness data and baryon

acoustic oscillations, which are essentially

ripples in the distribution of galaxies

across the universe.

Avery: And the mismatch matters because the DESI

results that pointed to evolving dark energy

relied on combining those two datasets. If

they aren't mutually consistent, if there's a

small but real discrepancy in what they're

measuring, then the apparent signal of

evolving dark energy could be a systematic

artifact rather than a genuine physical

phenomenon.

Anna: The researchers traced the mismatch back to a

potential violation of what's called the

cosmic distance duality relation,

a fundamental geometric relationship

that underpins how we calculate distances in

the universe. If that relation is being

violated, or if there are subtle calibration

errors in the datasets, then the apparent

evolution of dark energy may simply

disappear.

Avery: What does this mean in practical terms?

Anna: It means we don't know yet. This paper

doesn't prove dark energy is constant. It

just raises a serious methodological

flag. Science is working exactly as

it should. Extraordinary claims get

extraordinary scrutiny. More data from

DECE's third release and from ESA's Euclid

mission should help clarify things later this

year.

Avery: The universe remains stubbornly mysterious,

which is

Anna: honestly what keeps us in a job.

Avery: Now, here's a question that sounds simple but

turns out to be extraordinarily complex.

What's the most efficient way to get from

Earth to the Moon?

Anna: I mean, you point the rocket at

Avery: it, you'd think, right? But no, because in

spaceflight, the most direct path is almost

never the most efficient one. And the new

study, published in the journal

Astrodynamics, has found the trajectory to

the Moon that is better than any route

previously described in the scientific

literature.

Anna: How much better?

Avery: The new route uses 58.8 meters per

second less fuel, what engineers call Delta V

compared to the previous, best known path.

That might sound tiny. But consider the total

fuel budget for an Earth to Moon transfer is

around 3,343 meters per second.

Shave nearly 60 off that, and you've made a

real difference. Every meter per second saved

is, as the researchers put it, a massive

amount of fuel consumption.

Anna: So how did they find it?

Avery: The team from the universities of Colimbra,

Porto and Evora in Portugal and the

University of so Paulo in Brazil used a

mathematical approach called the theory of

functional connections. It dramatically

reduces the computing power needed to

simulate trajectories, which let them test

around 30 million different routes. Previous

studies had managed around 280,000.

Anna: That's an enormous leap in the search

Avery: space, and it paid off. The most efficient

route they found is counterintuitive. Instead

of heading more or less directly toward the

Moon, the spacecraft first swings toward a

point called the L1 Lagrange point, the

gravitational balance point between Earth and

the moon. About 85% of the way there,

it enters a stable orbital pathway around

L1, then departs on an unstable pathway

that transitions it, uh, into lunar orbit.

Anna: Essentially using the Moon's own gravity

as part of the propulsion system.

Avery: Exactly. The team also notes that the L1

point maintains constant line of sight with

Earth, which means communication is

uninterrupted throughout the journey. And

crucially, this method can be adapted. You

could use it for any planet, moon system, or

any orbital transfer problem. As the

researchers say, the systematic analysis they

developed could be adopted much more widely

going forward.

Anna: Small savings Scaled across dozens of

future Artemis missions, that adds up to a

Avery: lot of rocket fuel and a lot of money.

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Anna: All right, on to our next story. And this

one will surprise many. If you've ever

looked up at the night sky and felt reassured

that the galaxy must be full of

Earth's worlds with oceans,

atmospheres and the potential for life,

new research from the European Geosciences

Union conference in Vienna may give you

pause.

Avery: That's not the most comforting preamble.

Anna: Preliminary results presented by Shawn

Jordan, a postdoctoral researcher at ETH

Zurich, suggest that our galaxy may be

filled with a far greater number of Venus

like worlds than true Earth analogs,

and that this might simply be how rocky

planet formation works.

Avery: Walk us through the science.

Anna: When a rocky planet forms, it goes through

what's called a magma ocean phase.

Essentially the entire surface is molten.

As it cools, the atmosphere it develops

heavily depends on its chemistry and its

distance from its star. Dourdan and

colleagues argue that it's actually quite

straightforward to end up with a carbon

dioxide dominated atmosphere, thick,

hot, crushing Venus style. After

that cooling phase, getting to an Earth like

nitrogen oxygen atmosphere is harder,

Avery: meaning a, uh, Venus outcome might be the

path of least resistance.

Anna: That's the implication. And there's a

philosophical reframe buried in here too.

Jordan suggests that Venus may not have gone

wrong. It may simply have been born that way.

A planet that came out of its magma ocean

phase looking exactly like Venus does today

without ever having oceans or a temperate

climate.

Avery: How many exovenus candidates are we actually

talking about?

Anna: At least a few dozen rocky exoplanets are

considered potential Venus analogues, though

none have been confirmed as such. We don't

yet have the atmospheric characterization

tools to be certain. The challenge is that a

Venus like atmosphere, although sulfuric

acid clouds, looks very similar to a, uh,

featureless atmosphere in our current

observations.

Avery: There's a telling phrase in the coverage of

this research that our own Venus has been

described as criminally underexplored.

Only one mission has sent a lander since the

Soviet program in the 80s.

Anna: That's the awkward irony. We're looking for

Venus twins across the galaxy while

barely understanding the one we have next

door. ESA's Envision mission and

NASA's DaVinci program are, uh, both in

development, and they can't come soon enough.

Our nearest twin, the cautionary tale,

deserves a much closer look from a

habitable

Avery: paradise candidate to the galaxy's most

common world. Quite the motion.

Anna: Science rarely flatters our assumptions

before we

Avery: head out, A quick look at the sky for our

Southern Hemisphere listeners, particularly

in Australia and New Zealand, this week

Anna: is a beautiful time to watch the evening sky.

Jupiter is blazing brightly in the west after

sunset, and the waxing moon is sliding past

it over the next couple of nights. Tonight

they're particularly close together, making

for a stunning naked eye pairing.

Avery: No equipment needed, just step outside about

30 to 45 minutes after sunset, look west

and you'll see the moon and the brightest

star near it. That's Jupiter. It's one of

those simple, wonderful reminders that the

solar system is right there every clear

night.

Anna: Cloud free skies to all of you.

Avery: That is Astronomy Daily for Thursday, May

21, 2026. Six stories from the

launch pad in Texas to the farthest reaches

of Neptune's

Anna: battered moon and the starship. Result.

Whatever it is, we'll have it for you

tomorrow.

Avery: If you enjoyed the show, please take a moment

to subscribe and leave a rating. Wherever you

get your podcasts, it genuinely makes a

difference.

Anna: You can find us at astronomydaily

IO and on socials

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bytes.com podcast network.

Avery: Until tomorrow, keep looking up Clear

Skies Astronomy Day

Anna: stories.

In this episode