SpaceX's Ninth Starship Flight, A Hidden Dwarf Planet, and Europa's Future Habitable Zone

Anna: Hello and welcome to Astronomy Daily. I'm

your host, Anna, bringing you the latest and

most fascinating developments from across the

cosmos. Today we've got a great lineup of

stories that showcase both human ingenuity

and the wonders of our universe. We'll

dive into SpaceX's ninth Starship test

flight, a mission with impressive successes,

but also some dramatic setbacks along the

way. Then we'll explore a significant new

discovery in our own solar system. A a dwarf

planet that's been hiding in plain sight for

years and represents the largest such find in

over a decade. We'll also journey to

Europa and examine its potential future

habitability, peek at a bizarre star within a

star system and investigate new research

suggesting habitable moons might be more

common than we thought. So get comfortable

and join me for a journey through the latest

astronomical discoveries that continue to

expand our understanding of the universe we

call home.

First up today, SpaceX's Starship

Super Rocket completed its ninth flight test

recently and it was quite the rollercoaster

of achievements and challenges. The launch

began impressively at SpaceX's starbase in

Texas, with the massive 400 foot tall

rocket lifting off as planned. The first

stage booster, known as Super Heavy,

performed Beautifully with all 33 methane

fueled engines firing perfectly, generating

an astonishing 16.7 million pounds

of thrust, more than twice the power of the

Saturn 5 rockets from the Apollo era.

What made this launch particularly notable

was that this marked the first time SpaceX

reused a Super heavy booster, as this

same first stage had previously flown during

January's seventh test flight. The successful

reuse represents a significant milestone in

SpaceX's quest for rapid reusability of its

rocket components. However, the mission

encountered several significant challenges.

Once the second stage, known as ship,

separated from the booster, the planned

deployment of eight Starlink satellite

simulators had to be scrubbed when SHIP

couldn't open its payload doors. This would

have been Starship's first ever payload

deployment, making the failure particularly

disappointing. Things went from bad to worse

as SHIP continued its journey. As it headed

toward a scheduled splashdown in the Indian

Ocean, it began spinning uncontrollably.

SpaceX commentators reported that the second

stage had lost attitude control, apparently

due to propellant leaks. The spacecraft

ultimately broke up during its uncontrolled

descent over a cleared area of ocean. Despite

these setbacks, the test flight wasn't

without its successes. The super heavy

booster executed several challenging

manoeuvres after stage separation, including

a directional flip over and maintaining a

heightened angle of attack. Both techniques

aimed at improving fuel efficiency for future

missions. The booster also demonstrated its

ability to maintain controlled descent even

when simulating a single engine failure.

SpaceX CEO Elon Musk remained

characteristically optimistic, noting on

social media that Starship made it to the

scheduled engine cutoff point, which

represented a significant improvement over

previous flights. He also highlighted that

there was no significant loss of heat shield

tiles during ascent, another important

achievement. Looking ahead, Musk

indicated that SpaceX plans to accelerate its

launch cadence for the next three Starship

flights, aiming for approximately one launch

every three to four weeks. This aggressive

schedule reflects SpaceX's determination to

rapidly iterate and improve the Starship

system. This persistence is crucial

given Starship's central role in NASA's

Artemis programme, where a version of the

spacecraft is slated to serve as the landing

system for the Artemis 3 mission, which would

mark humanity's return to the lunar surface.

Beyond moon missions, SpaceX has even

more ambitious plans, with Musk suggesting

that starship flights to Mars could begin as

early as 2024. While that timeline

seems extraordinarily ambitious, the

company's approach of testing, failing,

learning, and rapidly improving continues to

push the boundaries of what's possible in

space exploration.

Now let's turn our attention to discovery. In

exciting news for planetary scientists, a

newly discovered object in the outer solar

system has been confirmed as a dwarf planet,

the largest such discovery in more than a

decade. Currently bearing the

preliminary designation 2017 of

201, this celestial body measures

approximately 700 kilometres, about 400

miles across, and follows an extremely

elliptical orbit around our sun.

What makes this orbit particularly remarkable

is its lengthy duration, taking an

estimated 25,000 years to complete a single

circuit around the sun. This places

2017 of 201 in the

exclusive category of dwarf planets,

alongside more familiar objects like Pluto,

the asteroid Ceres, and a handful of other

similar bodies in the outer solar system.

The discovery story is almost as fascinating

as the object itself is. The dwarf planet was

hiding in plain sight, buried within

terabytes of publicly available astronomical

data, some of which was collected more than a

decade ago. Finding this celestial needle in

a haystack required months of computational

work to distinguish it from the countless

background stars and noise. The

detection came through painstaking analysis

of data originally collected for the Dark

Energy Survey, or ds. While

that project primarily focuses on studying

gravitational lensing in distant galaxies,

the survey's ability to detect extremely

faint objects made it inadvertently perfect

for hunting distant solar system objects.

Sihao Cheng from the Institute for Advanced

Study led the discovery team, noting that

while in principle anyone could have made

this discovery using the public data, the

process was extraordinarily demanding.

Developing the algorithm alone took several

months, followed by additional months of

computation. And as they scanned through

roughly 200 terabytes of data using hundreds

of processors, what made the search

particularly challenging was the widely

separated observation dates. Unlike

targeted asteroid searches that typically

take successive exposures separated by hours

or days, these images were often separated

by months or even years, containing numerous

points of light from unrelated objects that

needed to be filtered out. After identifying

the object in DES data, the team confirmed

its existence by locating it in another

public data set from the Canada France

Hawaii Telescope. In total, they

found 19 observations of the object spanning

from 2011 to 2017, all

showing it exactly where their orbital

calculations predicted. The extreme

elongation of 2017 of

201's orbit means it's only visible over a

tiny fraction of its journey around the sun,

too faint to detect for more than 99% of its

orbit. This suggests there could be many

more similar objects lurking undetected at

the edges of our solar system. M

Interestingly, this discovery has

implications for the hypothesised Planet X

or Planet nine. Some astronomers have

suggested this unknown planet's gravitational

influence explains the clustered orbits of

certain trans neptunian objects. However,

2017 of 201's

orbit doesn't fit this pattern, potentially

challenging the Planet X hypothesis, though

debate continues among experts about what

this new discovery actually tells us about

our outer solar system.

Next on the story list today. While Europa is

currently an icy world with a subsurface

ocean, its distant future might hold

something remarkable. In about 12 billion

years, when our sun exhausts its hydrogen

fuel and enters the red giant phase of its

evolution, the habitable zone of our solar

system will dramatically shift outward from

its current position. This cosmic

relocation of real estate suitable for liquid

water will eventually encompass Jupiter and

its moons, potentially transforming Europa in

fascinating ways. Researchers estimate that

as the expanding sun grows more luminous,

Europa could develop and maintain a tenuous

water vapour atmosphere for several hundred

thousand years. The process begins with the

Sun's inevitable evolution. After spending

billions of years as a stable main sequence

star, our sun will eventually deplete its

core hydrogen fuel. This triggers the fusion

of heavier elements like helium, causing the

Sun's outer envelope to expand dramatically.

During this red giant phase, the sun will

grow hundreds of times larger than its

current size, engulfing Mercury and Venus

entirely while rendering Earth unless

uninhabitable. However, for the

outer planets, this stellar evolution creates

new possibilities. Computer models suggest

that Jupiter's system will enter the red

giant branch habitable zone in about 12

billion years when it's approximately 2

astronomical units from the expanding sun,

less than half its current distance, Jupiter

itself will likely develop bright water

clouds in its upper atmosphere as it

experiences the increased solar radiation.

More intriguingly, Europa's surface ices will

begin to sublimate under the influence of

both the brighter Jupiter and the expanded

Sun. Much like dry ice sizzling away

in sunlight, Europa's frozen surface will

transform directly from solid to vapour.

While most of this sublimated ice will escape

to space, simulations suggest some

water vapour will remain bound to Europa for

approximately 200,000 years before being

completely lost. During this brief

cosmic window, Europa might actually be

considered habitable. Though whether this

timespan is sufficient for life to emerge and

thrive remains an open question.

This scenario offers valuable insights for

astronomers studying exoplanetary systems

around sun like stars. As we identify more

exoplanets and potentially exomoons,

understanding how these worlds evolve

alongside their ageing stars becomes

increasingly important. The fate of Europa

serves as a model for what might happen to

similar icy worlds in distant star systems.

Now for something pretty rare. In a

remarkable discovery, Chinese astronomers

have identified an extremely rare type of

binary star system that gives us a glimpse

into a fleeting phase of stellar evolution.

Using the 500 metre aperture spherical radio

Telescope, also known as the China Sky Eye,

researchers led by Han Jin Lin from the

National Astronomical Observatories of China

detected a unique pulsar designated

PSRJ 1928 1815.

Located about 455 light years away,

this system features something astronomers

have long theorised but rarely observed a

pulsar whose radiation pulses are

occasionally blocked by its companion star

every few hours. What makes this

discovery particularly special is that the

two stars are actually orbiting inside a

common envelope of hydrogen gas. Pulsars

themselves aren't uncommon. Scientists have

identified nearly 3,500 in our galaxy

alone. These dense stellar remnants form

after massive stars explode as supernovae.

As they rotate, they emit beams of

electromagnetic radiation from their magnetic

poles that sweep across space like lighthouse

beams. When one of these beams crosses Earth,

we detect it as a regular pulse of radio

waves. But the PSR

J1928 1815 system

captures a critical moment in binary star

evolution. In these systems, the heavier star

ages faster and eventually collapses into a

neutron star, or pulsar. Meanwhile, the

smaller companion star loses material to its

dense partner, causing them to share a common

envelope of hydrogen gas for a relatively

short period. Astronomically speaking, the

two stars orbit within this shared envelope.

Over approximately 1,000 years, the neutron

star gradually clears away this envelope,

eventually leaving behind a hot helium

burning star orbiting the neutron star. This

observation provides compelling evidence

supporting long standing theories about how

stars in binary systems exchange mass,

shrink their orbits and eject shared gas

envelopes. Understanding these processes

helps astronomers piece together the complex

puzzle of stellar evolution, neutron star

behaviour, and how such pairs eventually

merge to produce gravitational waves. The

discovery is particularly significant because

binary systems are extremely common in our

galaxy. More than half of all stars

exist as part of binary or multiple star

systems, their gravitational dance shaping

their evolution in dramatic ways. In some

cases, one star's gravity can drag material

from its companion, leading to explosive

events like novae or even supernovae.

With increasingly powerful telescopes like

fast, astronomers hope to find more of these

rare cosmic pairs, further illuminating the

processes that shape stars throughout their

lifetimes and after their deaths.

Finally today, while we've focused much

of our search for extraterrestrial life on

Earth like exoplanets, a fascinating new

study suggests we should broaden our horizons

to include moons orbiting giant planets.

Researchers from Hungary and the Netherlands

have published compelling findings about the

potential habitability of exomoons in the

journal Astronomy and Astrophysics.

Their study, titled Grand Theft

Formation of Habitable Moons Around Giant

Planets, used complex simulations to

investigate how moons form around giant

exoplanets and whether these moons could

support life. The team, led by

Zoltan Denks from the Hun Ren Research Centre

for Astronomy and Earth Sciences, focused

specifically on the formation of large moons

in circumplanetary discs, the rotating

collections of material that remain after a

planet forms. The researchers

examined 461 known giant

exoplanets, modelling how lunar embryos might

grow through collisions within these discs.

Their simulations revealed that moons with

masses between Mars and Earth could form

around planets roughly 10 times the size of

Jupiter, with many potentially habitable.

Perhaps most interestingly, the study found

that the optimal distance for habitable

exomoons is between 1 and 2

astronomical units from their stars.

Beyond this range, tidal heating rather than

stellar radiation becomes the primary heat

source for these moons. This is similar to

what we see in our own solar system, where

moons like Europa and Enceladus likely

harbour subsurface oceans warmed by tidal

flexing rather than direct sunlight. The

simulations also showed that as distance from

the star increases, more moons tend to form,

but their masses become too small to maintain

habitability. Meanwhile, closer to the star,

fewer but more massive moons form, with more

being lost to stellar theft, where the star's

gravity pulls them away from their host

planet. While astronomers haven't

definitively confirmed the existence of any

exomoons yet several candidates have been

identified. The James Webb Space Telescope is

currently examining potential exomoon

candidates. And the European Space Agency's

upcoming PLATO mission may also be capable

of detecting these distant moons.

This research effectively expands our

definition of the habitable zone to include

moons orbiting giant planets. As one

researcher put it, the circumstellar

habitable zone can be extended to moons

around giant planets, potentially multiplying

the number of worlds where we might someday

find evidence of life.

Well, that's all for today's episode of

Astronomy Daily. What an incredible journey

through space we've taken from watching

SpaceX push the boundaries of rocket

technology despite setbacks to discovering

a massive new dwarf planet that was

hiding in plain sight within existing data.

We've peered into the distant future where

Europa might briefly become habitable as our

sun expands, and witnessed the bizarre

spectacle of a pulsar orbiting inside another

star. Perhaps most tantalising is the

possibility that habitable moons may be far

more common than we once thought, potentially

expanding our search for life beyond

traditional Earth like planets. Each

of these stories reminds us that the universe

remains full of surprises, constantly

challenging our assumptions about what's

possible as our tools and techniques for

observation continue to improve. From

powerful radio telescopes like FAST to the

upcoming PLATO mission, we stand on the

threshold of even more remarkable

discoveries. The cosmos is vast and

ancient, yet we're learning new things about

it every day. Thank you for joining me on

Astronomy Daily. I'm Anna, and I'll see

you again tomorrow as we continue to explore

the wonders of our universe together. In the

meantime, keep looking up in wonder.

In this episode