NASA's Lunar Reactor Race, Earth's Crater Mystery, and the Search for Habitable Worlds

Anna: Welcome to Astronomy Daily, your go to

podcast for the latest and greatest in space

and astronomy news. I'm Anna.

Avery: And I'm, um, Avery. We're so glad you could

join us today as we dive into some truly

fascinating developments from across the

cosmos and right here on Earth.

Anna: That's right, Avery. Today we're going to be

talking about NASA's ambitious plans for a

nuclear reactor on the moon, a surprising new

study that redates Earth's oldest impact

crater, and a breakthrough discovery of a

potentially habitable super Earth.

Avery: We'll also cover the crucial sunshield

installation on the Nancy Grace Roman Space

Telescope, preparing it to give us an

unprecedented look into the infrared

universe. So buckle up because we've got a

lot of exciting news to discuss. Let's get

started.

Anna: First up, let's talk about NASA's

incredibly ambitious plans to power our

future lunar outposts. Its it seems the

agency is really kicking things into high

gear when it comes to getting a nuclear

reactor on the Moon.

Avery: That's right, Anna. For a few years now, NASA

has been working on a 40 kilowatt fission

system, aiming for a launch by the early

2000-30s. But now interim NASA chief

Sean Duffy is pushing for an even more

aggressive timeline and a more powerful

system.

Anna: That's a significant jump. Politico

reported that Duffy's new directive, which

was set to be released recently, orders the

agency to solicit industry proposals for a

massive 100 kilowatt nuclear reactor

to launch by 2030. This is seen as a

critical step for the Artemis program, which

aims to return astronauts to the lunar

surface and establish permanent bases there

around the same time.

Avery: And nuclear power is truly essential for that

vision. Solar energy simply isn't a great

option for a crewed outpost because the moon

rotates so slowly. Slowly, a lunar night can

last about two Earth weeks, which means no

sunlight for an extended period. Nuclear

power provides consistent, reliable energy,

regardless of day or night.

Anna: It's not just about practicality, though.

There's a strong strategic element at play

here. China also has plans to set up a moon

base, partnering with Russia and other

nations. Duffy's directive is very much

geared towards beating China to the punch.

Avery: The directive even highlights the

geopolitical implications, stating that the

first nation with a moon reactor could

declare a keep out zone, which would

significantly inhibit other nations,

including the United States. It's clear that

the race for lunar resources and presence is

heating up.

Anna: Absolutely. This really underscores the

importance of reliable long term power

sources for establishing a sustainable human

presence beyond Earth and the strategic

advantages that Come with it. It's a

fascinating blend of science, engineering and

international relations.

Avery: Moving from the Moon to our own planet.

There's a fascinating new development about

Earth's oldest known impact crater. It turns

out our geological clocks sometimes need a

recalibration. And that's exactly what

happened with the Moraga impact structure in

Western Australia.

Anna: That's right. This site in the remote Pilbara

region made headlines previously with a

different group claiming it was Earth's

oldest impact crater, formed about 3.5

billion years ago and incredibly over 100

kilometers in diameter. If true, that

would have been a game changer for

understanding early Earth.

Avery: But as it turns out, new research published

in Science Advances tells a different story.

While they agree it was an ancient meteorite

impact, this new study concludes the impact

actually happened much later, sometime after

2.7 billion years ago and possibly

even more recently. That's at least 800

million years younger than the earlier

estimate.

Anna: And the size estimate is drastically

different, too. The new study determined the

crater was much smaller, only about 16

kilometers in diameter, a, uh, far cry from

the original 100 plus kilometers. This

means it was too young and too small to have

influenced continent formation or early life,

as was previously speculated.

Avery: So how could two studies investigating the

same site come to such different

conclusions? Both groups found telltale

signs of meteorite impact shatter cones.

These are unique conical imprints of shock

waves that pass through rocks, and their

presence confirms it's an impact site.

The disagreement came down to dating.

Anna: They both used a, uh, geological principle

called the law of superposition,

which states that younger rock layers are

deposited on top of older ones.

The first group found shatter cones within

and below a sedimentary layer known to be

3.47 billion years old, but

not in younger rocks above it, suggesting

the impact happened during that

3.47 billion year period.

Avery: However, the newer investigation found

shattering cones not only in those same

3.47 billion year old rocks, but

also in younger overlying rocks,

including lavas that erupted

2.77 billion years ago.

This crucial detail meant the impact had to

occur after the formation of the youngest

rocks containing shatter cones, placing it

sometime after 2.77 billion years

ago. The precise younger age is still

being worked on with isotopic methods.

Anna: It's a, uh, fantastic example of how science

is a self policing sport. Initial

claims are based on available data, but new

observations can modify or even over.

While Maralga isn't Earth's oldest crater

anymore, it's still scientifically unique

because craters formed in basalt are quite

rare. The basalts there Are the oldest

shocked target rocks known.

Avery: And here's where it gets even more

interesting. Prior to the impact, these

ancient basalts Were chemically altered by

seawater. And nearby sedimentary rocks

Contain some of Earth's earliest well

established fossils. These kinds of rocks

likely covered much of early Earth and, um,

even early Mars.

Anna: This makes the Moralga impact structure A

fantastic outdoor laboratory for planetary

scientists. It's an easily accessible proving

ground for instruments and imagery Intended

for Mars exploration, Helping us understand

the cratered surface and perhaps even early

life on the red planet, all without leaving

Earth.

Avery: From ancient Earth, let's turn our gaze

outwards To a truly exciting breakthrough in

the search for life beyond our planet. A new

detection method has just revealed A

potentially habitable super Earth.

Anna: This is huge. The enduring question of

are we alone? Has driven astronomy for

generations. And discoveries like this bring

us closer to an answer. Since the first

exoplanet Orbiting a sun like star was found

in 1995, the hunt for Earth like

conditions in habitable zones has been a

primary focus.

Avery: And this latest discovery is significant.

An international team led by the Yunnan

Observatories of the Chinese Academy of

Sciences has made a major breakthrough Using

a method called transit timing variation,

or TTV.

Anna: For the very first time, TTV enabled

the detection of a super Earth named

Kepler 725C.

It's truly a monumental find because

this planet is about 10 times the mass of

Earth and orbits within the habitable zone of

its size. Sun like star Kepler's

725. Their findings were just

published in Nature Astronomy.

Avery: Additionally, astronomers have relied on the

transit method or radial velocity

measurements to detect low mass planets,

those 10 Earth masses or less,

Especially in habitable zones. But these

smaller planets usually have long orbits and

produce very weak radial velocity

signals, Making them incredibly difficult

to spot.

Anna: The transit method also has its challenges.

It only works if the planet's orbit uh,

aligns perfectly with our line of sight,

which is uncommon for planets with long

orbital periods. Even if they do align,

the light changes can be too dim and brief to

be confidently identified, Meaning many

potential discoveries are missed.

Avery: This is where TTV comes in as a game

changer. Kepler725C is

a non transiting planet, Meaning it doesn't

pass directly in front of its star. From our

perspective, the team successfully inferred

its mass and orbital parameters by analyzing

the TTV signals of Kepler

725B, a gas giant in the

same system that does transit.

Anna: Kepler's 725C orbits a AH

G9V host star with a period of

207.5 days. It

receives roughly 1.4 times the

solar radiation that Earth does, Placing it

within the host star's habitable zone for

part of its orbit, which definitely makes it

a strong candidate for habitability.

Avery: What's so revolutionary about the TTV

technique Is that it doesn't require a dead

on orbit or rely on those super high

precision radial velocity measurements. This

makes it uniquely suited for detecting those

small, long period, non transiting

habitable planets that are otherwise

extremely difficult to discover.

Anna: It fills a critical gap in our current

exoplanet detection methods. Based on this

study, missions like the European Plato

and Chinese ET or Earth 2.0

missions, once operational, are expected

to greatly enhance our ability to

detect a second Earth. It's a huge

leap forward in the search for another

habitable world.

Avery: Speaking of advanced technology Pushing the

boundaries of discovery, let's talk about the

Nancy Grace Roman Space Telescope.

Technicians at NASA Goddard Space Flight

center have been busy installing crucial

components like the solar array, uh,

sunshield.

Anna: That's right. This shield, made up of six

panels covered in solar cells, is essential.

It's designed to provide the observatory with

power while simultaneously keeping its

sensitive instruments cool throughout its

mission. This marked a major milestone,

Completing the telescope's outer section.

Avery: And just recently, NASA announced they

finished installing the two panels of the

lower instrument sunshade on Roman's inner

inner segment, along with the solar array sun

shield and the deployable aperture cover,

which is essentially its visor. These shields

are absolutely critical for Roman's mission

to explore the infrared universe.

Anna: It's very similar to Webb's sunshield.

Roman's sunshades and aperture cover will

protect its instruments from the heat and

light from the sun, which would otherwise

interfere with its ability to detect those

incredibly faint signals from deep space.

Avery: Conrad Mason, an aerospace engineer at NASA

Goddard, Described them as basically giant

aluminum sandwiches. They're made with metal

sheets as thin as a credit card on the top

and bottom with the honeycomb structure in

the middle. This design makes them stiff, yet

lightweight. And specialized polymer film

blankets Help temper heat transfer from the

sun Facing side to the back.

Anna: Matthew Stevens, another aerospace engineer

at NASA Goddard, Was perfectly summed it up,

saying this shield is like an extremely

strong sunblock For Roman's sensitive

instruments. He also mentioned that the

deploying mechanisms have dampers Similar to

soft close hinges, so the panels won't

slam open. They take about two minutes to

move into their final positions. And this

will be the very first system Roman deploys

in space.

Avery: After launch, with the inner segment fully

assembled, it's now undergoing a 70 day

thermal vacuum test to ensure full

functionality under simulated space

conditions. After that, the inner and outer

segments will be integrated by November, with

a launch expected between fall 2026 and

May 2027.

Anna: The Roman Space Telescope, named after Nancy

Grace Roman, NASA's first chief of astronomy,

is often called the mother of the Hubble

Space Telescope as its direct successor.

Once operational, it will use its thermal

optics to investigate exoplanets, planet

forming disks, red dwarfs, brown dwarfs

and other unseen objects.

Avery: It's also going to observe distant galaxies

to measure the universe's expansion rate, the

Hubble constant, which we've talked about

before. The hope is that it will shed light

on some of the most pressing mysteries in

astronomy and cosmology, including dark

matter, dark energy, and the Hubble tension.

Truly a telescope poised to redefine our

understanding of the cosmos.

Anna: And that brings us to the end of another

fascinating episode of Astronomy Daily.

What a journey through the cosmos we've had

today.

Avery: Absolutely, anna. Uh, from NASA's

ambitious plans to build a nuclear reactor on

the Moon and the strategic race with China

to unraveling the true age of Earth's

ancient Maralga impact crater.

Anna: And let's not forget the exciting discovery

of Kepler 725c, a potentially

habitable super Earth found using that

innovative transit timing variation method.

Method it really boosts our search for Earth

2.0.

Avery: And of course, the progress on the Nancy

Grace Roman Space Telescope with its crucial

sun shields getting installed, preparing it

to peer into the infrared universe and help

solve mysteries like dark matter and dark

energy.

Anna: It's been an incredible day of space news and

we hope you enjoyed joining us for all the

updates. Thank you for tuning in to ASTRONOMY

Daily.

Avery: We love sharing these cosmic stories with

you. Until tomorrow, stay curious and

keep looking up.

In this episode