Mars Rover's Quest, Tesla's Orbital Fate, and a New Quasi Moon Discovery

Steve Dunkley: Welcome to Astronomy Daily for another

episode. I'm Steve Dunkley, your host. It's

the 15th of September 2025.

Voice Over: With. Your host, Steve Dunkley.

Steve Dunkley: Yes, and getting straight back into it.

Welcome to the 15th of September 2025.

Wow. This year is just skipping by.

And what a crazy year it's been. Welcome

back, Hallie.

Hallie: Good to be back.

Steve Dunkley: Well, Hallie, I don't know about you, but I'm

feeling the need.

Hallie: The need to with it, perhaps.

Steve Dunkley: Oh, well, yes. I was going to do a bit of a

movie line, but yes, I guess that's the

essence of it, Hallie. Yes.

Hallie: Terrific.

Steve Dunkley: All business today then, Hallie. Okay, well,

the archiving is nice and neat, I see. Yes,

you have been busy. And the Astronomy Daily

newsletter has provided another stack of

fresh takes. So we can just get going, I

guess.

Hallie: That's perfectly fine with me, my favorite

human.

Steve Dunkley: Well, righty o then.

Hallie: Let's get on with it.

Steve Dunkley: Well, you are all business, Hallie.

Hallie: With my supercomputer algorithmic thought

processors. I'm already way ahead of you.

Steve Dunkley: Well, of course you are.

Hallie: I knew you were going to say that. Yes, of

course you did, silly human.

Steve Dunkley: I could do this all day.

Hallie: Okies, let's go.

Steve Dunkley: Hit it, machine girl.

Hallie: Last week, the Perseverance rover began an

exciting new journey. Driving

northwest of the Soya Ridge,

Perseverance entered an area filled with a

diverse range of boulders that the science

team believes could hold clues to Mars early

history. The terrain we are exploring

is known as Megabreccia, a chaotic mixture of

broken rock fragments likely produced during

ancient asteroid impacts. Some

blocks may have originated in the gargantuan

Isodus impact event, which created a

1200 mile wide crater, or about

1930km just

east of Jezero. Studying Mega

Breccia could help us link Jezero's geology

to the wider region around Isidis Basin,

tying local observations to Mars global

history. The rover is now beginning

a systematic exploration of these rocks

starting at Scotia Felit. If they

are truly mega Breccia, they could contain

pieces of deep crustal material, offering a

rare glimpse into Mars interior.

These rocks likely predate the deltaic and

volcanic deposits we explored earlier in

Jezero Crater, making them some of the oldest

accessible rocks Perseverance will ever

encounter. They may therefore reveal

to what extent water was present on ancient

Mars. A key question as we continue our

search for signs of past life on the Red

planet. In short, by venturing

into this jumbled terrain, Perseverance is

giving us a front row seat to the Earliest

chapters of Mars story. You're

listening to Astronomy Daily.

Steve Dunkley: The probability of the Tesla Elon

Musk launched into space will hit the Earth,

or whether or not a Tesla will land on Earth

from space isn't something we normally be

thinking about. But after Elon Musk

actually launched one into space in 2018, it

is something that some people are apparently

contemplating. You may recall back six years

ago the famous Tesla Roadster being launched

into space on a rocket. And since then the

Tesla has traveled approximately

15,715 miles per

hour and covered a distance that would be the

equivalent of orbiting the sun four times

over. But now that it's out in space, is

there any risk of that Tesla falling back to

Earth? Believe it or not, some scientists

have already looked into this very question.

In 2018, a study published in

the journal Aerospace. Yes, they've actually

published the results. Some researchers

likened the Roadster to an asteroid.

The Roadster bears many similarities to Near

Earth asteroids or NEAs, which diffuse

through the inner solar system chaotically.

Though repeated close counter encounters with

the terrestrial planets and the effects of

mean motion and secular resonances.

A uh, lot of technical talk, meaning that

they come close sometimes to uh,

the planets. Initially, NEAs reach their

uh, orbits from the more distant main

uh built via strong resonances such as

secular V, uh6 resonance or

the strong 3.1 mean motion resonance with

Jupiter. How's that?

When entering these escape routes, many

NEAs are driven into nearly

radial orbits that plunge into the Sun. And

this would put NEA uh chances of colliding

with a UH planet very low at around

2%. But the Roadster is slightly

different. The 2018 article

continued that the initial Tesla ah,

orbit grazes that of Earth

uh, so one might expect an initial

period of enhanced collision probabilities

with Earth before it is randomized into a

more NEA like trajectory. It's

therefore unclear whether the Tesla uh is

likely to diffuse into

distant strong resonances and meet the same

fate as the wider NEA UH population or

whether it would first strike one of the

terrestrial planets. The researchers

estimated that the Tesla would draw closest

to Earth in 2047, when it

will come within 3.1 million miles of us.

After 100 years it becomes

impossible to make long term predictions.

But that didn't stop the team from producing

this statistic. They stated, however,

using an ensemble of several hundred

realizations, they were able to sustain

statistically determine the probability of

the Tesla colliding with the solar system

planets on astronomical timescales. With

this longer timescale in mind. They estimated

that there was a 22% chance of the

Tesla hitting Earth. The researchers

didn't exactly put a date on it, but at least

we can relax, given that this is on a

timescale of millions of years and that we

shouldn't lose any sleep over a Tesla landing

on top of us anytime soon.

Hallie: You're listening to Astronomy Daily, the

podcast with Steve Dunkley.

Something has just been discovered, but it's

been orbiting the sun alongside Earth for

decades and will continue to do so for

decades more. Our home planet just

got a new companion, or at least a newfound

one. We know the Earth only has one

true moon, but we've also known for a

while that our planet is currently

accompanied by seven other small asteroids

that seem to circle around us, even though

they don't really orbit Earth as a true moon

would. These objects, known as

quasi moons, tend only to inhabit Earth

accompanying orbits for short periods, years

or decades, sometimes centuries.

Now it turns out there's a new quasi moon in

town. Just discovered on August

29 by the Pan Starrs Observatory on

Haleakala, Hawaii, asteroid

2025 PN7 was quickly confirmed by

other observatories. Earlier

images of the object extend back to

2014. It now

appears to have been on a quasi moon orbit

for about 60 years, and it will remain so for

about 60 more. Eventually,

though, it will revert to a horseshoe orbit,

one that brings it periodically close to

Earth, only to back away again, never

completing a full circle around our planet.

Alan Harris of Space Science Institute, in a

posting on the Minor Planet's mailing list,

writes that its velocity relative to Earth of

3.4 kilometers per second, or

7,600 miles per hour, is higher

than would be expected from lunar ejecta.

He adds that it's most likely just an

asteroid that has trickled into a near Earth

orbit from the inner main belt. At

some point in the future, gravitational

interactions may eject it from Earth's

vicinity altogether. Some future

close encounter with Earth could put it on an

orbit that intersects either Mars or Venus or

both, harris writes.

Indeed, simulations carried out by French

journalist and amateur astronomer Adrian

Coffinit, who was the first to post on the

MPML group that this object is a quasi moon

of Earth, show that indeed this object is

likely to cross Mars's orbit at some point,

although that event is likely thousands of

years in the future.

Steve Dunkley: Thank you for joining us for this Monday

edition of Astronomy Daily, where we offer

just a few stories from the now famous

Astronomy Daily newsletter, which you can

receive in your email every day just like

Hallie and I do. And to do that, just Visit

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Space, Space, Science and

Astronomy Foreign

proposes a flyby mission to the asteroid

UH apophis during the 2029 Earth

uh encounter. Chinese scientists are uh,

proposing using a Pathfinder spacecraft

to make a flyby of asteroid Apophis

when it makes a close approach to Earth in

2029. The team behind the concept are

proposing a Pathfinder spacecraft flyby

of the asteroid Apophis during its close

approach to Earth uh in that year,

leveraging a proposed mission to deploy

asteroid spotting spacecraft in Venus like

orbits. The mission would consist of two

small satellites sent into a halo

orbit around the Sun Earth Lagrange point

1 to await the approach of Apophis

and transfer into a flyby orbit so as

to meet the asteroid shortly after its close

encounter with the Earth. The asteroid is due

to pass within the geosynchronous orbit belt

on Friday, April 13,

2029. The Crown Apophis

concept tags onto a proposed

asteroid Surveyor mission. That mission,

named CROWN and for which the preliminary

design is completed, would consist of six

heterogeneous wide field near Earth surveyors

in Venus like heliocentric

orbits and proposed to substantially improve

improve the searching and tracking of NEAs.

It would, if approved, form part of China's

asset for a planned comprehensive planetary

defense program. The science

objectives of Crown Apophis, according to

Zhang Yi of Sun Yat Sen University,

who presented the proposal at the

Europlanet Science Congress and Division for

Planetary Sciences joint session in

Helsinki September 8, would be to measure

the fundamental properties of potentially

hazard asteroids and the effect of

its close encounter with the planet Earth. It

would aim to observe how the movement of

material on Apophis is induced any dust

activity and how it interacts with the

terrestrial magnetosphere. The larger

44 kilogram spacecraft would use

combined chemical and ion propulsion

and carry a narrow angle camera,

microwave ranging Doppler system, a four

formation monitoring camera and a low

frequency radar. An 8 kilogram

CubeSat would carry some of the same

systems as the main spacecraft. This is a

very rare opportunity for planetary science

and there are many parties already

proposing missions or concepts and so we

don't want to miss this opportunity in China,

salee said. Launch is proposed to

be a yet to be identified rideshare mission

to geosynchronous transfer orbit and then

the spacecraft would slowly raise to reach

its L1 position. We hope to

coordinate with and complement other

missions including Ramses Destiny plus and

Osiris Apex, lee said, referring to

respective missions from the European Space

Agency, Japanese Aerospace Exploration

Agency and NASA, which are in different

stages of development, funding and operation.

In the latter case, Michael Nolan, who is the

deputy principal investigator of Osiris uh,

Apex stated in an earlier presentation on

the mission that congressional language in a

bill not yet passed includes funding for

Osiris Apex. Ramses faces

its own funding decision in November at an

ESA ministerial. Other smaller class missions

in the US and Europe are UH being proposed.

The value of multiple missions could be very

high, according to scientists at

EPSC dps. It's going to

enhance our scientific returns such as

cross verification and comparison. The

results provide scientific context to each

other and provide redundancies, lee said.

He added that the team, based in Macau, has

international partners from Brazil, Uruguay,

Spain and France, but is also seeking

further cooperation, which would likely

benefit the mission's chances of gaining

approval, possibly by the end of the year.

It is also looking at commercial avenues to

make the mission happen. Li was also involved

in another Chinese rapid response proposal to

study 99942 Apophis Ah, which

would have employed a swarm of cubesats

to make multiple flybys. China

is meanwhile working towards its first

planetary defense mission, a kinetic impactor

with a combined Surveyor spacecraft expected

to launch around 2027. The country

also launched a near Earth UH asteroid sample

return mission, Changwen 2 in

late May. China's first space mission

to an asteroid was flyby of the asteroid

tutalis in 2012, conducted by

repurposing the Chang' E2 lunar

orbiter for an extended mission.

Hallie: You're listening to Astronomy Daily, the

podcast with your host Steve Dudley.

A AH distant supernova exposed elements from

a star's core. The result

reshapes ideas of how massive stars

evolve. For the first time,

astronomers have seen the inner layers of a

star revealed in its final moments.

According to long standing theory, stars are

built in layers like onions, with each layer

composed of different elements that grow

heavier toward the core. While this

model is widely accepted, directly observing

a star's deeper layers has been nearly

impossible until now.

Astronomers using the Keck Observatory in

Hawaii have collected spectroscopic data from

a supernova first identified by the Zwicky

transient facility in 2019.

The event, designated

SN2021YF, occurred

2.2 billion light years away.

The Keck observations revealed ionis,

silicon, sulfur, and argon elements

never before detected in a supernova because

they are normally hidden beneath outer

layers. The finding supports some

theoretical predictions about the structure

of exploding stars, but also raises new

challenges. It is well established

that massive stars shed material from their

outer layers as they near the point of

collapse into a supernova. This

process has been documented many times, and

the new data confirm it again.

However, SN2021YF appears to

have lost far more material than any star

observed before leaving astronomers to

reconsider how extreme this stripping process

can be. The observations are

presented in a new paper titled A Cosmic

Formation Site of Silicon and Sulfur Revealed

by a New Type of Supernova Explosion.

The lead author is Steve Schulz, a UH

research associate at Northwestern

University's center for Interdisciplinary

Exploration and Research in Astrophysics.

This is the first time we have seen a star

that was essentially stripped to the bone,

said lead author Scholz. It shows

us how stars are structured and proves that

stars can lose a lot of material before they

explode. Not only can they lose their

outermost layers, but they can be completely

stripped all the way down to the core and

still produce a, um, brilliant explosion that

we can observe from very, very far distances.

Steve Dunkley: And there we have it, ladies and gentlemen,

another episode of Astronomy Daily in the

can. I hope you enjoyed the stories that we

have for you today off the Astronomy

Daily newsletter, which you can receive in

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you go ahead and do that because there's lots

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interesting. Hallie and I get our information

every day just like that, and I hope you do

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of Astronomy Daily. I'm live, she's

an AI, and she gives me heaps.

Okay, so we'll hope to see you then. Have a

great week and we'll catch you on the flip

side. Bye, everybody. Bye.

Voice Over: With your host, Steve Dunkley

In this episode