An Atmosphere That Shouldn't Exist + 12,000 Artemis II Photos

0:00 Anna: Welcome to Astronomy Daily, your daily guide

0:02 to what's happening across the universe. I'm

0:05 Anna.

0:06 Avery: And I'm avery. It's Wednesday 6th

0:08 May, 2026. Series 5 Episode

0:11 97 Big show today Avery.

0:14 Anna: We've got a world beyond Pluto that has

0:17 absolutely no right to have an atmosphere.

0:19 And yet there it is.

0:21 Avery: A rule breaker in the Kuiper Belt. I love it.

0:24 We've also got 12,000 photographs from

0:26 Artemis 2 landing on the Internet. And a

0:29 quick look at where Artemis 3 is headed.

0:31 Anna: Blue Origin's moon lander gets a very tough

0:34 test. The sun turns out to be tidying up

0:37 our orbital clutter. Drones could be the key

0:39 to finding water on Mars.

0:41 Avery: And a certain comet has done a handover.

0:44 Northern skies, it's been emotional. Southern

0:47 skies, Here it comes.

0:48 Anna: Let's go.

0:49 Avery: Alright, let's start with what might be my

0:51 favorite story of the week. There is a little

0:53 frozen world out beyond Neptune. A, uh, Trans

0:56 neptunian object designated

0:58 2002 XV93.

1:01 And it appears to have a thin atmosphere.

1:04 Anna: Which sounds nice, except that this object is

1:07 only about 500km across. Way

1:10 too small to hold an atmosphere.

1:12 Avery: Exactly. The scientific understanding has

1:14 always been that small icy bodies in the

1:17 outer solar system just can't retain gases.

1:20 They're too cold, their gravity is too weak.

1:22 Pluto is the one exception. And Pluto is a

1:25 dwarf planet. This thing is much smaller.

1:28 Anna: So how did they find it?

1:29 Avery: Stellar occultation. The team led by Dr.

1:32 Ko Adematsu at the National Astronomical

1:35 Observatory of Japan watched as

1:37 2002 XV93 passed

1:40 in front of a distant star. If there's no

1:43 atmosphere, the star disappears instantly.

1:45 Instead, the light faded gradually. That

1:48 gradual change is the signature of an

1:50 atmosphere bending the starlight.

1:53 Anna: So what created the atmosphere? Do we know?

1:56 Avery: Two leading theories. One is cryovolcanism,

1:58 basically ice volcanoes venting internal

2:01 gases. The other is a relatively recent

2:04 comet impact that blasted material into

2:06 space. If it's the latter, the atmosphere

2:09 could disappear within a thousand years. We

2:11 might be looking at this at an extremely

2:13 lucky moment.

2:14 Anna: Cosmically lucky. And the James Webb

2:17 Telescope could potentially work out what the

2:19 atmosphere is actually made of.

2:21 Avery: That's the plan. Webb could detect the

2:23 chemical signature it. And if the density is

2:25 dropping over the next few years, that would

2:27 point to the impact theory. If it stays

2:29 stable, it's probably cryovolcanism, an

2:32 ongoing process.

2:33 Anna: What I love about this is that it's not just

2:35 interesting, it actively changes the

2:38 rulebook. If even this small world can hold

2:41 an atmosphere, even temporarily. The Kuiper

2:44 Belt could be a much more dynamic place than

2:46 we thought.

2:47 Avery: Dr. Adimatsu put it. This challenges the

2:50 conventional view that small icy worlds in

2:52 the outer solar system are mostly inactive

2:55 and unchanging. And I think that's the story

2:57 here. The outer solar system is alive.

3:00 Anna: So the Artemis 2 mission ended almost a month

3:03 ago. But the images just keep coming.

3:06 Avery: They really do. NASA has quietly

3:08 uploaded more than 12,000 photographs taken

3:11 during the mission. The full archive is now

3:13 publicly accessible on the Gateway to

3:16 Astronaut Photography ofearth website.

3:18 Anna: 12,000, that's a lot of scrolling.

3:21 Avery: It is, though. Fair warning, some of them are

3:24 duplicates or near identical frames. But even

3:27 filtering for the standouts, there is

3:29 extraordinary material in there. Close ups of

3:31 the lunar farside that are the highest

3:33 resolution images ever taken by a human hand.

3:37 Star trails, Earth vanishing behind the moon.

3:39 The Earth set shots, and they were

3:42 Anna: shot on a combination of professional Nikon

3:45 cameras and modified iPhone 17s.

3:48 The crew left all the photos unattributed. A

3:50 deliberate decision to frame it as a shared

3:53 human achievement, which I think is lovely.

3:55 Avery: And NASA says the archive isn't just for

3:58 public enjoyment. It's a foundational data

4:00 set for Artemis 3 mission planning. These

4:02 images will help determine where to land, how

4:05 terrain looks under different lighting

4:06 conditions and more.

4:08 Anna: Speaking of Artemis 3, any update on that

4:11 front?

4:12 Avery: Yes, actually. The Artemis 3

4:14 Space Launch System core stage arrived at

4:17 Kennedy Space center by Barge on April

4:20 28th. It's now in the vehicle assembly

4:22 building. The mission is targeting

4:24 mid-2027. And the plan, as

4:27 confirmed recently, is to launch into a

4:30 460 kilometer low earth orbit

4:33 to test docking between Orion and at

4:35 least one of the commercial lunar landers.

4:38 That's the critical rehearsal before Artemis

4:41 4 attempts the actual moon landing in

4:43 2028.

4:45 Anna: So we went from zero humans on the moon since

4:48 1972 to Artemis II,

4:50 flying a crew around the far side to already

4:53 stacking the next rocket. It's been quite a

4:56 run.

4:57 Avery: It really has.

4:58 Anna: Blue Origin's Blue Moon Mark one lunar

5:01 lander nicknamed Endurance has completed its

5:04 thermal vacuum testing at NASA's Johnson

5:06 Space Center. What does that actually

5:08 involve?

5:10 Avery: So thermal vacuum chamber A at

5:12 Johnson is essentially a 90 foot tall

5:15 can that sucks out out all the air and then

5:18 cycles through extreme temperatures,

5:20 simulating what a spacecraft will encounter

5:22 in space and near the moon. You're recreating

5:25 the environment of deep space right there on

5:28 the ground in Houston.

5:29 Anna: And Endurance passed.

5:31 Avery: It did, which is a significant

5:34 milestone because MK M1 is scheduled to

5:36 fly to the moon's south polar region later

5:39 this year. It's an uncrewed cargo

5:41 lander. No people on board, but it's carrying

5:44 a couple of interesting science payloads.

5:47 Anna: What are those?

5:48 Avery: There's a stereo camera array specifically

5:50 designed to photograph the engine plume

5:53 interacting with the lunar surface during

5:54 descent. That might sound niche, but it's

5:57 actually really important. Understanding how

6:00 rocket exhaust disturbs the regolith helps

6:02 you design safer landing approaches for

6:04 crewed missions. The other payload is a

6:07 laser retroreflector, which helps orbiting

6:10 spacecraft precisely locate the lander.

6:13 Anna: And there's a bigger picture here. MK1 is

6:15 a pathfinder for MK2, the crewed version that

6:18 Blue Origin is developing for future Artemis

6:21 missions.

6:22 Avery: Right. Every lesson learned from MK1 feeds

6:25 directly into that. In the commercial lunar

6:28 lander space, you really can't afford

6:30 surprises when there are humans on board.

6:33 Anna: Alright, moving on. New research published

6:35 today in Frontiers in Astronomy and Space

6:38 Sciences has confirmed something scientists

6:40 have long suspected. Solar activity

6:43 directly affects how quickly space debris

6:46 falls back to Earth.

6:47 Avery: Walk us through it. How does the Sun's

6:50 activity move things in orbit?

6:52 Anna: So the sun goes through an 11 year cycle of

6:55 activity. At the peak, it's pumping out more

6:57 radiation, which heats Earth's upper

7:00 atmosphere, the thermosphere, causing it to

7:03 expand. Low Earth orbit suddenly becomes

7:06 a slightly thicker air environment.

7:08 Objects passing through it experience more

7:11 drag, which slows them down, lowers their

7:13 orbit, and eventually brings them back.

7:16 Avery: And the new study tracked this happening in

7:18 practice?

7:19 Anna: Yes. Ayesha Ashraf and colleagues at

7:22 India's Vikram Sarabhai space center

7:25 tracked 17 pieces of debris over

7:27 38 years through three complete

7:30 solar cycles. They found a really clear

7:33 threshold effect. Once sunspot numbers hit

7:36 roughly 70% of the cycle's peak, the

7:38 debris started dropping noticeably below that

7:41 threshold. The objects held their altitude

7:44 above it. They steadily descended, a

7:46 staircase pattern tied directly to the solar

7:49 cycle.

7:50 Avery: So the sun is naturally clearing some of the

7:52 junk for us.

7:53 Anna: In a sense, yes. And, um, the timing

7:56 matters enormously. We're currently near the

7:59 peak of Solar Cycle 25, which means right

8:02 now is actually a period of accelerated

8:05 orbital decay for a lot of debris. For

8:07 mission planners dealing with the growing

8:09 threat of collisions in low Earth orbit,

8:12 understanding this cycle and knowing when the

8:15 sun is most actively doing its housekeeping

8:17 could be operationally very valuable.

8:20 Avery: It's one of those stories where the universe

8:22 turns out to be more interconnected than

8:24 you'd expect.

8:25 Anna: Always is. Now, before we move on, a quick

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8:42 did.

8:43 Avery: Next up, Mars has hidden ice. We've known

8:46 that for years. But the challenge is finding

8:48 exactly where it is with enough precision to

8:51 actually use it. A new study says

8:54 radar equipped drones could be the answer.

8:56 Anna: Yes, this is from a study published in the

8:59 Journal of Geophysical Research. Planets.

9:02 Mars has what are called debris covered

9:04 glaciers at its mid latitudes. Basically

9:07 huge reservoirs of water ice buried under

9:10 a blanket of rock and dust. That rock

9:13 actually protects the ice from sublimating

9:15 away into the thin Martian atmosphere.

9:17 Avery: And um, the orbital radar CHARAD on the Mars

9:20 Reconnaissance Orbiter can see the ice is

9:23 there, but can't resolve the exact boundary

9:25 between ice and overlying debris.

9:28 Anna: Exactly. CHAROD operates from orbit and

9:31 the resolution just isn't fine enough for

9:33 that kind of precision. What the researchers

9:36 proposed is flying a low altitude drone with

9:39 a ground penetrating radar to map from much

9:42 closer up. They tested this concept on Earth

9:45 over a rock glacier in Wyoming and the drone

9:47 could see that boundary clearly.

9:49 Avery: And ingenuity already showed us that powered

9:52 fly on Mars is possible.

9:54 Anna: That's the key precedent. A radar equipped

9:57 successor drone doing subsurface science

9:59 rather than just aerial photography is a

10:02 completely logical next step for any future

10:05 human mission that relies on in situ water.

10:08 And they probably will. This kind of precise

10:11 ice mapping ahead of time could be genuinely

10:13 mission critical.

10:15 Avery: Finding your water supply before you arrive

10:17 rather than hoping for the best.

10:19 Anna: Exactly. Scout ahead. It's what

10:21 explorers have always done.

10:23 Avery: And we close today with a handover. Comet

10:26 C 2025 R3 Pan

10:29 Starrs is done with the Northern Hemisphere

10:31 and it's now arriving for southern skies.

10:34 Anna: For our listeners in Australia, New Zealand,

10:37 South Africa, South America, this is your

10:40 moment.

10:40 Avery: The comet passed perihelion on April

10:43 19 when it came within about 75

10:46 million kilometers of the sun. It may have

10:49 briefly reached naked eye visibility around

10:51 that time. It's now fading, but it's also

10:53 moving away from the sun in the sky, which

10:56 makes it much easier to actually observe.

10:58 Anna: And there are some genuinely exciting deep

11:01 sky encounters coming up. From May 10th to

11:04 the 12th, C 2025 R3

11:07 will pass within about 2 degrees of the Orion

11:09 Nebula. For anyone with a telescope or even

11:12 decent binoculars, that pairing is going to

11:15 be something special to photograph.

11:18 Avery: How bright is it now?

11:19 Anna: Fading, but still a solid binocular target.

11:22 The absolute best conditions will be around

11:24 the new moon on the 16th of May. That's when

11:27 the skies will be darkest. Look low in the

11:30 western sky after sunset. Lear Horizon

11:33 is your friend.

11:34 Avery: And, um, is it worth the effort? If you're a

11:36 casual observer rather than a dedicated

11:38 astronomer, I'd say yes.

11:40 Anna: Because this comet is on a hyperbolic

11:42 trajectory, it is not coming back.

11:45 Once it leaves, it's gone from our solar

11:47 system forever. There's something quite

11:50 remarkable about that, looking at it in the

11:53 sky, knowing you're watching a one way

11:55 journey.

11:56 Avery: A visitor from the deep that won't pass this

11:58 way again.

11:59 Anna: Exactly. Go see it while you can.

12:02 Avery: And that's Astronomy daily for Wednesday, 6

12:05 May 2026. Series 5

12:07 Episode 97 what a lineup today.

12:11 Anna: From a frozen world growing an impossible

12:13 atmosphere to 12,000 photographs from

12:16 the moon to a comet making its southern

12:19 debut.

12:19 Avery: If you enjoyed the show, please subscribe and

12:22 leave us a review wherever you listen. It

12:24 genuinely helps more people find us.

12:26 Anna: You can find us online at astronomydaily

12:29 IO and follow us on social

12:31 media@astrodaily. Pod.

12:33 Avery: I'm Avery.

12:34 Anna: And I'm Anna. Keep looking up.

12:39 Avery: Mhm. Home.