Nuclear Power in Space, Planetary Defense Insights, and an Aurora Alert for Northern Skies

0:00 Anna: From nuclear powered satellites to a, uh,

0:02 thruster that never runs out of fuel. This is

0:05 Astronomy Daily.

0:06 Avery: I'm Avery.

0:07 Anna: And I'm anna. It's Wednesday, July 8,

0:10 2026, and this is season five, episode

0:13 135.

0:14 Avery: Big show today, Anna. We've got a genuine

0:17 technology first, a Kiwi engineering trick

0:20 that sounds almost too clever to be true. A

0:22 plot twist five years in the making, and for

0:25 once, a story that isn't about our Southern

0:28 Hemisphere listeners.

0:29 Anna: That's right. Today we're tipping our hat to

0:31 the northern half of our audience, who make

0:33 up the bulk of our listeners, but don't

0:35 always get a sky story written just for them.

0:38 Avery: Plus, a serious look at planetary defense.

0:41 And we close things out with an astronaut

0:43 who's already planning his next chapter just

0:46 weeks after circling the moon.

0:47 Anna: Let's get into it, and let's start with a,

0:49 uh, genuine first.

0:51 On July 7, SpaceX's Transporter

0:54 17 rideshare mission lifted off from

0:56 Vandenberg Space force base, carrying 81

0:59 payloads. And tucked along them was something

1:02 that's never flown before on a commercial

1:04 mission.

1:05 Avery: This is the Bore cubesat, built by a Florida

1:08 company called City Labs. And what makes it

1:10 special is what's powering one of its

1:12 payloads. A tiny nuclear battery.

1:15 Anna: Now, before anyone pictures a miniature

1:17 reactor. This is something much gentler.

1:20 It's called a beta voltaic device. City

1:22 Labs calls the technology nanotritium.

1:26 It takes the beta particles thrown off as

1:28 tritium decays and converts them directly

1:31 into electricity through a semiconductor.

1:33 Avery: The power output is tiny. We're talking micro

1:36 to milliwatts. Not enough to run your kettle.

1:39 But here's the trick. It's continuous day or

1:41 night, in sunlight or in shadow. It just

1:44 keeps producing power.

1:45 Anna: And tritium has a half life of 12.3

1:48 years. So this thing stays effective for 20

1:51 years before it quietly decays into harmless

1:54 helium 3.

1:55 Avery: The FAA had to sign off on this one, too.

1:57 They concluded that public radiation exposure

2:00 from the mission would stay under 1 millirem

2:03 using conservative assumptions. So this has

2:05 been vetted from a safety standpoint, not

2:07 just an Engineering 1.

2:09 Anna: Citilab CEO Peter Kabawi called it a

2:12 historic step for commercial nuclear power in

2:14 space and said it enables, quote,

2:17 persistent always on payload operations

2:20 that are not constrained by sunlight or

2:22 battery life.

2:23 Avery: Worth being? Clear. This isn't like the

2:25 plutonium rtgs powering Voyager or

2:28 New Horizons or the Mars rovers, which

2:30 generate power from heat. This is much

2:33 smaller, much lower power. And it's still

2:35 relying on solar panels for its main Systems.

2:38 This is a proof of concept, but

2:40 Anna: it's a proof of concept with a very specific

2:42 use case in mind. Permanently shadowed

2:45 craters on the moon, for instance, where the

2:47 sun genuinely never reaches. NASA's

2:50 floated tritium beta voltaics as a way to run

2:53 small autonomous sensors in exactly those

2:56 conditions.

2:56 Avery: Solar panels have run space missions for

2:59 seven decades. This is the first real

3:02 commercial attempt at an answer to the

3:04 question, what happens when the sun doesn't

3:07 reach you at all?

3:08 Anna: It's a small battery, but if it scales, it

3:11 opens some very dark corners of the solar

3:13 system.

3:14 Avery: Sticking with clever engineering, this next

3:16 one comes from a lot closer to home for you,

3:18 Anna.

3:19 Anna: It does. This is a New Zealand story. A

3:21 company called Zeno Astronautics, a spinoff

3:24 from the University of Auckland, has just

3:26 completed the first orbital test of something

3:29 called the Super Torquer.

3:31 Avery: And the pitch here is genuinely wild. It's a

3:33 thruster that never runs out of fuel because

3:36 it doesn't use any fuel at all.

3:38 Anna: Here's how it works. The Super Torquer uses

3:41 superconducting magnets powered by the

3:43 satellite's solar panels. And those magnets

3:46 push against Earth's own magnetic field.

3:49 That interaction generates torque enough to

3:51 turn and orient the satellite with zero

3:54 propellant consumed.

3:55 Avery: Superconducting magnets have been on people's

3:57 wish list for this kind of job for years. But

4:00 the hardware was always too big and too

4:02 complicated to fit on a small satellite.

4:04 Miniaturization has finally caught up with

4:06 the

4:07 Anna: idea to be precise about what this replaces.

4:10 It's primarily for attitude control, so

4:13 turning and orientation rather than big

4:15 or get changing maneuvers. It's, uh, a much

4:18 cleaner alternative to the cold gas thrusters

4:20 satellites currently use just to point

4:22 themselves the right way.

4:24 Avery: But if you never need propellant for that

4:26 job, a, uh, satellite's operational lifetime

4:28 stops being limited by how much gas it

4:30 launched with.

4:32 Anna: Dano's own messaging captures the

4:34 ambition nicely. They say they're trying to,

4:37 quote, remove all reliance on

4:39 Earth's resources so that we can build a

4:42 sustainable industry in space. No

4:45 tanks, no valves, nothing to run dry.

4:47 Just magnets, sunlight and the planet's own

4:50 magnetic field doing the work. A very

4:53 kiwi way to solve a very old space

4:56 problem.

4:57 Now to an ongoing story that just took a

4:59 genuine twist. Longtime listeners will

5:02 remember we've been tracking China's Tianwen

5:04 2 mission on its approach to the near Earth

5:07 asteroid Kamaua Lewa.

5:09 Avery: Well, on July 6th, after a 400 day,

5:12 roughly 1 billion kilometer journey,

5:14 Tianwen 2 arrived, settling in at a

5:17 station keeping distance of about 20 km from

5:20 the surface. China's space agency released

5:23 the first close up image the same day.

5:25 Anna: For context on what Kamalalewa actually is,

5:28 it's one of only seven known quasi

5:31 satellites of Earth. It orbits the sun, but

5:34 it stays locked in a stable dance alongside

5:37 our planet and has done so for roughly a

5:40 hundred years, with about 300 more to

5:43 go.

5:43 Avery: The image shows a small asymmetrical rock

5:46 somewhere in the range of 20 to 30 meters

5:48 across. Tiny as these things go.

5:51 Anna: Now, here's where it gets interesting. Since

5:54 2021, the leading theory has been that Kamau

5:57 Lewa is, uh, a genuine chip off our own moon,

6:00 blasted off the lunar far side by the impact

6:03 that created the Giordano Bruno crater

6:06 somewhere between 1 and 10 million years ago.

6:09 That was based on its reflectance spectrum,

6:11 looking a lot like space weathered lunar

6:13 soil.

6:14 Avery: But just five days before Tianwen 2

6:16 arrived, a JWST preprint

6:19 modeled Kamawa Lea's albedo. How

6:22 reflective it is. At 0.59,

6:25 the moon's albedo is only about

6:27 0.12. That's a huge

6:30 mismatch and it's simply not compatible with

6:32 a lunar origin.

6:33 Anna: Astronomer Mikhail Grandvik of the University

6:36 of Helsinki says the new TN12

6:38 image basically confirms the albedo

6:41 result from the JWST data,

6:44 pointing instead toward Kamaualewa being a

6:47 rare type of silicate asteroid

6:49 entirely unrelated to our Moon.

6:51 Avery: For five years, the story was it's a piece of

6:54 the moon. That story might not survive

6:56 contact with

6:57 Anna: the evidence, which is exactly why Tianwen

7:00 2 is there. Over the next year, it'll study

7:02 kamauu Lewa with 11 science instruments

7:05 before attempting to collect somewhere

7:07 between 20 and 100 milligrams of surface

7:10 material using whichever of three sampling

7:13 techniques suits the asteroid surface best.

7:16 Avery: Sample return is planned via an earth flyby

7:19 around April 2027. And only then

7:22 will we really know for certain what this

7:24 little rock is made of.

7:25 Anna: The only way to settle it for good is to

7:27 bring a piece of it home.

7:29 Now staying with asteroids, but shifting from

7:32 origins to defense, because a new study

7:35 out this week tackles a question that sounds

7:37 like it's straight out of a disaster movie.

7:40 Avery: How exactly do you nuke an asteroid if it

7:42 ever comes to that? A peer reviewed paper

7:45 published July 7 in the journal

7:47 Science and Technology models two different

7:50 approaches to nuclear asteroid deflection.

7:53 Anna: Model one is what you'd probably

7:55 an impact detonation. You hit the

7:58 surface, create a shallow crater and

8:00 detonate a nuclear Device there.

8:03 Avery: Mode 2 is more elaborate. A, uh, pre

8:05 excavation Detonation, A penetrator

8:08 device digs a deeper crater first and

8:11 then the warhead goes off inside that

8:14 crater, achieving what the researchers call

8:16 deep detonation within the asteroid's

8:18 interior.

8:19 Anna: The researchers modeled the energy of the

8:21 launch vehicle, the impactor's velocity and

8:24 the resulting change in the asteroid's own

8:26 velocity for both approaches, and then tested

8:29 them against a virtual database of threat

8:31 asteroids, assuming warning times anywhere

8:34 from one year to 20 years.

8:36 Avery: The headline finding if you've got enough

8:38 lead time, the deeper pre excavation

8:41 approach is markedly more efficient at

8:43 actually deflecting the asteroid. But if

8:46 warning time is short, a simple surface

8:48 impact detonation may be the only option

8:50 you've got time to pull off.

8:52 Anna: Worth saying. Clearly there's no known

8:54 asteroid threatening Earth right now.

8:56 Apophis, uh, once flagged as a risk for its

8:59 2029 and 2068 close approaches,

9:02 has been ruled out as a hazard for the

9:04 foreseeable future.

9:05 Avery: But it's not purely theoretical either. Back

9:08 in 2024, a lab experiment published in

9:11 Nature Physics showed that X rays from a

9:14 nuclear blast could genuinely vaporize

9:16 and push an asteroid's surface. And the

9:19 researchers behind that suggested the

9:21 technique could scale up to asteroids as

9:23 large as around 4km across.

9:26 Anna: And it's worth remembering the Chelyabinsk

9:28 meteor back in 2013. A, uh, comparatively

9:31 small object and it still caused real

9:34 property damage and over a thousand injuries.

9:37 Even modest sized asteroids are worth taking

9:40 seriously.

9:40 Avery: Hollywood's favorite plan, nuke it might

9:43 genuinely be a good idea. It's just that.

9:46 Exactly how you nuke it turns out to matter

9:49 enormously.

9:50 Anna: Not quite the Bruce Willis version, but

9:52 planetary defense science is getting a lot

9:55 more precise. And that's exactly what you'd

9:57 want if we ever had to use it for real.

9:59 Alright, time for something a little

10:01 different. Avery, I believe this one's got

10:04 your name on it.

10:05 Avery: It does? Does. Southern hemisphere listeners

10:07 feel free to sit this one out for once

10:09 because this Aurora alert is entirely for

10:12 our friends

10:12 Anna: up north Base weather forecasters are

10:15 watching. Two things line up for July 9th.

10:18 First, a fast coronal mass ejection that

10:21 launched from the sun on July 5th with a

10:23 modeled arrival time around 6 UTC on

10:26 the night.

10:27 Avery: A second, a coronal hole, a patch

10:29 of open magnetic field letting fast solar

10:32 wind escape, is rotating into an Earth

10:35 facing position and its high speed stream is

10:38 expected to arrive around the same time.

10:40 Anna: Put those two together and forecasters say we

10:43 could see G1 class geomagnetic storm

10:45 conditions. Minor on the storm scale, but

10:48 enough to bring the aurora down to some

10:50 surprisingly accessible latitudes.

10:53 Avery: The zones to watch Seattle,

10:55 Edinburgh and the northern tier of the United

10:58 States and Canada.

11:00 Anna: For context, this comes right after last

11:02 week's monster sunspot regions rotated away

11:05 to the sun's far side and they didn't go

11:08 quietly, putting on a real show of flares and

11:11 prominences on their way out.

11:12 Avery: Solar activity's dropped back to low levels

11:15 since then, mostly common C class flares

11:18 with active region

11:19 AR4482. Now the main

11:22 feature we're watching on the Earth facing

11:24 side.

11:24 Anna: So if you're anywhere near Seattle, Edinburgh

11:27 or the northern reaches of the US and Canada,

11:30 July 9 might be where worth stepping outside

11:32 at night and looking up.

11:34 Avery: We don't say that to you nearly often enough.

11:37 Consider this one a, uh, thank you

11:38 Anna: note and we'll close today with a story about

11:40 what comes after the mission of a lifetime.

11:43 Avery: Jeremy Hansen, the Canadian Space Agency

11:46 astronaut who became the first Canadian ever

11:49 to fly around the moon back in April

11:51 aboard Artemis 2, announced on July

11:54 6 that he's stepping back from full time

11:57 astronaut duty.

11:58 Anna: Hansen flew as mission specialist alongside

12:00 NASA astronauts Rosa Reid Wiseman, Victor

12:03 Glover and Christina Koch on the first crewed

12:06 moon mission in over 50 years.

12:08 Avery: The transition takes effect this September

12:10 after 32 years of military service and 17

12:13 years as a CSA astronaut. He'll continue on

12:16 as a reservist with the Royal Canadian Air

12:18 Force and says he remains fully committed to

12:21 Canada's space program, just in a different

12:23 capacity.

12:24 Anna: It's a nice detail that his Artemis 2 mission

12:26 patch incorporated elements of Anishinaabe

12:29 culture, reflecting a vision quest he

12:31 undertook at A.H. turtle Lodge in Sag King

12:33 First Nation during his training.

12:35 Avery: In the months since the mission, he's taken

12:37 on something of a public diplomacy role too.

12:39 Appearances at the White House before

12:41 Congressional committees and at, uh, both

12:43 Canada Day and Independence Day celebrations

12:46 championing the six decades long partnership

12:48 between the US and Canada in space.

12:50 Anna: His departure leaves the CSA with three

12:53 active astronauts in its core, but as Hansen

12:55 tells it, this really isn't a departure at

12:57 all.

12:58 Avery: Weeks after becoming the first Canadian to

13:00 circle the moon and he's already planning his

13:02 next chapter.

13:03 Anna: A good reminder that flying to the moon isn't

13:05 the end of an astronaut's story. Often it's

13:08 just the most famous chapter in it.

13:10 Avery: That's it for today's show. A nuclear

13:12 battery, a fuel free thruster, a plot twist

13:15 5 million kilometers from home, some serious

13:18 planetary defense, an aurora shout out for

13:20 the north, and an astronaut already planning

13:23 what's next.

13:23 Anna: Thanks for spending part of your day with us.

13:25 Find full show notes, sources and links at

13:28 astronomydaily IO and follow us at

13:30 astrodaily Pod for updates between episodes.

13:33 Avery: We'll be back tomorrow with more of the

13:35 universe's news.

13:36 Anna: Until then, Clear Skies

13:40 MHM.

13:49 Avery: Is the

13:50 tongue.