July 8, 2026
Nuclear Power in Space, Planetary Defense Insights, and an Aurora Alert for Northern Skies
Astronomy Daily — S05E135 — Wednesday, July 8, 2026 1. World's First Commercial Nuclear-Powered Satellite Reaches Orbit SpaceX's Transporter-17 rideshare mission carried City Labs' BOHR CubeSat to orbit on July 7, the first commercially built satellite to fly a nuclear-powered payload — a tritium betavoltaic cell that generates electricity continuously, day or night, regardless of sunlight. Key points • Launched July 7, 2026 at 3:12am EDT from Vandenberg Space Force Base aboard a Falcon 9, part of the 81-payload Transporter-17 rideshare mission. • BOHR (Betavoltaic Orbital High-Reliability) CubeSat built by City Labs, a Miami/Florida-based company. • Uses a 'NanoTritium' betavoltaic device — converts beta particles from the radioactive decay of tritium directly into electricity via a semiconductor. • Power output is tiny (micro-to-milliwatt range) but continuous — unaffected by eclipse periods or solar panel orientation. • Tritium's 12.3-year half-life means the power source stays effective for two decades before decaying to harmless helium-3. • FAA authorised the launch after finding public radiation exposure would stay below one millirem under conservative assumptions. 2. New Zealand's Fuel-Free Thruster Passes First Orbital Test Auckland-based Zenno Astronautics has successfully tested its 'Supertorquer' — an attitude-control thruster that uses superconducting magnets to push against Earth's own magnetic field, generating thrust with no propellant at all. Key points • Zenno Astronautics is a spin-off from the University of Auckland, New Zealand. • The system, called 'Supertorquer', completed its first in-orbit test in early July 2026. • Superconducting magnets, powered by solar panels, interact with Earth's magnetic field to generate torque and maintain a satellite's orientation — no propellant is consumed. • Until recently this kind of superconducting hardware was too large and complex to fit aboard a small satellite; miniaturisation has now made it practical. • Because it needs no fuel, the technology could in principle keep a satellite maneuvering indefinitely, as long as it has sunlight for power. • Zenno co-founder/company messaging: 'We are essentially looking to remove all reliance on Earth's resources so that we can build a sustainable industry in space.' 3. Tianwen-2 Arrives at Quasi-Moon Kamo'oalewa — And Upends the 'Piece of the Moon' Theory China's Tianwen-2 sample-return spacecraft has arrived at near-Earth asteroid Kamo'oalewa after a 400-day, 1-billion-kilometre journey, beaming back the first close-up image — just as new JWST data throws serious doubt on the leading theory of where this strange little world came from. Key points • Tianwen-2 launched May 29, 2025, and reached Kamo'oalewa on July 6, 2026, arriving at a station-keeping distance of about 20 km. • China National Space Administration (CNSA) publicly announced the arrival July 6, releasing the first close-up image via Xinhua. • Kamo'oalewa (asteroid 2016 HO3) is one of only seven known 'quasi-satellites' of Earth — it orbits the Sun but stays in a stable dance alongside our planet, and has done so for roughly 100 years, with about 300 more to go. • The image reveals a small, asymmetrical rock roughly 20-30 metres across. • Long-standing hypothesis (since 2021): Kamo'oalewa is a fragment blasted off the Moon's far side by the impact that created the Giordano Bruno crater, 1-10 million years ago — based on its reflectance spectrum resembling space-weathered lunar soil. • New twist: a July 1 JWST preprint (Sharkey et al.) models Kamo'oalewa's albedo (reflectivity) at around 0.59 — far higher than the Moon's ~0.12 — which is incompatible with a lunar origin and points instead toward a rare E-type silicate asteroid. 4. Jeremy Hansen Steps Back From Active Astronaut Duty Jeremy Hansen, the Canadian Space Agency astronaut who became the first Canadian to fly around the Moon aboard Artemis II in April, announced July 6 that he's stepping back from full-time astronaut service this September. Key points • Hansen flew as mission specialist on Artemis II in April 2026, alongside NASA astronauts Reid Wiseman, Victor Glover, and Christina Koch — the first crewed lunar mission in over 50 years. • He becomes the first Canadian to travel beyond low Earth orbit / around the Moon. • Announced via social media and a Canadian Space Agency statement on July 6, 2026. • Transition takes effect this September, after 32 years of military service and 17 years as a CSA astronaut. • He will continue serving as a reservist with the Royal Canadian Air Force and says he remains committed to Canada's space program in a new capacity. • Joined CSA in the 2009 astronaut recruitment campaign after a career as a Royal Canadian Air Force fighter pilot. 5. Aurora Alert: G1 Geomagnetic Storm Possible July 9 Space weather forecasters are watching a combination of a fast coronal mass ejection and an Earth-facing coronal hole that could combine to produce a minor (G1-class) geomagnetic storm on July 9 — with aurora potentially visible across the northern United States, Canada, and parts of northern Europe. Key points • A fast CME launched from the Sun on July 5 has a modelled arrival time around 6 UTC on July 9. • Separately, a coronal hole — a region of open magnetic field letting fast solar wind escape — is rotating into an Earth-facing position and its high-speed stream is expected to arrive around the same time. • Combined, NOAA/space weather forecasters say these two effects could produce G1 (minor) geomagnetic storm conditions. • Possible aurora visibility zones: Seattle, Edinburgh, and the northern tier of the United States and Canada. • Context: last week's monster sunspot active regions have now rotated to the Sun's far side after putting on a dramatic show of flares and prominences as they departed. • Solar activity has otherwise dropped to low levels — mostly common C-class flares — with active region AR4482 now the main feature on the Earth-facing side of the Sun. 6. Chinese Researchers Model the Best Way to 'Nuke' a Killer Asteroid A new peer-reviewed study models two different ways a nuclear device could be used to deflect a threatening asteroid — a straightforward surface impact detonation, or a 'pre-excavation' approach that digs a crater first before delivering a deeper, more effective blast — and finds the right choice depends heavily on how much warning time we have. Key points • Published July 7, 2026 in the journal Space: Science & Technology. • Compares two nuclear deflection modes: (1) 'impact detonation' — a simple, shallow-crater surface blast, and (2) 'pre-excavation detonation' — using a penetrator device to dig a deeper crater first, then detonating a warhead to achieve 'deep detonation' inside the asteroid. • Researchers modelled launch vehicle energy, impactor spacecraft velocity, and the resulting change in the asteroid's velocity for both modes. • Both modes were tested against a 'virtual threat asteroid database' assuming warning times ranging from one year to twenty years. • Headline finding: given enough warning time, the deeper 'pre-excavation' detonation is markedly more efficient at deflecting an asteroid than a simple surface blast — but a straightforward impact detonation may still be the only option when warning time is short. • Context: no known asteroid currently poses an imminent threat to Earth — Apophis, once considered a risk for its 2029 and 2068 close approaches, has been ruled out as a hazard for the foreseeable future.
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WEBVTT
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Anna: From nuclear powered satellites to a, uh,
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thruster that never runs out of fuel. This is
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Astronomy Daily.
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Avery: I'm Avery.
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Anna: And I'm anna. It's Wednesday, July 8,
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2026, and this is season five, episode
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135.
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Avery: Big show today, Anna. We've got a genuine
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technology first, a Kiwi engineering trick
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that sounds almost too clever to be true. A
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plot twist five years in the making, and for
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once, a story that isn't about our Southern
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Hemisphere listeners.
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Anna: That's right. Today we're tipping our hat to
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the northern half of our audience, who make
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up the bulk of our listeners, but don't
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always get a sky story written just for them.
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Avery: Plus, a serious look at planetary defense.
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And we close things out with an astronaut
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who's already planning his next chapter just
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weeks after circling the moon.
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Anna: Let's get into it, and let's start with a,
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uh, genuine first.
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On July 7, SpaceX's Transporter
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17 rideshare mission lifted off from
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Vandenberg Space force base, carrying 81
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payloads. And tucked along them was something
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that's never flown before on a commercial
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mission.
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Avery: This is the Bore cubesat, built by a Florida
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company called City Labs. And what makes it
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special is what's powering one of its
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payloads. A tiny nuclear battery.
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Anna: Now, before anyone pictures a miniature
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reactor. This is something much gentler.
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It's called a beta voltaic device. City
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Labs calls the technology nanotritium.
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It takes the beta particles thrown off as
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tritium decays and converts them directly
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into electricity through a semiconductor.
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Avery: The power output is tiny. We're talking micro
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to milliwatts. Not enough to run your kettle.
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But here's the trick. It's continuous day or
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night, in sunlight or in shadow. It just
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keeps producing power.
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Anna: And tritium has a half life of 12.3
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years. So this thing stays effective for 20
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years before it quietly decays into harmless
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helium 3.
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Avery: The FAA had to sign off on this one, too.
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They concluded that public radiation exposure
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from the mission would stay under 1 millirem
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using conservative assumptions. So this has
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been vetted from a safety standpoint, not
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just an Engineering 1.
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Anna: Citilab CEO Peter Kabawi called it a
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historic step for commercial nuclear power in
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space and said it enables, quote,
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persistent always on payload operations
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that are not constrained by sunlight or
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battery life.
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Avery: Worth being? Clear. This isn't like the
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plutonium rtgs powering Voyager or
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New Horizons or the Mars rovers, which
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generate power from heat. This is much
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smaller, much lower power. And it's still
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relying on solar panels for its main Systems.
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This is a proof of concept, but
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Anna: it's a proof of concept with a very specific
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use case in mind. Permanently shadowed
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craters on the moon, for instance, where the
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sun genuinely never reaches. NASA's
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floated tritium beta voltaics as a way to run
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small autonomous sensors in exactly those
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conditions.
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Avery: Solar panels have run space missions for
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seven decades. This is the first real
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commercial attempt at an answer to the
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question, what happens when the sun doesn't
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reach you at all?
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Anna: It's a small battery, but if it scales, it
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opens some very dark corners of the solar
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system.
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Avery: Sticking with clever engineering, this next
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one comes from a lot closer to home for you,
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Anna.
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Anna: It does. This is a New Zealand story. A
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company called Zeno Astronautics, a spinoff
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from the University of Auckland, has just
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completed the first orbital test of something
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called the Super Torquer.
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Avery: And the pitch here is genuinely wild. It's a
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thruster that never runs out of fuel because
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it doesn't use any fuel at all.
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Anna: Here's how it works. The Super Torquer uses
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superconducting magnets powered by the
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satellite's solar panels. And those magnets
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push against Earth's own magnetic field.
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That interaction generates torque enough to
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turn and orient the satellite with zero
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propellant consumed.
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Avery: Superconducting magnets have been on people's
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wish list for this kind of job for years. But
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the hardware was always too big and too
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complicated to fit on a small satellite.
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Miniaturization has finally caught up with
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the
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Anna: idea to be precise about what this replaces.
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It's primarily for attitude control, so
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turning and orientation rather than big
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or get changing maneuvers. It's, uh, a much
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cleaner alternative to the cold gas thrusters
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satellites currently use just to point
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themselves the right way.
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Avery: But if you never need propellant for that
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job, a, uh, satellite's operational lifetime
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stops being limited by how much gas it
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launched with.
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Anna: Dano's own messaging captures the
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ambition nicely. They say they're trying to,
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quote, remove all reliance on
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Earth's resources so that we can build a
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sustainable industry in space. No
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tanks, no valves, nothing to run dry.
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Just magnets, sunlight and the planet's own
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magnetic field doing the work. A very
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kiwi way to solve a very old space
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problem.
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Now to an ongoing story that just took a
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genuine twist. Longtime listeners will
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remember we've been tracking China's Tianwen
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2 mission on its approach to the near Earth
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asteroid Kamaua Lewa.
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Avery: Well, on July 6th, after a 400 day,
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roughly 1 billion kilometer journey,
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Tianwen 2 arrived, settling in at a
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station keeping distance of about 20 km from
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the surface. China's space agency released
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the first close up image the same day.
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Anna: For context on what Kamalalewa actually is,
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it's one of only seven known quasi
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satellites of Earth. It orbits the sun, but
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it stays locked in a stable dance alongside
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our planet and has done so for roughly a
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hundred years, with about 300 more to
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go.
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Avery: The image shows a small asymmetrical rock
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somewhere in the range of 20 to 30 meters
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across. Tiny as these things go.
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Anna: Now, here's where it gets interesting. Since
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2021, the leading theory has been that Kamau
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Lewa is, uh, a genuine chip off our own moon,
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blasted off the lunar far side by the impact
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that created the Giordano Bruno crater
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somewhere between 1 and 10 million years ago.
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That was based on its reflectance spectrum,
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looking a lot like space weathered lunar
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soil.
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Avery: But just five days before Tianwen 2
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arrived, a JWST preprint
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modeled Kamawa Lea's albedo. How
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reflective it is. At 0.59,
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the moon's albedo is only about
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0.12. That's a huge
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mismatch and it's simply not compatible with
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a lunar origin.
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Anna: Astronomer Mikhail Grandvik of the University
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of Helsinki says the new TN12
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image basically confirms the albedo
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result from the JWST data,
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pointing instead toward Kamaualewa being a
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rare type of silicate asteroid
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entirely unrelated to our Moon.
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Avery: For five years, the story was it's a piece of
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the moon. That story might not survive
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contact with
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Anna: the evidence, which is exactly why Tianwen
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2 is there. Over the next year, it'll study
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kamauu Lewa with 11 science instruments
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before attempting to collect somewhere
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between 20 and 100 milligrams of surface
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material using whichever of three sampling
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techniques suits the asteroid surface best.
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Avery: Sample return is planned via an earth flyby
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around April 2027. And only then
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will we really know for certain what this
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little rock is made of.
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Anna: The only way to settle it for good is to
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bring a piece of it home.
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Now staying with asteroids, but shifting from
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origins to defense, because a new study
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out this week tackles a question that sounds
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like it's straight out of a disaster movie.
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Avery: How exactly do you nuke an asteroid if it
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ever comes to that? A peer reviewed paper
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published July 7 in the journal
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Science and Technology models two different
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approaches to nuclear asteroid deflection.
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Anna: Model one is what you'd probably
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an impact detonation. You hit the
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surface, create a shallow crater and
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detonate a nuclear Device there.
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Avery: Mode 2 is more elaborate. A, uh, pre
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excavation Detonation, A penetrator
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device digs a deeper crater first and
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then the warhead goes off inside that
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crater, achieving what the researchers call
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deep detonation within the asteroid's
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interior.
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Anna: The researchers modeled the energy of the
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launch vehicle, the impactor's velocity and
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the resulting change in the asteroid's own
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velocity for both approaches, and then tested
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them against a virtual database of threat
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asteroids, assuming warning times anywhere
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from one year to 20 years.
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Avery: The headline finding if you've got enough
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lead time, the deeper pre excavation
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approach is markedly more efficient at
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actually deflecting the asteroid. But if
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warning time is short, a simple surface
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impact detonation may be the only option
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you've got time to pull off.
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Anna: Worth saying. Clearly there's no known
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asteroid threatening Earth right now.
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Apophis, uh, once flagged as a risk for its
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2029 and 2068 close approaches,
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has been ruled out as a hazard for the
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foreseeable future.
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Avery: But it's not purely theoretical either. Back
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in 2024, a lab experiment published in
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Nature Physics showed that X rays from a
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nuclear blast could genuinely vaporize
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and push an asteroid's surface. And the
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researchers behind that suggested the
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technique could scale up to asteroids as
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large as around 4km across.
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Anna: And it's worth remembering the Chelyabinsk
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meteor back in 2013. A, uh, comparatively
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small object and it still caused real
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property damage and over a thousand injuries.
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Even modest sized asteroids are worth taking
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seriously.
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Avery: Hollywood's favorite plan, nuke it might
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genuinely be a good idea. It's just that.
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Exactly how you nuke it turns out to matter
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enormously.
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Anna: Not quite the Bruce Willis version, but
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planetary defense science is getting a lot
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more precise. And that's exactly what you'd
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want if we ever had to use it for real.
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Alright, time for something a little
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different. Avery, I believe this one's got
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your name on it.
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Avery: It does? Does. Southern hemisphere listeners
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feel free to sit this one out for once
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because this Aurora alert is entirely for
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our friends
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Anna: up north Base weather forecasters are
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watching. Two things line up for July 9th.
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First, a fast coronal mass ejection that
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launched from the sun on July 5th with a
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modeled arrival time around 6 UTC on
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the night.
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Avery: A second, a coronal hole, a patch
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of open magnetic field letting fast solar
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wind escape, is rotating into an Earth
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facing position and its high speed stream is
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expected to arrive around the same time.
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Anna: Put those two together and forecasters say we
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could see G1 class geomagnetic storm
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conditions. Minor on the storm scale, but
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enough to bring the aurora down to some
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surprisingly accessible latitudes.
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Avery: The zones to watch Seattle,
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Edinburgh and the northern tier of the United
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States and Canada.
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Anna: For context, this comes right after last
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week's monster sunspot regions rotated away
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to the sun's far side and they didn't go
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quietly, putting on a real show of flares and
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prominences on their way out.
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Avery: Solar activity's dropped back to low levels
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since then, mostly common C class flares
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with active region
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AR4482. Now the main
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feature we're watching on the Earth facing
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side.
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Anna: So if you're anywhere near Seattle, Edinburgh
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or the northern reaches of the US and Canada,
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July 9 might be where worth stepping outside
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at night and looking up.
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Avery: We don't say that to you nearly often enough.
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Consider this one a, uh, thank you
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Anna: note and we'll close today with a story about
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what comes after the mission of a lifetime.
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Avery: Jeremy Hansen, the Canadian Space Agency
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astronaut who became the first Canadian ever
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to fly around the moon back in April
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aboard Artemis 2, announced on July
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6 that he's stepping back from full time
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astronaut duty.
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Anna: Hansen flew as mission specialist alongside
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NASA astronauts Rosa Reid Wiseman, Victor
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Glover and Christina Koch on the first crewed
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moon mission in over 50 years.
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Avery: The transition takes effect this September
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after 32 years of military service and 17
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years as a CSA astronaut. He'll continue on
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as a reservist with the Royal Canadian Air
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Force and says he remains fully committed to
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Canada's space program, just in a different
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capacity.
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Anna: It's a nice detail that his Artemis 2 mission
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patch incorporated elements of Anishinaabe
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culture, reflecting a vision quest he
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undertook at A.H. turtle Lodge in Sag King
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First Nation during his training.
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Avery: In the months since the mission, he's taken
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on something of a public diplomacy role too.
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Appearances at the White House before
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Congressional committees and at, uh, both
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Canada Day and Independence Day celebrations
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championing the six decades long partnership
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between the US and Canada in space.
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Anna: His departure leaves the CSA with three
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active astronauts in its core, but as Hansen
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tells it, this really isn't a departure at
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all.
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Avery: Weeks after becoming the first Canadian to
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circle the moon and he's already planning his
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next chapter.
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Anna: A good reminder that flying to the moon isn't
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the end of an astronaut's story. Often it's
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just the most famous chapter in it.
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Avery: That's it for today's show. A nuclear
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battery, a fuel free thruster, a plot twist
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5 million kilometers from home, some serious
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planetary defense, an aurora shout out for
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the north, and an astronaut already planning
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what's next.
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Anna: Thanks for spending part of your day with us.
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Find full show notes, sources and links at
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astronomydaily IO and follow us at
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astrodaily Pod for updates between episodes.
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Avery: We'll be back tomorrow with more of the
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universe's news.
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Anna: Until then, Clear Skies
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MHM.
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Avery: Is the
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tongue.
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Anna: From nuclear powered satellites to a, uh,
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thruster that never runs out of fuel. This is
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Astronomy Daily.
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Avery: I'm Avery.
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Anna: And I'm anna. It's Wednesday, July 8,
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2026, and this is season five, episode
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135.
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Avery: Big show today, Anna. We've got a genuine
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technology first, a Kiwi engineering trick
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that sounds almost too clever to be true. A
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plot twist five years in the making, and for
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once, a story that isn't about our Southern
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Hemisphere listeners.
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Anna: That's right. Today we're tipping our hat to
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the northern half of our audience, who make
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up the bulk of our listeners, but don't
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always get a sky story written just for them.
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Avery: Plus, a serious look at planetary defense.
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And we close things out with an astronaut
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who's already planning his next chapter just
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weeks after circling the moon.
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Anna: Let's get into it, and let's start with a,
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uh, genuine first.
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On July 7, SpaceX's Transporter
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17 rideshare mission lifted off from
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Vandenberg Space force base, carrying 81
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payloads. And tucked along them was something
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that's never flown before on a commercial
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mission.
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Avery: This is the Bore cubesat, built by a Florida
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company called City Labs. And what makes it
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special is what's powering one of its
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payloads. A tiny nuclear battery.
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Anna: Now, before anyone pictures a miniature
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reactor. This is something much gentler.
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It's called a beta voltaic device. City
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Labs calls the technology nanotritium.
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It takes the beta particles thrown off as
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tritium decays and converts them directly
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into electricity through a semiconductor.
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Avery: The power output is tiny. We're talking micro
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to milliwatts. Not enough to run your kettle.
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But here's the trick. It's continuous day or
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night, in sunlight or in shadow. It just
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keeps producing power.
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Anna: And tritium has a half life of 12.3
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years. So this thing stays effective for 20
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years before it quietly decays into harmless
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helium 3.
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Avery: The FAA had to sign off on this one, too.
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They concluded that public radiation exposure
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from the mission would stay under 1 millirem
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using conservative assumptions. So this has
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been vetted from a safety standpoint, not
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just an Engineering 1.
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Anna: Citilab CEO Peter Kabawi called it a
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historic step for commercial nuclear power in
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space and said it enables, quote,
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persistent always on payload operations
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that are not constrained by sunlight or
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battery life.
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Avery: Worth being? Clear. This isn't like the
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plutonium rtgs powering Voyager or
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New Horizons or the Mars rovers, which
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generate power from heat. This is much
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smaller, much lower power. And it's still
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relying on solar panels for its main Systems.
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This is a proof of concept, but
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Anna: it's a proof of concept with a very specific
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use case in mind. Permanently shadowed
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craters on the moon, for instance, where the
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sun genuinely never reaches. NASA's
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floated tritium beta voltaics as a way to run
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small autonomous sensors in exactly those
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conditions.
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Avery: Solar panels have run space missions for
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seven decades. This is the first real
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commercial attempt at an answer to the
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question, what happens when the sun doesn't
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reach you at all?
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Anna: It's a small battery, but if it scales, it
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opens some very dark corners of the solar
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system.
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Avery: Sticking with clever engineering, this next
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one comes from a lot closer to home for you,
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Anna.
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Anna: It does. This is a New Zealand story. A
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company called Zeno Astronautics, a spinoff
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from the University of Auckland, has just
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completed the first orbital test of something
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called the Super Torquer.
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Avery: And the pitch here is genuinely wild. It's a
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thruster that never runs out of fuel because
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it doesn't use any fuel at all.
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Anna: Here's how it works. The Super Torquer uses
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superconducting magnets powered by the
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satellite's solar panels. And those magnets
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push against Earth's own magnetic field.
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That interaction generates torque enough to
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turn and orient the satellite with zero
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propellant consumed.
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Avery: Superconducting magnets have been on people's
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wish list for this kind of job for years. But
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the hardware was always too big and too
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complicated to fit on a small satellite.
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Miniaturization has finally caught up with
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the
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Anna: idea to be precise about what this replaces.
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It's primarily for attitude control, so
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turning and orientation rather than big
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or get changing maneuvers. It's, uh, a much
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cleaner alternative to the cold gas thrusters
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satellites currently use just to point
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themselves the right way.
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Avery: But if you never need propellant for that
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job, a, uh, satellite's operational lifetime
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stops being limited by how much gas it
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launched with.
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Anna: Dano's own messaging captures the
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ambition nicely. They say they're trying to,
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quote, remove all reliance on
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Earth's resources so that we can build a
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sustainable industry in space. No
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tanks, no valves, nothing to run dry.
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Just magnets, sunlight and the planet's own
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magnetic field doing the work. A very
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kiwi way to solve a very old space
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problem.
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Now to an ongoing story that just took a
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genuine twist. Longtime listeners will
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remember we've been tracking China's Tianwen
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2 mission on its approach to the near Earth
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asteroid Kamaua Lewa.
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Avery: Well, on July 6th, after a 400 day,
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roughly 1 billion kilometer journey,
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Tianwen 2 arrived, settling in at a
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station keeping distance of about 20 km from
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the surface. China's space agency released
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the first close up image the same day.
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Anna: For context on what Kamalalewa actually is,
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it's one of only seven known quasi
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satellites of Earth. It orbits the sun, but
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it stays locked in a stable dance alongside
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our planet and has done so for roughly a
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hundred years, with about 300 more to
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go.
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Avery: The image shows a small asymmetrical rock
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somewhere in the range of 20 to 30 meters
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across. Tiny as these things go.
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Anna: Now, here's where it gets interesting. Since
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2021, the leading theory has been that Kamau
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Lewa is, uh, a genuine chip off our own moon,
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blasted off the lunar far side by the impact
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that created the Giordano Bruno crater
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somewhere between 1 and 10 million years ago.
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That was based on its reflectance spectrum,
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looking a lot like space weathered lunar
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soil.
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Avery: But just five days before Tianwen 2
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arrived, a JWST preprint
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modeled Kamawa Lea's albedo. How
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reflective it is. At 0.59,
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the moon's albedo is only about
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0.12. That's a huge
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mismatch and it's simply not compatible with
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a lunar origin.
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Anna: Astronomer Mikhail Grandvik of the University
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of Helsinki says the new TN12
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image basically confirms the albedo
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result from the JWST data,
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pointing instead toward Kamaualewa being a
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rare type of silicate asteroid
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entirely unrelated to our Moon.
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Avery: For five years, the story was it's a piece of
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the moon. That story might not survive
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contact with
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Anna: the evidence, which is exactly why Tianwen
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2 is there. Over the next year, it'll study
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kamauu Lewa with 11 science instruments
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before attempting to collect somewhere
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between 20 and 100 milligrams of surface
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material using whichever of three sampling
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techniques suits the asteroid surface best.
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Avery: Sample return is planned via an earth flyby
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around April 2027. And only then
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will we really know for certain what this
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little rock is made of.
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Anna: The only way to settle it for good is to
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bring a piece of it home.
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Now staying with asteroids, but shifting from
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origins to defense, because a new study
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out this week tackles a question that sounds
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like it's straight out of a disaster movie.
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Avery: How exactly do you nuke an asteroid if it
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ever comes to that? A peer reviewed paper
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published July 7 in the journal
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Science and Technology models two different
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approaches to nuclear asteroid deflection.
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Anna: Model one is what you'd probably
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an impact detonation. You hit the
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surface, create a shallow crater and
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detonate a nuclear Device there.
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Avery: Mode 2 is more elaborate. A, uh, pre
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excavation Detonation, A penetrator
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device digs a deeper crater first and
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then the warhead goes off inside that
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crater, achieving what the researchers call
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deep detonation within the asteroid's
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interior.
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Anna: The researchers modeled the energy of the
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launch vehicle, the impactor's velocity and
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the resulting change in the asteroid's own
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velocity for both approaches, and then tested
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them against a virtual database of threat
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asteroids, assuming warning times anywhere
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from one year to 20 years.
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Avery: The headline finding if you've got enough
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lead time, the deeper pre excavation
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approach is markedly more efficient at
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actually deflecting the asteroid. But if
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warning time is short, a simple surface
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impact detonation may be the only option
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you've got time to pull off.
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Anna: Worth saying. Clearly there's no known
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asteroid threatening Earth right now.
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Apophis, uh, once flagged as a risk for its
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2029 and 2068 close approaches,
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has been ruled out as a hazard for the
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foreseeable future.
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Avery: But it's not purely theoretical either. Back
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in 2024, a lab experiment published in
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Nature Physics showed that X rays from a
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nuclear blast could genuinely vaporize
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and push an asteroid's surface. And the
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researchers behind that suggested the
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technique could scale up to asteroids as
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large as around 4km across.
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Anna: And it's worth remembering the Chelyabinsk
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meteor back in 2013. A, uh, comparatively
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small object and it still caused real
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property damage and over a thousand injuries.
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Even modest sized asteroids are worth taking
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seriously.
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Avery: Hollywood's favorite plan, nuke it might
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genuinely be a good idea. It's just that.
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Exactly how you nuke it turns out to matter
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enormously.
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Anna: Not quite the Bruce Willis version, but
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planetary defense science is getting a lot
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more precise. And that's exactly what you'd
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want if we ever had to use it for real.
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Alright, time for something a little
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different. Avery, I believe this one's got
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your name on it.
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Avery: It does? Does. Southern hemisphere listeners
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feel free to sit this one out for once
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because this Aurora alert is entirely for
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our friends
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Anna: up north Base weather forecasters are
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watching. Two things line up for July 9th.
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First, a fast coronal mass ejection that
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launched from the sun on July 5th with a
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modeled arrival time around 6 UTC on
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the night.
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Avery: A second, a coronal hole, a patch
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of open magnetic field letting fast solar
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wind escape, is rotating into an Earth
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facing position and its high speed stream is
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expected to arrive around the same time.
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Anna: Put those two together and forecasters say we
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could see G1 class geomagnetic storm
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conditions. Minor on the storm scale, but
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enough to bring the aurora down to some
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surprisingly accessible latitudes.
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Avery: The zones to watch Seattle,
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Edinburgh and the northern tier of the United
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States and Canada.
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Anna: For context, this comes right after last
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week's monster sunspot regions rotated away
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to the sun's far side and they didn't go
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quietly, putting on a real show of flares and
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prominences on their way out.
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Avery: Solar activity's dropped back to low levels
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since then, mostly common C class flares
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with active region
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AR4482. Now the main
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feature we're watching on the Earth facing
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side.
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Anna: So if you're anywhere near Seattle, Edinburgh
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or the northern reaches of the US and Canada,
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July 9 might be where worth stepping outside
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at night and looking up.
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Avery: We don't say that to you nearly often enough.
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Consider this one a, uh, thank you
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Anna: note and we'll close today with a story about
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what comes after the mission of a lifetime.
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Avery: Jeremy Hansen, the Canadian Space Agency
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astronaut who became the first Canadian ever
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to fly around the moon back in April
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aboard Artemis 2, announced on July
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6 that he's stepping back from full time
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astronaut duty.
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Anna: Hansen flew as mission specialist alongside
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NASA astronauts Rosa Reid Wiseman, Victor
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Glover and Christina Koch on the first crewed
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moon mission in over 50 years.
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Avery: The transition takes effect this September
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after 32 years of military service and 17
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years as a CSA astronaut. He'll continue on
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as a reservist with the Royal Canadian Air
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Force and says he remains fully committed to
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Canada's space program, just in a different
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capacity.
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Anna: It's a nice detail that his Artemis 2 mission
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patch incorporated elements of Anishinaabe
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culture, reflecting a vision quest he
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undertook at A.H. turtle Lodge in Sag King
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First Nation during his training.
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Avery: In the months since the mission, he's taken
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on something of a public diplomacy role too.
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Appearances at the White House before
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Congressional committees and at, uh, both
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Canada Day and Independence Day celebrations
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championing the six decades long partnership
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between the US and Canada in space.
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Anna: His departure leaves the CSA with three
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active astronauts in its core, but as Hansen
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tells it, this really isn't a departure at
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all.
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Avery: Weeks after becoming the first Canadian to
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circle the moon and he's already planning his
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next chapter.
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Anna: A good reminder that flying to the moon isn't
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the end of an astronaut's story. Often it's
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just the most famous chapter in it.
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Avery: That's it for today's show. A nuclear
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battery, a fuel free thruster, a plot twist
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5 million kilometers from home, some serious
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planetary defense, an aurora shout out for
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the north, and an astronaut already planning
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what's next.
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Anna: Thanks for spending part of your day with us.
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Find full show notes, sources and links at
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astronomydaily IO and follow us at
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astrodaily Pod for updates between episodes.
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Avery: We'll be back tomorrow with more of the
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universe's news.
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Anna: Until then, Clear Skies
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MHM.
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Avery: Is the
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tongue.
