Supernova Hazards and Cloudy With a Chance of Sand

·40 min·4 clips

Would you choose a daytime comet, a supernova brighter than Venus, or a giant lunar impact you could see from Earth?

The episode opens with the hosts—Josh Caldwell, Audrey Martin, Jim Cooney, and Tracy Becker—debating a 'stumper' question about which rare celestial event they'd choose to see: a daytime comet, a supernova visible in daylight, or a massive lunar impact. Jim argues for the supernova, Audrey prefers the lunar impact for its instant spectacle, and Josh chooses the comet for its public engagement potential. The conversation shifts to Jim's 'hot take' that humans might be the only sentient species in the observable universe, which Tracy and Audrey counter with statistical arguments about the likelihood of other life. The main topic begins with a discussion of supernova types, referencing a sponsor segment that humorously advertises type two supernovas for heavy element production. They delve into a new study by Robert Brakenridge that examines how nearby supernovas within the last 50,000 years have affected Earth's environment, using ice core and tree ring data to link these events to atmospheric changes and minor extinction events. The hosts note that Betelgeuse, at 700 light-years away, might not pose a significant threat. Tracy offers an optimistic counterpoint that supernova radiation could potentially trigger life-forming chemistry on other worlds. The episode includes space news updates: SpaceX's Starlink now has 7,600 satellites, Amazon's Kuiper network is launching more satellites, and Blue Origin's lunar landing plans face delays. A trivia segment introduces the 'foe' unit of energy (10^44 joules), equal to a supernova's output or the Sun's lifetime energy. The second main topic covers JWST observations of a young planetary system where sand (silicate) clouds are detected in circumstellar disks and are cycling through the atmospheres of giant exoplanets. The hosts discuss particle sizes, health implications of silicate inhalation, and comparisons to our solar system's formation. The episode concludes with the trivia answer reveal and closing remarks.

As heard by us

A lunar fuel plan and nearby-supernova risk share the stage with a lunch-minded detour on energy units.

Walk About the Galaxy pairs lunar logistics with the more unnerving question of what a nearby supernova might mean for Earth. The Astroquarks look at a proposed vehicle for moving materials and fuel from low-Earth orbit to lunar orbit for use by lunar landers, then set a stated…

Read the full review in PlayNext →

Why you'd press play

You get nearby-supernova danger with a side trip through lunar logistics, and the panel somehow turns an astronomy energy unit into lunch.

Read the full recommendation in PlayNext →

Listen to the show on

Apple Podcasts Spotify

Play clips from this episode More from Walkabout the Galaxy