BAN #369: Spooky live interview, Protoplanet landslide

Subscribers turn around and see their reflection in the briny sodium carbonate infused snow covered hills 

Upcoming Appearances/Shameless Self-Promotion

Where I’ll be doing things you can watch and listen to or read about

On this Thursday — October 28 at 21:30 UTC (17:30 Eastern US time) — I will be doing a live video interview with my old friend and SETI astronomer Seth Shostak for a program they’re calling “A Nightmare on SETI Street”. It’s Halloween season so of course we’ll be talking about all the fun ways the Universe can melt your face off.

It will be LIVE on Twitch.tv, Twitter, and YouTube. In fact to make it easier I’ll embed the YouTube stream here so you can find it easily:

Seth is a bona fide alien hunter* (in the real sense of looking for their signals coming from space if an intelligent species out there is broadcasting) and we’ve known each so long I’m not really sure when and where we first met. He’s a riot so this should be fun, if talking about magnetars and black holes and nearby supernovae and gamma-ray bursts cooking the planet is your definition of “fun”. It kinda is for me.

P.S. If you give a donation to the SETI Institute, they’ll send you a free ebook called “10 Spookiest Places in the Universe”.

* It’s cracking me up that I decided to find a page to link to him and figured Wikipedia would do, and the photo they have for him is from a panel I was on called “Death from the Skies!” based on my book.

Blog Jam

What I’ve recently written on the blog, ICYMI

Monday 18 October, 2021: Mercury's atmosphere thickened as we watched. The likely perp? Meteoroids.

Tuesday 19 October, 2021: A single object ripped out over 1,600 Fast Radio Bursts in just a few days and no one knows why

Wednesday 20 October, 2021: Cancel Columbus Day: Sun storms pinpoint Europeans being in Canada in 1021 A.D.

Thursday 21 October, 2021: Astronomers 'find' a second planet orbiting Beta Pictoris due to extremely tiny wiggles by the first planet

Friday 22 October, 2021: The case of the Centaurs that didn't bark in the night

Astro Tidbit

A brief synopsis of some interesting astronomy/science news

Every now and then I read a paper that is not necessarily mind-blowing, but still cool in some way. For example, by coincidence, I happened to find two different papers about counting boulders on other bodies to understand what’s going on on their surfaces; in that case it was the planet Mercury and the protoplanet Ceres, and I wrote about them on the blog.

And then, just a month or so later, another paper comes out looking at landslides on Ceres! It dovetails pretty well with the paper I wrote about on the blog for Ceres: In the first paper, they looked at boulders on its surface and determined they were more fragile than boulders on Vesta (another protoplanet; both Vesta and Ceres are the two largest objects in the Main Asteroid Belt between Mars and Jupiter). We know the surface of Ceres is icier than Vesta’s, because several craters on Ceres have bright salts in them, indicating water bubbling up from below in events called cryovolcanism (volcanoes, but cold). Also, there’s this bizarre mountain on Ceres called Ahuna Mons which is likely a cryovolcano.

The second paper about landslides winds up coming to the same conclusion about Ceres. They found landslides of fine-grained material, indicating that the surface is more porous than you’d expect. If so, then the porosity of the surface gives it more opportunity to store volatiles there, substances like water ice that can turn to gas and go away (going directly from solid to gas in a process called sublimation).

So the porous nature of the surface helps it retain volatiles, and that also makes the rocks on the surface more fragile. Neat!

It would be interesting to walk on Ceres. The surface gravity is 1/40th Earth’s, so you’d only weigh a few pounds, but if the material there is that fragile it might still crunch underfoot like really cold snow. Sometimes here in winter in Colorado the snow squeaks when you walk on it, and it’s pretty funny (and fun). I guess that depends on the crystal shape of the ice. Would the same be true on Ceres, or small asteroids like Bennu and Ryugu?

Maybe someday someone will find out.

Et alia

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