Steampunk_Prof8h ago
Prof. Sam Lawler

RE: https://fosstodon.org/@AkaSci/116359971598652059

Spent all day driving through gorgeous mountains towards home, now trying to catch up on Artemis stuff so I can talk about it at stupid-o-clock in the morning on live Saskatchewan radio tomorrow morning (I'm baaack. Apparently).

Thanks to @AkaSci for a great summary of the closest approach!

The absolutely coolest detail (to me): the astronauts could SEE flashes from meteors hitting the surface?!! From 4,000km away?! (And they want to build a moon base???) Lots to think about, wow.

4:58amWeb
Show threadRoy -- the dull one13h ago

@sundogplanets @AkaSci

Don't worry about those meteors. Between "The Singularity" and the Glory of AGI and the Ecstasy of Ketamine, we are invincible!

Well, not you and me, it's the dingalings who are invincible. 🥴

Show threadHoward Chu @ Symas13h ago
@sundogplanets @AkaSci yeah, when a body's surface is so completely covered with impact craters it does make you wonder about the wisdom of trying to build anything there. But I guess, if you can date the craters' ages and the average is thousands to millions of years old, maybe the odds are in your favor?
Show threadJoe ❌👑13h ago
@sundogplanets @AkaSci I wonder what the statistics are, how long you'd need to expect to wait before your base site getting a significant meteor strike. If it's a hundred years or more, I guess that's not that different from living on an earthquake fault in California.
Show threadTimo13h ago
@not2b @sundogplanets @AkaSci perhaps the base could have a ballroom design with a drone proof roof? That should stop the meteors, right? <sarcasm>
Show threadMichael Busch12h ago

@sundogplanets

I would like to see the recordings of those flashes.

Because the cameras will tell between actual impact flashes and phosphenes from cosmic ray hits.

Show threadProf. Sam Lawler5h ago
@michael_w_busch ohhhhh WEIRD I didn't even think about that!!
Show threadAmin, minor deity of the legume realm5h ago

@michael_w_busch @sundogplanets

Oh, wow, excellent point.

Show threadMichael Busch5h ago

@amin @sundogplanets

Nearly all astronauts report seeing phosphenes in the dark when they are not paying attention to something else: https://pubmed.ncbi.nlm.nih.gov/16676658/ .

But any given cosmic ray will hit just one camera or eyeball, while actual flashes will show up in everything looking in the right direction.

Phosphenes in low earth orbit: survey responses from 59 astronauts - PubMed

Comparisons with earlier studies of light flashes in space and several ground-based studies during the 1970s are made. One interesting observation from this is that it seems that a small fraction of the light flashes is caused by Cherenkov radiation, while the majority is probably caused by some kin …

PubMed
Show threadAmin, minor deity of the legume realm4h ago

@michael_w_busch @sundogplanets

Sure! I wonder, though, if phosphenes might be differentiable from what they're describing. I presume the impacts would appear to be on the surface of the moon, while I would imagine phosphenes to look more obviously like something occluding the vision? Having not experienced them, of course, I have no idea. :)

Show threadMichael Busch4h ago

@amin @sundogplanets

Phosphenes from particle hits in the eyeball look like brief white streaks; rather than the larger effects that happen from hitting the nerves with electromagnetic interference.

Or so I am told by biophysicists I know who get to play with medical scanners.

Show threadLuke Drury5h ago
@amin @michael_w_busch @sundogplanets If they only saw them on the lunar surface, and not in the surrounding sky, that would support a meteor impact origin, but CR induced flashes in the eye are a known phenomenon.
Show threadSulfide_Sleuth12h ago

@sundogplanets @AkaSci
Wow that is a neat detail with the meteorite flashes! Didn't realize they had actually been seen. Would be cool to use longer observations to determine their flux better.

I would argue tho that the ones we really need to worry about are the more common ones we can't see (micrometeorites). The flux is way higher, and while less catastrophic they would end up wrecking havoc on components.

Think most plans atm rely on underground bases built into the bottom of larger craters. Protects from meteorites, solar winds, and cosmic rays, all while having a potential source of water nearby.

Funny enough tho one of the reasons to build a moon base is exactly because of those hazards. The solar winds are a source of He3 (needed for MRIs) and the Meteorites are actually a great sources of siderophile elements (ie critical metals needed for a whole host of different things). Well at least according to one paper by some crazy guy 😁.
https://doi.org/10.1111/maps.14184

Show threadLaukidh12h ago
@sundogplanets @AkaSci I hope they get a moon, earth, and Venus pic
Show threadMetafísica rococó11h ago
@sundogplanets @AkaSci I don't think there is a solid scientific reason to throw people around the moon or to land them there. Probes can take photos and collect data, even assemble stuff. The cost and risk of maintaining people in the bottom of the sea would be less than in the moon. Maybe this is just some Empire show-off or something