Hacker News new | ask | show | jobs
by eminemence 1742 days ago
What is going to protect this from all those meteoroids,asteroids and cosmic rays?
4 comments

For this approach I don't know. It's a wire mesh so I think it can resist some damage.

I read about other approaches that make me marvel at mankind's genius. For instance, on the moon you could slowly spin a pool of liquid Mercury to obtain a radio telescope that is basically immune from microimpacts. Not sure how it would work once the mercury freezes solid due to lack of sunlight, but I think it's such a beautiful (but maybe impractical) idea :).

You can do that on earth, too. See https://en.wikipedia.org/wiki/NASA_Orbital_Debris_Observator..., https://en.wikipedia.org/wiki/Large_Zenith_Telescope for (decommissioned) examples (both found via https://en.wikipedia.org/wiki/Liquid-mirror_telescope)

The idea apparently came from Isaac Newton.

> Not sure how it would work once the mercury freezes solid due to lack of sunlight, but I think it's such a beautiful (but maybe impractical) idea :).

Can't you heat it through induction heating? Vacuum is good isolation, so it won't lose heat too fast. Keeping whole pool above -30 °C probably won't require too much energy.

Maybe. I honestly don't know and just read about it quite a while ago and can't remember the details.
But mercury is a heavy metal. It must be prohibitively expensive to transfer the amount needed to the moon from earth.
Agreed, that's why I wrote maybe impractical. I just find it fascinating :)
Statistics :) The chance of a wire is hit by something is probably extremely low. Electronics working in space is also an understood problem so I don't think it's an issue.
Probably the proposed wire-mesh design, it won't be a solid reflecting surface. Total exposed surface would be comparable to orbit telescopes.
Cosmic rays are a solved problem. at most you will run out of backup computers. asteroids, you just hope you'll not win the cosmic lottery of collisions.
Like we do on earth with the big ones.

But since there is no atmosphere stopping the small ones on the moon, who also can do damage: this likely will be a problem, because there are a lot of them over time.

So a laser shield might sound science fiction, but will maybe be necessary, for longtime operation?

Or is it possible to build some protective sphere, that does not hinder transmission too much?