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Comment by conqueso | Hacker News Reader

I'm curious about the nature of the damage. article mentions that the affected mirror will be adjusted to minimize the distortion that was introduced, so obviously not a crack. So, more like a tiny scratch? It's hard for me to conceptualize the impact of hypersonic dust on a mirror

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More like a tiny crater or pockmark, although they don’t say exactly how large the meteoroid was or how much damage it caused. Apparently “micrometeoroid” refers to objects with less than a gram of mass, although I assume that this one was likely significantly less heavy than a gram, which is the case for most.

The mirrors are gold plated beryllium so it wouldn't be a crack anyway, or at least not a crack like one would think about glass cracking.

Beryllium is fairly brittle as far as metals go, so a crack wouldn't be out of the question.

But alloys don't behave like the individual elements, so Beryllium being brittle doesn't mean that the alloy also is. Just like Carbon has multiple crystallization forms with wildly different mechanical properties (graphite vs diamond)

Plating is not an alloy though?

str.replace(?,.)

How do you define "hypersonic" in a vacuum?

Ha! Greater than 0 m/s I suppose - so still technically accurate :-P

In space, nobody can year you go transsonic...

>1715 m/s same as in air but without the air.

Should've paid the extra billion for the wiper blade package

Throw a few dozen Rain-X wipers from AutoZone on that baby, she'd be good.

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