Okay, for artistic reasons, I’d like to severely mess up or otherwise damage Earth’s moon, physically. But I’d like to do this without a) killing everyone on the planet, or b) merely reducing the moon to an amorphous cloud of powder in a decaying orbit.
But I’m wondering what kind of stuff I could do without just adding another big crater to it. Could you knock a large chunk out of it, while leaving the rest of it mostly spherical, so it’d look something like this from Earth? Or give it a visible ring system of it’s own that would last indefinitely? Or any other screwy astronomical oddities that at least wouldn’t be physically impossible?
Well at least you’re better than Professor Abian who wanted to completely destroy the moon. How exactly he wanted to do that was not clear. I mean if you just keep bombing it, you’ll just get, as you say, an amorphous cloud of powder. Only it wouldn’t exactly be a cloud – it would mainly fall back into a spherical object about the same size as it is today.
If you did, the sides of that crater would quickly slump in and it’d end up being spherical again.
Orbits around the moon are notoriously unstable, mostly due to mascons but partly due to perturbations by the sun and Earth. It wouldn’t last.
Try painting it was some bright substance. The moon has a rather low albedo, somewhere around 12%. So any bright substance you spread on it will really show up.
Even if you could just transport away a chunk of the moon, the surrounding rock would not support the depression. The rock would fall and/or squeeze in until the moon was spherical again, with a shallow “scar”, a crater, where the chunk had been taken.
I think the most visible thing you could do would be to “paint” the moon with dark and light dust. How about a yin/yang symbol? That would last essentially forever as long as the “paints” maintained their shades under ultraviolet light, cosmic rays, and solar wind.
A ring would be nice. Pulverize an asteroid, melt a comet, and merge the two far enough away from the sun that the mud ball will freeze before the water all boils away. Tow the ball into lunar orbit and wait for the water to sublime away leaving the dust to form a pretty ring. Use a lunar polar orbit such that the ring will be full-face to Earth during full the full moon. The ring will be edge on at the half moon and back to fill-face at the new moon. The ring will not last forever. Interactions between the particles will disperse them - some into space, some to crash into the moon. I don’t know how many years you’ll get, but it should be a satisfyingly long time.
One possibility would be to spin the Moon up; if it rotates fast enough it should start to flatten out visibly. I’m not sure how far you could go before it broke up though.
You probably could build a ring around it, if the components were powered somehow ( solar sails to avoid the need for fuel ? ). Or build a ring style space station around the entire equator, with space elevator “spokes” to the surface; all nice and shiny to be obvious from Earth.
In theory you could actually terraform the Moon. Add water and atmosphere, then life. The Moon is only just too small to hold an atmosphere; a terraformed Moon would retain one for a long time in human terms ( IIRC 100,000 years? ). It has been suggested that if you orbited huge membranous “shrouds” around such a terraformed Moon they would bounce the occasional wandering gas molecule back towards the surface and keep the atmosphere permanent.
Not until it’s orbit decays enough to hit the Earth’s atmosphere. At which point, I think we’ll all be too distracted by the impending life-on-Earth-destroying impact to really notice the whistling. Though it would add a nice dramatic touch to Armageddon.
A agree: a few million gallons of silver and black paint are the best bet.
I’m not sure that paint meets the OP’s requirement to “severly mess up or otherwise damage” the Moon.
But if it does, a lot more than a few million gallons will be needed. Based on coverage of a gallon per 10 m[sup]2[/sup] (which, given the Moon’s powdery surface, is seriously optimistic) a few million gallons would cover less than 1/100,000th of the surface.
You’d probably do better to deploy vast, thin sheets (of mylar, or similar material). Even then, the mass and cost (including installation) of enough to be visually significant would be far beyond prohibitive.
It’s not a matter of the moon being solid rock vs Earth being molten. At that scale, gravity exceeds the material strength of the rock, and it will flow.
Smooth it out. Just run a zen garden rake over the whole thing, shove the mountains into the craters until it’s just a smooth featureless ball from earth. It would eventually get all messed up from space rocks and such, but that’s all part of the thing. Gives you a chance to rake the other way around…
Hmmm. If you smoothed the surface of the Moon, then coated it with something highly reflective and converted it into a single vast mirror, the reflection should look interesting. Or maybe with something that refracts light into a spectrum; Rainbow Moon would be cool.
For that matter, how long would it take for it to become spherical again, if you knocked out a quarter (or another noticeably large chunk) out of it? Are we talking minutes, hours, or years?