On: How bad are satellite megaconstellations for astro...

[ooterness]

No. The moon is tidally locked to the Earth, so its rotation exactly matches its orbital period. If you put a telescope on the far side, it'll always be pointing away from Earth.

[joshuakogut → ooterness]

This is the principle behind the lagrange point chosen for the James Webb Space Telescope. It's occluded from the brightness of the sun by the earth.