A lunar eclipse! So it would be that instead of the red, dusky moon we get. I believe a solar eclipse would look the same on earth if it was flat and the sun/moon were overhead. Different pattern though.

Are there any flat-moon conspiracy theorists? I feel like there's way more evidence that the moon is flat. We see the same side all the time. If it were round, wouldn't we see different parts of it? We're supposed to believe that it's a spheroid orbiting us at the exact rotational speed required so that the same side is facing us all the time? Be serious.