Galileo was the first
he discovered that there were craters on the moon
I think "scientist" is an awfully strong word to use for "prehistoric human who wasn't actually blind." Crystals are pretty common and not exactly hard to spot, so it's only slightly more reasonable than asking "who was the first astronomer to discover the Moon?"
I'd have to say the first scientist who saw the moon was the first one to look up in the sky...
The first time they looked upwards after the moon had risen.
niel armstrong
Harrison "Jack" Schmitt was the first (and only) scientist, a geologist, to walk on the moon. He was part of the Apollo 17 crew, landing in December of 1972.
Galileo
The moon
The question is not clear, it could be a early caveman.
Galileo Galilei, with his home made telescope.
moon rock
If by 'discover' you mean "the first identify it, separate form the Sun and notice that it is regularly up there in the sky", that would be Adam. If you mean 'studied the moon's phases, and it's markings', Ancient Egyptians and Babylonians have left fossil records of both the Sun and the moon that they observed, lived by and worshipped.