Yes, METEOR is a Scrabble word!

Letter values in Scrabble US: M 3, E 1, T 1, E 1, O 1, R 1.

Is it a valid word?

METEOR is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

(astronomy) any of the small solid extraterrestrial bodies that hits the earth's atmosphere
a streak of light in the sky at night that results when a meteoroid hits the earth's atmosphere and air friction causes the meteoroid to melt or vaporize or explode

Also: shooting star.