The Andromeda Galaxy . also known as Messier 31 , M 31 , or NGC 224 , is spiral galaxy approximately , 780 kiloparsecs , 2.5 , million light years , from Earth . It is the nearest major galaxy to the Milky Way and was often referred to as the Great Andromeda Nebula in older texts . name from the area of the sky in which it appears , the constellation of Andromeda which was named after the mythological princess Andromeda Being approximately 220,000 light years across:
The Andromeda Galaxy is 2 million light years away from us so what we see now is how it appeared 2 million years ago. It will collide with our Milky Way in 2 billions years from now. The two galaxies are heading towards each other at a rate of 430 km/hr.