Andromeda Galaxy Andromeda Galaxy The Andromeda Galaxy (), also known as Messier 31, M31, or NGC 224, is a spiral galaxy approximately 780 kiloparsecs (2.5 million light-years) from Earth, and the nearest major galaxy to the Milky Way. Its name stems from the area of the sky in which it appears, the constellation of Andromeda. The 2006 observations by the Spitzer Space Telescope revealed that the Andromeda Galaxy contains approximately one trillion stars, more than twice the number of the Milky Way's estimated 200 to 400 billion stars. The Andromeda Galaxy's mass is estimated to be around 1.76 times that of the
Places in The Hitchhiker's Guide to the Galaxy the western spiral arm of the galaxy. It is home to a number of planets, including Earth and Rupert. Earth is "an utterly insignificant little blue-green planet far out in the uncharted backwaters of the unfashionable end of the western spiral arm of the galaxy". The sapient life-forms on Earth are, in descending order of intelligence, mice, dolphins and humans, the lattermost of whom may or may not be descended from a race of Golgafrinchan telephone-sanitisers, hairdressers, management consultants, and documentary film producers." These Golgafrinchans arrived in a space ark which crashed into the planet circa 2 mya, promptly christening