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
Tadpole Galaxy Tadpole Galaxy The Tadpole Galaxy is a disrupted barred spiral galaxy located 420 million light-years from Earth in the northern constellation Draco. Its most dramatic feature is a massive trail of stars about 280,000 light-years long; the size of the galaxy has been attributed to a merger with a smaller galaxy that is believed to have occurred about 100 million years ago. The galaxy is filled with bright blue star clusters. It is hypothesized that a more compact intruder galaxy crossed in front of the Tadpole Galaxy—from left to right from the perspective of Earth—and was slung around behind the