Milky Way and Andromeda Galaxies Have the Same Mass

This illustration shows what the Milky Way and the Andromeda galaxy might look like 4 billion years from now during the merger of the two galaxies. (ICRAR)

Rick Pantaleo

February 16, 2018

In 2012, NASA astronomers predicted that our Milky Way galaxy will collide and merge with its neighboring Andromeda galaxy in about 4 billion years.

Scientists said that when this galactic collision takes place, Andromeda, which was thought to be two to three times the size of the Milky Way – will completely engulf our galaxy.

Now, an international team of researchers finds that both galaxies are about the same size.

Past studies have determined the Milky Way has a mass some 750 billion times that of the sun.

Using a new scientific technique, the researchers have determined that the Andromeda galaxy is about 800 billion times more massive than our sun.

The researchers say that in light of their findings that both galaxies are nearly equal in mass, new simulations are needed to determine what will happen when Andromeda and the Milky Way do collide.