Andromeda Galaxy

Approximately 3 to 5 billion years from now, scientists predict the galaxy collision between our Milky Way, and Andromeda Galaxy. But don't worry, at the time, the surface of the Earth would have already become too hot for liquid water to exist, ending all life, including the humans. This would happen in about 1 billion years because the Sun will get hotter, much hotter.

Some dwarf galaxies are currently colliding with the Milky Way as we speak and are being merged into it. One of them has the name of Sagittarius Dwarf Elliptical Galaxy (SagDEG).


More from Wikipedia:
Two scientists with the Harvard-Smithsonian Center for Astrophysics stated that when, and even whether, the two galaxies collide will depend on Andromeda's transverse velocity. Based on current calculations they preduct a 50% chance that in a merged galaxy, the solar system will be swept out three times farther from the galactic core than it is currently located. They also pridict a 12% chance that the Solar System will be ejected from the new galaxy some time during the collision. Such an event would have no adverse effect on the system and chances of any sort of disturbance to the Sun or planet themselves may be remote.

(Andromeda Galaxy)

[Sources: Wikipedia (Andromeda), Wikipedia (Andromeda-Milky Way collision)]