Too many galaxy pairs in the Local Group?
Pairs of dwarf galaxies in the Local Group are much more common than what expected from N-body/semi-analytic models of galaxy formation.
Pairs of dwarf galaxies in the Local Group are much more common than what expected from N-body/semi-analytic models of galaxy formation.
HST measurements of stellar proper motions in M31 reveal that the Andromeda galaxy is in radial (head-on collision) orbit towards the Milky Way. The huge strike will happen 4 billion years from now according to the simulations. It will likely affect also the environment of the Sun and the location of the solar system.