The Antennae
nuclei (yellow) are
colliding to form
one giant galaxyGALAXIES11ANTENNAE
GALAXIES A well-
known collision involves
the two Antennae galaxies.
They are 45 million light-
years from Earth and were
lit up by bursts of star
formation as they collided.GALAXY FACTFILE
SATELLITE GALAXIES Most large
galaxies have smaller, satellite galaxies in
orbit around them. The Andromeda galaxy
has many satellite galaxies, two are shown in
this photo. The Milky Way has several dozen.
GALAXY CLUSTER Galaxies form
clusters because of their huge gravitational
pull. They often pull each other out of
shape and may collide. BLACK HOLE Most galaxies have
supermassive black holes at their centers.
Their gravity is so strong that not even light
can escape. We can only see the hot gas, dust,
and stars getting pulled in.SPACEColliding galaxies
Most galaxies are separated by vast
distances, but sometimes galaxies collide.
In fact, the very common elliptical
galaxies are thought to have grown
through collisions with other galaxies
long ago. During collisions, the clouds
of gas between the stars are forced
together, triggering the birth of new
stars. One of the best known examples
is the Antennae galaxies.(c) 2012 Dorling Kindersley. All Rights Reserved.(c) 2012 Dorling Kindersley. All Rights Reserved.