Messier 2 is located in the constellation of Aquarius (The Water-Bearer), about 55 000 light-years away. It is a globular cluster, a spherical group of stars all tightly bound together by gravity.
Located 300 million light-years away in the constellation Coma Berenices, the colliding galaxies have been nicknamed 'The Mice' because of the long tails of stars and gas emanating from each galaxy. Otherwise known as NGC 4676, the pair will eventually merge into a single giant galaxy.
Blue straggler stars are blue, bright stars, with a higher mass than the average for a cluster, and they are expected to sink towards the centre of a star cluster over time.
It's beginning to look a lot like Christmas in this NASA/ESA Hubble Space Telescope image of a blizzard of stars, which resembles a swirling storm in a snow globe.These stars make up the globular cluster Messier 79, located about 40 000 light-years from Earth in the constellation of Lepus (The Hare).