The universe is a vast and ever-evolving space that continues to amaze mankind with its wonders. One such wonder is the Antennae galaxies, which were captured in stunning detail by the Advanced Camera for Surveys (ACS) on the NASA/ESA Hubble Space Telescope.
The Antennae galaxies are actually two once-isolated galaxies that are in the process of colliding, creating a spectacular visual display of star formation. As the galaxies interact, thousands of millions of stars are born, mainly in groups and clusters of stars called super star clusters. These clusters are the brightest and most compact, with some containing tens of thousands of stars.
The two spiral galaxies began to fuse together about 500 million years ago, making the Antennae galaxies the nearest and youngest example of a pair of colliding galaxies. Nearly half of the faint objects in the Antennae are young clusters containing tens of thousands of stars.
The orange blobs seen in the image are the two cores of the original galaxies, consisting mainly of old stars criss-crossed by filaments of dark brown dust. The galaxies are dotted with brilliant blue star-forming regions surrounded by pink hydrogen gas.
Astronomers are able to use the observations to distinguish between the stars and super star clusters created during the collision of two spiral galaxies. The results show that only about 10% of the newly formed super star clusters in the Antennae will live to see their ten millionth birthday. The majority of the super star clusters formed during this interaction will disperse, with the individual stars becoming part of the smooth background of the galaxy.
However, it is believed that about a hundred of the most massive clusters will survive to form regular globular clusters, similar to the globular clusters found in our own Milky Way galaxy.
The Antennae galaxies take their name from the long antenna-like "arms" extending far out from the nuclei of the two galaxies, which are best seen by ground-based telescopes. These "tidal tails" were formed during the initial encounter of the galaxies some 500 million years ago. They give us a glimpse of what may happen when our own Milky Way galaxy collides with the neighboring Andromeda Galaxy about 6 billion years from now.