Antennae colliding galaxies, Hubble Space Telescope image. The Antennae (NGC 4038 and NGC 4039) are formed of two galaxies colliding due to mutual gravitational attraction. The nuclei (yellow) of the galaxies are at lower left and upper right. Numerous dark lanes of dust are seen silhouetted against the bright parts of the galaxies. The interaction has caused a huge swathe of starbirth, as seen by the abundance of young blue stars and the vast pink emission nebulae, in which stars are born. The Antennae lie some 62 million light years from Earth in the constellation Corvus. Image data collected by the Advanced Camera for Surveys in 2004 and 2005.