Astronomy Picture of the Day

Explanation: Some 60 million light-years away in the southerly constellation Corvus, two large galaxies have collided. But stars in the two galaxies - NGC 4038 and NGC 4039 - don't collide in the course of the ponderous, billion year or so long event. Instead, their large clouds of molecular gas and dust do, triggering furious episodes of star formation. Spanning about 500 thousand light-years, this stunning view reveals new star clusters and matter flung far from the scene of the accident by gravitational tidal forces. Of course, the visual appearance of the far-flung arcing structures gives the galaxy pair their popular name - The Antennae. Recorded in this deep image of the region at the tip of the upper arc is a tidal dwarf galaxy NGC 4028S, formed in the cosmic debris.