Window on Infinity: Pictures From Space

Visible on the upper left, NGC 4038 used to be an ordinary spiral galaxy, until NGC 4039, toward its right, collided with it, producing the cosmic wreckage known as the Antennae. For all the Antennae's violent appearance, few if any stars were harmed in in it creation. Galaxies are far more empty space than mass, and they typically pass right through each other.