Hubble Telescope, Earth's eye in the sky, sighted a star factory in the dusty cores of two merging galaxies 250 million light-years away in the constellation Serpen. A team of researchers from McMaster University in Canada saw more than 200 mammoth star clusters in Arp 220, a super galaxy sired by two galaxies which started merging 700 million years ago.

The star clusters are packed into a region only about 5,000 light-years across - small by endless space standards - with the biggest cluster containing enough matter to produce 10 million suns.  "This is star birth in the extreme," said team member Christine Wilson "This is a nearby look at a phenomenon that was common in the early universe, when many galaxies were merging." Based on their calculations one of the clusters was less than 10 million years old while another was 70 million to 500 million years old.  Scientists say Arp 220 will continue to produce more star clusters until it runs out of gas about 40 million years from now.