Astronomers have combined a natural gravitational lens and a sophisticated telescope array to get the sharpest view ever of "star factories" in a galaxy over 10 billion light-years from Earth.
Arp 220 is a nearby example of a merged starburst galaxy similar to SMM J2135-0102. Located 250 million light-years from Earth, Arp 220 is the aftermath of a collision between two spiral galaxies. The collision, which began about 700 million years ago, has sparked a crackling burst of star formation, resulting in about 200 huge star clusters in a packed, dusty region about 5,000 light-years across (about 5 percent of the Milky Way's diameter). The star clusters are the bluish-white bright knots visible in the Hubble image.
(NASA, ESA, the Hubble Heritage-ESA/Hubble Collaboration, and A. Evans (UVa/NRAO/Stony Brook))