Hubble's "Ultra Deep Field" photo

This is called the Hubble Ultra Deep Field. Starting in late 2003, astronomers pointed Hubble at a tiny, relatively empty part of our sky (only a few stars from the Milky Way visible), and created an exposure nearly 12 days long over a four-month period. The result is this amazing image, looking back through time at thousands of galaxies that range from 1 to 13 billion light-years away from Earth. Some 10,000 galaxies were observed in this tiny patch of sky (a tenth the size of the full moon) - each galaxy a home to billions of stars.  
Selected from a gallery of 50 photos chosen by The Big Picture as the most significant images of the past decade. We wish we could post all 50. Absolutely worth a click and scroll.