It's called the Extreme Deep Field—or XDF for short. It took ten years of Hubble Space Telescope photographs to make it, and it's the most detailed, deepest picture of the Universe ever taken, showing some of the oldest galaxies ever observed by humans, 13.2 billion years back in time.
It's a mindblowing, extremely humbling view. Not only for what it shows, but for what it doesn't show. While it contains about 5,500 galaxies, this photograph only shows a tiny part of the sky, a small slice of the Universe. As you can see in the image below (make sure to expand it to see it complete), the photo only focus on a small area of the constellation Fornax that looks ridiculous next to our Moon.
It is an insignificant part of the universe. An arbitrary sample, photographed repeatedly with the Advanced Camera for Surveys and the Wide Field Camera 3 on board the Hubble. And yet, it's bubbling with billions of stars, bursting with trillions of planets. Some of those planets, no doubt, had or have life on them.
According to Garth Illingworth—of the University of California at Santa Cruz, principal investigator of the Hubble Ultra Deep Field 2009 program—"the XDF is the deepest image of the sky ever obtained and reveals the faintest and most distant galaxies ever seen. XDF allows us to explore further back in time than ever before."
As Illingoworth says, the XDF is a "time tunnel into the distant past." Indeed, and it's the most beautiful time machine I can imagine.
This graphic shows (click to expand) the foreground (galaxies less than 5 billion light years away from us), background (between 5 and 9 billion years ago) and very far background galaxies (more than 9 billion years), which are "one ten-billionth the brightness of what the human eye can see."
This video explains how this historical image was assembled: