In 2003 and 2004, the “Hubble Ultra Deep Field” photograph was released. Created by collecting light over the course of many hours, the picture revealed the deepest view of the universe to date. The new eXtreme Deep Field (XDF) photograph goes even farther, by collecting the equivalent of 23 hours of exposure time, peering back 13.2 billion years into the universe’s past. Given that the universe is thought to be around 13.7 billion years old, this gives us a glimpse of the universe at its very earliest stages of development.
“The light from those past events is just arriving at Earth now, and so the XDF is a ‘time tunnel into the distant past. The youngest galaxy found in the XDF existed just 450 million years after the universe’s birth in the Big Bang.”
To create the picture, Hubble returned to the same target more than 50 times over the past decade, racking up 2 million seconds of exposure time or the equivalent of a 23-day time exposure. In addition, a new camera component was added in 2009 that increased the telescope’s sensitivity to infrared light which further enhanced the telescope’s photographic capabilities. The XDF photo was created by combining the 10 years of NASA Hubble Space Telescope photographs (more than 2,000 individual photos), from various cameras inside the telescope, taken of a patch of sky at the center of the original Hubble Ultra Deep Field. Over 5,500 galaxies are revealed in the tiny field of view located inside the constellation Fornax. The faintest galaxies are one ten-billionth the brightness of what the human eye is capable of seeing.
Scientific American magazine explained the importance of XDF:
“The photo reveals a wide range of galaxies, from spirals that are Milky Way-lookalikes, to hazy reddish blobs that are the result of collisions between galaxies. Some of the very tiny, faint galaxies could be the seeds from which the biggest galaxies around today grew.”
Hubble researcher Garth Illingworth explained what we see from this new photo:
“We see a time when the first galaxies were forming, the metals, all the elements that make our bodies, make the Earth and basically our whole solar system were starting to be built up in this time. So it was a time…when the universe was being transformed, the first galaxies were being built up, a dramatic time in the life of the universe.”
In the picture, magnificent spiral galaxies similar in shape to our Milky Way and the neighboring Andromeda galaxy appear, as do the large, fuzzy red galaxies where the formation of new stars has ceased. These red galaxies are the remnants of dramatic collisions between galaxies and are in their declining years. Peppered across the field are tiny, faint, more distant galaxies that were like the seedlings from which today’s magnificent galaxies grew. The history of galaxies — from soon after the first galaxies were born to the great galaxies of today, like our Milky Way — is laid out in this one remarkable image.
Hubble was launched in April 1990 and is a collaborative effort between NASA and the European Space Agency. It is expected to operate through the year 2018. Before the Hubble was launched, astronomers could barely see normal galaxies to 7 billion light-years away (about halfway across the universe).
The video below illustrates the massiveness of the universe by animating travel into the section of sky XDF was taken from.