http://www.space.com/17755-farthest-universe-view-hubble-space-telescope.html
"The light from those past events is just arriving at Earth now, and so the XDF is a 'time tunnel into the distant past,'" according to a NASA statement. "The youngest galaxy found in the XDF existed just 450 million years after the universe's birth in the Big Bang."
Hubble was only able to image these objects by amassing light in 2,000 images of the same area, with a total exposure time of 2 million seconds, through two of its cameras: the Advanced Camera for Surveys and the Wide Field Camera 3.
"The light from those past events is just arriving at Earth now, and so the XDF is a 'time tunnel into the distant past,'" according to a NASA statement. "The youngest galaxy found in the XDF existed just 450 million years after the universe's birth in the Big Bang."
Hubble was only able to image these objects by amassing light in 2,000 images of the same area, with a total exposure time of 2 million seconds, through two of its cameras: the Advanced Camera for Surveys and the Wide Field Camera 3.