Thousands and thousands of galaxies -- about 5,500 galaxies, to be exact -- are packed into this incredible image, made from over two million seconds of total exposure time with the Hubble Space Telescope. That's the equivalent of 50 days' worth of actual telescope time, not to mention 2,000 new images added to the previous Ultra Deep Field image... and the results are simply stunning.
With the exception of a handful of foreground stars that lie within our own Milky Way galaxy, every other point of light in this image is an entire galaxy of stars in itself, and we're seeing them as they were all the way back through time and space up to 13.2 billion years ago.
In fact the most distant galaxy in this image, called UDFj-39546284, is barely visible as a dim red dot and is seen as it existed after it first formed, a mere 450 million years after the Big Bang when the Universe was only 5 percent of its current age.
"The XDF is the deepest image of the sky ever obtained and reveals the faintest and most distant galaxies ever seen," said Garth Illingworth of UC Santa Cruz, principal investigator of the Hubble Ultra Deep Field 2009 program. Like a snapshot of billions of years of galactic evolution in progress, "XDF allows us to explore further back in time than ever before."
What's even more amazing is that all of these galaxies lie in a tiny patch of sky, less than a tenth of the diameter of the full moon, located within the constellation Fornax. For an idea of how big that is, take a dime, hold it out at arm's length, and inside less than a tenth of its width -- about the size of FDR's ear -- 5,500 galaxies can be found far beyond our own. (Although seeing them requires some pretty fancy equipment; the dimmest ones above are one ten-billionth the brightness that the human eye can make out!)
Read more at Discovery News
No comments:
Post a Comment