Astronomers have unveiled the most far-reaching glimpses into a small corner of the universe ever compiled. Some 2,000 images, taken over a decade, were collated to show objects "further back in time than ever before."
Hubble's "eXtreme Deep Field" (XDF) snapshot was compiled using images with a total exposure time exceeding 500 hours; 5,500 galaxies are visible. The massive exposure times are necessary to pick up light tens of billions of times too faint for the naked human eye to see.
"XDF is the deepest image of the sky ever obtained," astronomer Garth Illingworth from the University of California at Santa Cruz, said in a statement. "It allows us to explore further back in time than ever before."
Some of the images in the XDF are being seen as they were around 13 billion years ago, owing to the enormous distances between them and the Hubble telescope.
The furthest-flung of the galaxies pictured, codenamed UDFj-39546284, is thought to be the most distant galaxy yet discovered, believed to be roughly 13.25 billion light years away. With the so-called Big Bang, the birth of the universe, thought to have taken place about 13.7 billion years ago, that would mean the galaxy is being seen at it was less than 500 million years after the Big Bang.
Another barely-visible formation towards the top-left of the image, UDFy-38135539, is currently the most distant known galaxy; it is seen as it was 600 million years after the Big Bang.
The new XDF images incorporate some technology that was only added to the 20-year-old Hubble observatory in 2009. The Wide Field Camera 3 is capable of picking up longer light wavelengths including ultraviolet and infrared, the only way to see the most distant objects in space.
On the Hubble image above, the bright blue formations are new, colliding or merging galaxies in their energetic infancy. The red and often fuzzy formations tend to be older galaxies in decline.
msh/jr (dpa, Reuters)