Explanation:
What did the first galaxies look like?
To help answer this question, the Hubble Space Telescope has just finished taking the
eXtreme Deep Field (XDF), the deepest image of the universe ever taken in
visible light.
Pictured above, the XDF shows a sampling of some of the
oldest galaxies ever seen,
galaxies that formed just after the
dark ages, 13 billion years ago, when the universe was
only a few percent of its present age.
The Hubble Space Telescope's
ACS camera and the infrared channel
of the WFPC3 camera took
the image.
Combining efforts spread over 10 years, the
XDF is more sensitive, in some colors,
than the original Hubble Deep Field (HDF), the
Hubble Ultra Deep Field (HUDF) completed in 2004, and the
HUDF Infrared completed in 2009.
Astronomers the world over will likely study the
XDF for years to come to
better understand how stars and galaxies formed in the early universe.
