Thursday, December 13, 2012

Taking census of the galaxies: How big is our universe and its realms



Using NASA's Hubble Space Telescope, astronomers announced Dec. 12
they have seen further back in time than ever before and have
uncovered a previously unseen population of seven primitive galaxies
that formed more than 13 billion years ago, when the universe was
less than 3 percent of its present age. The deepest images to date
from Hubble yield the first statistically robust sample of galaxies
that tells how abundant they were close to the era when galaxies
first formed.

The greater depth of the new Hubble images, together with a carefully
designed survey strategy, allows this work to go further than
previous studies, thereby providing what researchers say is the first
reliable galaxy census of this epoch. Notably, one of the galaxies
may be a distance record breaker, observed 380 million years after
the birth of our universe in the theorized big bang.

Looking deeper into the universe also means peering further back in
time. The universe is estimated to be 13.7 billion years old. The
newly discovered galaxies are seen as they looked 350 to 600 million
years after the big bang. Their light is just arriving at Earth now.

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