Only six hundred million years after the big bang, the universe was in a fog.
this is what the universe looked like before any galaxies had formed
Here, there are no luminous objects
no stars
and certainly no galaxies
When the universe cooled down after the Big Bang
electrons and protons combined
to form neutral hydrogen gas
At this time in our history
no photons could pass through
the universe was opaque.
This dark age ended when the first stars formed and their intense ultraviolet radiation
pierced the veil
by splitting the hydrogen atoms
back into electrons and protons
In this simulation
the dark areas are opaque,
the blue areas translucent.
The fog lifted
when stars were born.
These hot young stars blew away the cosmic fog of hydrogen gas with ultraviolet radiation
and these stars formed into the very first galaxies.
clearing the way for their photons
to begin their too long,
arduous journey across creation.
The first galaxies ever to form,
lifed the universal fog forever.
The era for reionization had begun.
On October 19th 2010,
astronomers announced a measurement of one of the first galaxies
ever to form in the universe,
and it formed during this period.
Sensitive instruments on the European Southern Observatory's Very Large Telescope
recorded a spectrum
of a galaxy first imaged by the Hubble Space Telescope in January, 2010
Starting with a new Ultra Deep Field image taken in January, 2010,
with the upgraded Wide Field Camera 3
sensitive to the infrared
astronomers looked at every faint galaxy within it
these faint galaxies were among the first in existence.
From these faint smudges,
candidates for further study with the ESO SINFONI spectrograph were selected.
These galaxies were so faint,
it wasn't at all clear
if a spectrum could be obtained.
Lying in a very obscure region of the Ultra Deep Field
the ESO astronomers pointed the Very Large Telescope spectrograph
at one of the faintest objects they could see in the image.
Early in time,
this galaxy was once exceedingly bright in the ultraviolet,
but by the time it's light traversed the observable universe to land on our detectors,
its photons had been diminished to a faint, red glow.
The feeble red light from this galaxy
was collected for over sixteen long hours resulting in a spectrum
with a measured redshift of 8.6
This galaxy was alive
13.1 billion years ago
when the cosmos was still in its infancy,
and its redshift is the largest ever recorded
anywhere in the universe.
Looking at galaxies this remote is very difficult,
but they're crucial to our understanding of how galaxies came into existence
This observation of a galaxy
early in the lifetime of the universe of came as a surprise
Galaxies, it seems,
have existed much earlier
than was previously thought.
This distant galaxy not only helped clear the early hydrogen fog blanketing the universe,
it is now also
helping to clear the fog of ignorance
in our understanding
of the earliest period of existence.