Is This the Most Distant Galaxy Ever Seen (by Humans)?

By Rebecca J. Rosen

New data from NASA's Hubble and Spitzer space telescopes capture light that traveled 13.2 billion light years, making the galaxy nearly as old as the Universe.

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NASA

It may not look like much, but that fuzzy red orb may be light from the most distant galaxy ever seen, and the light coming from it has traveled 13.2 billion light years. That means that the light now reaching us shone from that galaxy when our Universe, now some 13.7 billion years old, was just ("just") 500 million years old. According to a new paper in Nature, this galaxy may have emerged less than 200 million years after the Big Bang. By studying it further, scientists hope to gain new clues about the Universe's earliest stars and galaxies, whose formation ended the starless period astronomers refer to as the cosmic dark ages.

Galaxies this far away "remain largely unexplored because they are at or beyond the sensitivity limits of existing large telescopes," the paper explains. But NASA's Hubble and Spitzer space telescopes were able to capture traces of it in five different wavebands (four from Hubble, one from Spitzer). The measurements were possible because of "gravitational lensing," a phenomenon identifed by Albert Einstein that refers to the magnification of light by gravity. In the case of this discovery, light from this galaxy was brightened by a galaxy cluster that stands in the path between us and the newly discovered galaxy.

The galaxy is thought to be small -- about one percent of the mass of the Milky Way. This fits in with theories about early galaxy formation, which predict that larger galaxies did not arrive until much later.

Astronomers are looking forward to 2018, when the James Webb Telescope is expected to launch, when they should be able to get an even more detailed pictures of this place so far away, and bit by bit expand our understanding of how our Universe took shape.

This article available online at:

http://www.theatlantic.com/technology/archive/2012/09/is-this-the-most-distant-galaxy-ever-seen-by-humans/262592/