SCIENCE

Picture of the Week: A Deep View of the Universe

A new survey of a slice of the distant reaches of the universe reveals 200,000 galaxies

March 30, 2012

A selection of a new image of distant galaxies in the COSMOS field. Click to see the whole view. Image courtesy of ESO/UltraVISTA team

You aren’t looking at a picture of stars. That bright white light in the top right corner is a nearby star, but all the other points of light are incredibly distant galaxies—each roughly the size of our own Milky Way, which contains some 200 billion to 400 billion stars. The larger image from which this highlight comes contains more than 200,000 galaxies alone. And that larger image represents just a piece of a 3-degree-wide slice of the night sky. The universe, it turns out, is a really, really big place.

The photo is part of a new view of the COSMOS field, located in the Sextans constellation, released to the public last week by the European Southern Observatory. Produced by the largest survey telescope in the world, the 4.1-meter VISTA Survey Telescope at the Paranal Observatory in Chile, the image looks past the stars near us in the Milky Way and out into the great beyond.

To slowly accumulate the scarce amounts of dim light reaching us from these distant galaxies, astronomers made six thousand separate exposures of the same patch of the night sky over a combined 55 hours. It is the widest deep view of the sky ever produced by infrared telescopes, and will be used by scientists around the world to study distant galaxies and what they tell us about the early universe.