Hubble Finds Worlds Beyond Pluto (and Looks for More)

Image: Kuiper Belt objects
These images are from a Hubble Space Telescope survey to find Kuiper Belt objects in support of NASA's New Horizons mission to Pluto. Multiple exposures taken with Hubble tracked the objects moving against the background field of stars in the constellation Sagittarius. The white circles highlight how the objects' positions shifted between exposures taken approximately 10 minutes apart. NASA / ESA / SwRI / JHU / APL / NH KBO Search Team

Astronomers say they've discovered two icy mini-worlds in the Kuiper Belt on the solar system's edge — just two weeks after they started using the Hubble Space Telescope to look.

The fast-track discoveries, based on imagery collected on June 24, led NASA to give the go-ahead for a more intensive search for Kuiper Belt objects. The goal is to identify an object that NASA's New Horizons spacecraft could observe up close after it flies by Pluto. The Pluto encounter is due to take place on July 14, 2015, and the second encounter is expected to occur three or four years later.

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Last month's Kuiper Belt search was a tryout of sorts, to see if Hubble was capable of finding faint objects that are farther away than Pluto but close enough for New Horizons to get to. The observation team used software tools to sift through Hubble's imagery and detect the motion of the Kuiper Belt objects through the telescope's field of view. The more detailed search is expected to be completed by August.

The two objects found so far are about 4 billion miles (6.4 billion kilometers) from Earth. They're currently known as 1110113Y and 0720090F. "We'll give them better names later," a member of the observation team, Berkeley astronomer Alex Parker, said in a tweet.