Planetary scientists have successfully used the Hubble Space Telescope to boldly look out to the far frontier of the solar system to find suitable targets for NASA's New Horizons mission to Pluto. After the marathon probe zooms past Pluto in July 2015, it will travel across the Kuiper Belt - a vast rim of primitive ice bodies left over from the birth of our solar system 4.6 billion years ago. If NASA approves, the probe could be redirected to fly to a Kuiper Belt object (KBO) and photograph it up close.

As a first step, Hubble found two KBOs drifting against the starry background. They may or may not be the ideal target for New Horizons. Nevertheless, the observation is proof of concept that Hubble can go forward with an approved deeper KBO search, covering an area of sky roughly the angular size of the full Moon. The exceedingly challenging observation amounted to finding something no bigger than Manhattan Island, and charcoal black, located 4 billion miles away.

http://hubblesite.org/news_release/news/2014-35