After completing a deep search using the Hubble Space Telescope, scientists have identified three Kuiper Belt Objects (KBO) that New Horizons can actually reach after it flies past Pluto next year.
The KBOs Hubble found are each about 10 times larger than typical comets, but only about 1-2 percent of the size of Pluto. Unlike asteroids, KBOs have not been heated by the sun and are thought to represent a pristine, well preserved deep-freeze sample of what the outer solar system was like following its birth 4.6 billion years ago. The KBOs found in the Hubble data are thought to be the building blocks of dwarf planets such as Pluto.
I think it remarkable that in the vastness beyond Pluto they were able to find any objects that also happen to be within the narrow path that New Horizons must fly after it passes Pluto in July.