
NASA may shift New Horizons Pluto probe to sun-studying mission
The future of NASA's New Horizons Pluto probe is uncertain following debates at NASA over how best to use the spacecraft.
Pluto, once considered the ninth and most distant planet from the sun, is now the largest known dwarf planet in the solar system. It is also one of the largest known members of the Kuiper Belt, a shadowy zone beyond the orbit of Neptune thought to be populated by hundreds of thousands of rocky, icy bodies each larger than 62 miles (100 kilometers) across, along with 1 trillion or more comets.