Video: Pluto scientist’s biggest surprise so far

The true size of Pluto has been debated since its discovery over 85 years ago. New Horizons’ mission scientists can now answer that question with certainty, confirming that Pluto is larger than all other known Solar System objects beyond the orbit of Neptune.

Images just sent back to Earth this week of Pluto’s tiny moon tiny Kerberos taken by NASA’s New Horizons spacecraft complete the family portrait of Pluto’s moons. Kerberos has a double-lobed shape suggesting that it could have been formed by the merger of two smaller objects. It also appears to be smaller than scientists expected and has a highly-reflective surface, counter to predictions prior to the Pluto flyby in July.

On the final stretch of a speedy nine-year trek through the solar system, NASA’s New Horizons spacecraft will be awakened from hibernation Dec. 6 for an encounter with Pluto, a mysterious world that has captured imaginations and will soon be revealed in reality.