Hubble images reveal a changing planet
Hubble Site
PLUTO: A QUICK GUIDE
Named after underworld god
Lost status as planet in 2006
Average of 5.9bn km to Sun
Orbits Sun every 248 years
Diameter of 2,360km
Has at least three moons
Rotates every 6.8 days
Gravity about 6% of Earth's
Surface temperature -233C
Nasa probe visits in 2015
(The quick guide provided by news.bbc.co.uk science&nature)