FIELD GUIDE
Pluto
The dwarf planet
Once counted as the ninth planet, Pluto was reclassified as a dwarf planet in 2006 after astronomers found it shares its icy neighborhood with countless similar bodies. It remains the largest known object in the Kuiper Belt, a frozen world of nitrogen ice and a single oversized moon almost half its size.
Explore in the Voyage →Stats
- DIAMETER
- 2,377 km
- DISTANCE FROM SUN
- 5,906.4 million km
- DAY LENGTH
- 153.3 hours
- TEMPERATURE
- -240°C to -218°C
Facts
Reclassified as a dwarf planet in 2006, sparking a debate that still runs today
NASA's New Horizons flew past in July 2015, returning the first close-up images
Its largest moon, Charon, is about half Pluto's diameter — nearly a double world
Pluto has a heart-shaped nitrogen-ice glacier known as Tombaugh Regio
One orbit of the Sun takes 248 Earth years
Moons
- Charon — Charon is so large relative to Pluto that the two are tidally locked, always showing the same face to each other.
Mission — The New Horizons Flyby
Fly past the last unexplored world of the original nine -- and watch its status get complicated.
IN THIS MISSION:
- The Heart
- A World Still Alive
- What Is a Planet?