Pluto is about 1,413 miles (2274 km) in diameter. This is about 1/5 the diameter of the Earth. It is smaller than a lot of the other planets' moons, including our ________________________.

Pluto's ________________________ is about 1.29 x 10²² kg; it is the least massive planet in our Solar System. Pluto is about 1/500th of the mass of the Earth. The ________________________ on Pluto is only 8% of the gravity on Earth. A 100-pound person on Pluto would weigh only ________________________ pounds.

Each day on Pluto takes 6.39 Earth days. Each year on Pluto takes 247.7 Earth years (that is, it takes 247.7 Earth years for Pluto to orbit the ________________________ once).

Pluto has a very eccentric ________________________; that means that its distance from the sun varies a lot during its orbit around the sun. Pluto also rotates about its axis in the opposite ________________________ from most of the other planets. Pluto's orbit is tilted from the plane of the ecliptic. This angle, its orbital inclination, is 17.15°. This is the largest inclination of any of the planets. Pluto's unusual orbit makes some scientists think that Pluto is not a regular planet, but perhaps an ________________________.

Pluto has one large moon, named Charon, that is almost as big as ________________________ itself. Two minuscule moons were discovered in 2005. Charon was discovered by Jim Christy in ________________________. Charon was named after the mythological demon who ferried people across the mythological river Styx into Hades