Pluto's brightness changes as it rotates, revealing large light and dark regions.
Pluto was discovered in 1930 by American astronomer Clyde Tombaugh.
Student Venetia Burney suggested the name 'Pluto' in 1930; our student-built interplanetary dust counter is named in her honor.
Pluto’s moons are named Charon, Nix, Hydra, Kerberos and Styx.
Pluto-Charon is the solar system's only known binary planet.
New Horizons' science instruments were built in Texas (SWAP, Alice), Colorado (Ralph, SDC) and Maryland (LORRI, PEPSSI, REX).
Cool facts about Pluto, the Kuiper Belt and the first mission to explore this mysterious region
- Pluto orbits the Sun once every 248 years.
- A person on Pluto would weigh 1/15 what they weigh on Earth - for comparison, the astronauts on the Moon had 1/6 of their Earth weight.
- Pluto is named after the Greek god of the underworld.
- The symbol for Pluto ("PL") is tribute to Percival Lowell, who started the search for the ninth planet in the early 1900s.
- Charon is 20 times closer to Pluto than our moon is to Earth.
- Pluto was discovered in 1930 by American astronomer Clyde Tombaugh.
- American astronomers James Christy and Robert Harrington discovered Charon in 1978.
- Charon is named after the mythological boatman who ferried souls across the river Styx to Pluto for judgment.
- At 1,470 miles (about 2,370 kilometers) across, Pluto could fit between Washington, D.C. and Denver, Colorado.
- Charon is half of Pluto's diameter - making it the largest satellite relative to the planet it orbits.
- Pluto is an ice dwarf - a "new" type of planet common to the deep outer solar system.
- Pluto-Charon is the solar system's only known binary planet.
- Pluto's surface is among the most contrasty in the solar system.
- Pluto has weather, winds, hazes, chemistry and an ionosphere.
- Pluto's estimated surface temperature falls between --378 to --396 degrees F (-228 to -238 C).
- Pluto is one of only two planets that rotates on its side - Uranus is the other.
- Pluto's surface has nitrogen, methane and carbon monoxide ices on it.
- A radio signal moving at the speed of light takes about 4 hours to reach Pluto from Earth.
- The Kuiper Belt is a collection of icy, rocky objects residing beyond Neptune's orbit.
- The first Kuiper Belt Object (after Pluto) was discovered in 1992.
- Some Kuiper Belt Objects (like Pluto) have an average reddish color, while others are gray.
- Pluto's moons are named Charon, Nix, Hydra, Kerberos and Styx.
- An American team led by Alan Stern and Hal Weaver discovered Nix and Hydra in 2005.
- The first letters of Nix and Hydra are a nod to the New Horizons mission.
- Mark Showalter led the teams that discovered Styx and Kerberos.
- Moons Nix and Hydra are roughly 5,000 times fainter than Pluto itself.
- Nix and Hydra are two to three times as far from Pluto as Pluto's largest moon, Charon.
- Nix is named after the goddess of darkness and night.
- Hydra is named after the terrifying monster with nine heads and a serpent's body.
- Kerberos is named after the three-headed dog that guards the underworld.
- Styx is named after the goddess of the river with the same name in Pluto's underworld.
- The discovery of Styx was announced in July 2012.
- New Horizons' science instruments were built in Texas (SWAP, Alice), Colorado (Ralph, SDC) and Maryland (LORRI, PEPSSI, REX).
- The New Horizons dust counter is the first student-built instrument on a NASA planetary mission.
- Scientists once thought Pluto was a moon of Neptune or an escaped giant asteroid,
- New Horizons is already flying through the Neptune Trojan asteroid cloud, but won't pass close to any known asteroid.
- The RTG that powers New Horizons is a spare from Galileo-Cassini, rebuilt for this mission.
- Pluto's brightness changes as it rotates, revealing large light and dark regions.
- Student Venetia Burney suggested the name 'Pluto' in 1930; our student-built interplanetary dust counter is named in her honor.
- Pluto atmospheric models reveal that both ethane and acetylene should be produced by chemical reactions and found on the surface.
- Pluto's last time at aphelion - the farthest point in its orbit - was 1865.
- Pluto next reaches aphelion - the farthest point in its orbit - in 2112.
- New Horizons arrives at Pluto exactly 50 years after the first successful Mars mission, Mariner 4.
- Pluto is the only known Kuiper Belt Object with multiple moons.
- New Horizons is the first mission since Voyager to launch to an unexplored planet.
- New Horizons' high-gain dish antenna is 2.1 meters (83-inches) in diameter.
- New Horizons' Atlas V551 launch vehicle was nearly 200 feet tall.
- The 2007 Jupiter gravity assist added about 9,000 mph to New Horizons' speed.
- New Horizons carries the most capable science payload ever launched on a first reconnaissance mission to an unexplored planet.
- Atmospheric surface pressure on Pluto is about 100,000 times less than on Earth.
- The Kuiper Belt is often called the -Third Zone- of our planetary system, swirling beyond both the inner zone of rocky planets and middle zone of gas giants.
- The Kuiper Belt is the largest structure in our planetary system.
- The Kuiper Belt holds an estimated 100,000-plus miniature worlds with diameters larger than 100 kilometers.
- New Horizons carries a CD containing some 435,000 names of people who signed up online to send their names to Pluto.