pluto

     

Pluto (pronounce /ˈpluːtoʊ/ (help·info), from Latin: Plūto, Greek: Πλούτων), also designated 134340 Pluto, is the second-largest known dwarf planet in the Solar System (after Eris) and the tenth-largest body observed directly orbiting the Sun. Originally classified as a planet, Pluto is now considered the largest member of a distinct region called the Kuiper belt. Like other members of the belt, it is composed primarily of rock and ice and is relatively small: approximately a fifth the mass of the Earth's moon and a third its volume. It has a highly eccentric and highly inclined orbit. The eccentricity takes it from 30 to 49 AU (4.4–7.4 billion km) from the Sun, causing Pluto to occasionally come closer to the Sun than Neptune. Pluto and its largest moon, Charon, are often treated together as a binary system because the barycentre of their orbits does not lie within either body. The International Astronomical Union (IAU) has yet to formalise a definition for binary dwarf planets, and until it passes such a ruling, Charon is classified as a moon of Pluto. Pluto has two known smaller moons, Nix and Hydra, discovered in 2005.

Trivia about pluto

  • Discovered in 1930, in August 2006 it was officially downgraded to a "dwarf"
  • This cartoon character debuted in 1930, the same year the object he shares a name with was discovered
  • On Nov. 13, 1999 a body circling HD 209458 became the first new planet to be photographed since this one
  • This ninth planet's unusual orbit sometimes brings it closer to the sun than the eighth planet
  • This planet is named for the god of the dead
  • Using photos he had taken the month before, Clyde Tombaugh discovered this planet February 18, 1930
  • We don't know why a mouse would have a dog, but he's Mickey's faithful pet
  • The International Astronomical Union said in 2006 that this object was really part of the Kuiper Belt, not a true planet
  • In 2006, it was downgraded to a dwarf, leaving us with just 8 planets
  • It's the only known planet in our solar system JPL spacecraft haven't visited -- & they're looking into it
  • In 1999 this will resume its rightful position as 9th planet from the sun
  • Don't blink or you'll miss this little guy, a planet that's smaller than Earth's moon
  • JPL spacecraft have visited every planet in our solar system except this one
  • On February 11, 1999 it again became the farthest planet from the sun & will remain so for 248 years
  • A 25-year-long telescope search for it ended with its discovery in 1930
  • In 1999 it will pass Neptune to become the last planet in our solar system
  • Clyde Tombaugh, the man who discovered this planet in 1930, passed away in 1997; he was 90
  • The New Horizons mission was launched to explore this planet before it was downgraded to a dwarf
  • In 1930, he appeared as Minnie Mouse's dog, Rover; in 1931 he became Mickey's dog & was renamed this
  • Dis & Orcus are alternative names for this god of the underworld
  • This Roman god shares his name with the smallest planet in our solar system
  • He starred in the cartoon "Canine Casanova" without his master Mickey Mouse
  • It's actually too small to influence other planets' orbits, the theory that led to its discovery
  • Its orbit takes about 248 Earth years, the longest of any planet in the solar system
  • It's the only planet you can't see using ordinary binoculars; you need a telescope
  • This smallest planet always keeps the same face toward Charon, its moon
  • In the time it takes this planet to orbit the sun once, you'd get over 90,000 deliveries of your daily paper
  • 7 moons of our solar system are larger than this ninth planet, which some say should be reclassified
  • This icy planet takes 248 years to complete an orbit of the sun
  • It's the only planet in our solar system discovered by an American, Clyde Tombaugh
  • Astronomer Clyde Tombaugh discovered this tiny planet in 1930
  • The Dead Kennedys sang "One-Way Ticket To" this smallest planet
  • In September 2006 it was reduced to a number--number 134340 in the catalog of minor planets
  • Some scientists want to reclassify this planet as a wayward moon
  • It's the only planet that has yet to be visited by a spacecraft
  • This planet has more in common with Triton, Neptune's largest moon, than it does with any of the other planets
  • It's the only planet not yet encountered by a space probe
  • Charon paddles around this dwarf planet
  • The one named by an 11-year-old
  • You may have noticed that this planet isn't on the same ecliptic plane as the others in the solar system
  • Astrologers still consider this a planet; it rules the sign of Scorpio
  • It's the only planet whose orbit is tilted 17 degrees off the plane of the sun's equator
  • On June 22, 1978 James W. Christy discovered Charon, a moon orbiting this distant planet
  • Moving at 2.9 miles per second, this planet has the slowest orbital speed of any planet in our solar system
  • In 2005 the Hubble Space Telescope found 2 more small moons orbiting this, making 3, including Charon
  • Some believe this planet is not a planet, just the largest known object in the Kuiper Belt
  • Clyde Tombaugh, who discovered this planet, made his telescope out of a cream separator & parts of an old Buick
  • Hades
  • In 2002 an 800-mile-diameter planetoid called Quaoar was found 1 billion miles past this 1430-mile-diameter planet
  • (Sarah of the Clue Crew stands outside the dome of the Adler Planetarium in Chicago.) The first modern planetarium in the Western Hemisphere, the Adler, opened in 1930, about the time of this planet's discovery
  • In 1905 Percival Lowell began a search for this planet, which was discovered in 1930, 14 years after his death
  • Its moon Charon is about half its size