Pluto

• Remember that all the data is approximated, because no spacecraft has been able to reach this dwarf planet yet.
  


• °° - interesting fact

PLUTO

Name:

• Pluto's name comes from the god of the underworld, because the dwarf planet always appeared very dark.
  


• The name was proposed by an eleven year-old girl, Venetia Burney.

Statistics:

• Mass: (metric) 13,090,000,000,000,000,000,000
  


• Diameter: 2,284 km
  


• Density: 2.05 g/cm^3
  


• Revolution: 247.7 years
  


• Rotation: 6.3872 (retrograde)
  


• Distance from Sun: 5,913,520,000 km
  

• ** retrograde: backward movement of celestial bodies in an orbit.
  

Climate:

• Extremely low temperature; about 44° K and -229° C



• Pluto's atmosphere usually measures -180° C

• Pluto goes through a seasonal cycle. Astronomers began to think so when they compared two pictures taken by the Hubble Space Telescope, one in 1994 and the other in 2002-3 . The pictures who an evident change on the surface of this dwarf planet. Pluto goes through a seasonal cycle every 247.7 years, which is its revolution period.
  

Land/Atmosphere:

• Pluto is mostly made out of water ice, while its core is made out of iron and rock.
  


• Pluto's atmosphere is 90% Nitrogen (N) and 10% other complex molecules.
  


• °° Pluto's atmosphere is odd, because whenever Pluto (throughout its orbit) gets far from the Sun, the atmosphere actually freezes and falls on the planet (as solid ice). When, though, Pluto gets closer to the Sun in its orbit, the atmosphere turns into Nitrogen and other molecules again. This doesn't happen on any other planet.

Discovery:

• In 1909, Percival Lowell believed that a ninth planet in the Solar System existed. He build a whole observatory (Lowell Observatory) just to find what he temporarily called 'Planet X'. In 1915, Lowell captured a few pictures that actually caught Planet X, but he didn't notice. He died the year after, without having reached his goal.



• Fifteen years after Lowell's death, a 26 year-old, Clyde Tombaugh, was hired at the Lowell Observatory to find out if a ninth planet existed in the Solar System or if it was all Lowell's imagination.
  


• Tombaugh found the pictures taken of Planet X, published them and also understood that Lowell hadn't seen Planet X because he didn't think that it was going to be as small as it was.
  


• Once the planet was discovered, Clyde Tombaugh was sent many e-mails proposing names for the ninth planet. He accepted Pluto.
  

Moons:

• Charon, Nix and Hydra.
  


• Charon is the biggest moon of Pluto, it is very close to it and very similar. It was discovered in 1978 by James Christy. What is interesting about this moon and Pluto is that these two are so close that they share an atmosphere, they both orbit around each other and they are considered to be a double planet.
  


• A double planet is a planet that was brutally hit by an object and split into two celestial bodies. Astronomers belive that Pluto was hit by an object and so Charon was created.
  


• Charon was named after the man that brings souls in a boat underground to the river of dead people's souls.



• Nix and Hydra were discovered in 2005. It was hard for astronomers to spot them because of their very small size. Before, when they weren't sure these two moons existed, astronomers named them S/2005 P1 and S/2005 P2.

Spacecrafts:

• New Horizons was launched in 2006 and programmed to arrive to Pluto in July 2015. Its mission is to capture close.up images of Pluto and its moons, but especially exploring the Kuiper Belt.
  

Location:

• 5.9 billion km far from the Sun



• 39.48 AU far from the Sun
  


• Located in the Kuiper Belt

Planet to dwarf planet:

• This is a video that explains what a planet and a dwarf planet are. Only watch from the points 2.40 to 3.50.
  


• In order for a celestial body to be a planet, it has to have a cleared neighborhood, has to orbit around a star, and have enough gravity to pull itself to a nearly round shape.



• Instead, a dwarf planet does not have a cleared neighborhood, orbits around a star, has enough gravity to pull itself to a nearlt round shape, and finally is not a moon.



• What made astronomers wonder about Pluto being a planet was the discovery of another celestial body behind Pluto, Eris, 25% bigger than Pluto and made of the same matter. This made astronomers wonder weather there were ten planets in the Solar System or these two planets were actually part of the Kuiper Belt. Since neither of them didn't have a cleared neighborhood, they are not considered planets anymore.
  

Other facts:

• Throughout its orbit, Pluto gets closer to the Sun.



• When an object orbiting around Pluto aligns with the Sun, it blocks light to Pluto. This is an eclipse-like event happening on Pluto.
  


• Even though Pluto is made out of ice and rock, it is reddish-brown.
  


• Pluto might have been a moon of Neptune.