Pluto, once defined as the ninth planet of the solar system, was demoted to dwarf planetÂ status in 2006 when a new definition of planets was drawn up by the InternationalÂ Astronomical Union (IAU) based in Prague.1 There were 3 main qualifiers for planetÂ status which included orbiting around the sun, be spherical by its own gravitationalÂ force and finally to have its neighbourhood cleared of smaller bodies, asteroid andÂ debris. Pluto qualified for the first two criteria but did not clear the last.
1. Discovered in 1930, it was named after the Roman God of the underworld due to itsÂ location away from the sun and being in perpetual darkness.
2. Pluto is named by a 11 year old girl from Oxford, England who forwarded the nameÂ to the Lowell Observatory through her grandfather.
3. A spacecraft, the New Horizons, was launched in 2006 with a planned 2015 as dateÂ of landing. Detail information about Pluto will be pending this landing.
4. Temperatures on Pluto can go down to -2400C when it is farthest from the Sun.
5. Pluto’s orbit is a 248 year long elliptical journey which is the longest as compared toÂ the other 8 planets. In comparison, Mars takes 88 earth days whereas Earth takes 365Â days.
6. When Pluto gets closest to the Sun (perihelion), the surface ice melts and forms aÂ thin extended atmosphere due to its low gravity. Once it moves furthest away fromÂ the Sun (aphelion), the atmosphere reverts to icy, freezing darkness.
7. In 1989 Pluto came within 29.7 AU of the Sun, the closest to date enabling researchÂ work. The furthest distance from the Sun is 49.3 AU. (1 AU = 93 million miles orÂ distance from earth to sun)
8. The Hubble Space Telescope photographed Pluto in 1994indicating it as redÂ composition.
9. The thin atmosphere on Pluto would be toxic to humans as it contains methane,Â ethane, carbon monoxide and nitrogen.
10.Known as retrograde rotation, the sun rises in the west and sets in the east on PlutoÂ as opposed to Earth.