Content Starts Here
Pluto (astronomy)
Encyclopaedia Search
Pluto (astronomy)
Dwarf planet. Until its reclassification in 2006 it was considered to be the smallest and, usually, outermost planet of the Solar System. The existence of Pluto was predicted by calculation by US astronomer Percival Lowell and located by US astronomer Clyde Tombaugh in 1930. Its highly elliptical orbit occasionally takes it within the orbit of Neptune, as in 1979–99. Pluto has a mass about 0.002 of that of Earth.
Mean distance from the Sun
5.8 billion km/3.6 billion mi
Equatorial diameter
2,300 km/1,438 mi
Rotation period
6.39 Earth days
Year
248.5 Earth years
Atmosphere
thin atmosphere with small amounts of methane gas
Surface
low density, composed of rock and ice, primarily frozen methane; there is an ice cap at Pluto's north pole
Satellites
one moon, Charon
© Research Machines plc 2008. All rights reserved. Helicon Publishing is a division of Research Machines plc.
Advertisement starts
Advertisement ends
Related Links
Vatican City State Flag
The emblem reflects the Vatican's importance as the headquarters of the Roman Catholic Church. The colours of the flag are based on the gold and silver of the papal keys. Effective date: 8 June 1929.
>>
Advertorial
Find out how to buy the things you've always wanted and sell the things you don't on ebay.
Advertisement starts
Advertisement ends
Font size
Mail
My account
Help
CommunityPage Footer
Print now
Send to a friend
Related articles
Related products
Access keys
You will need to use different key combinations in order to use access keys depending on your internet browser, find out which on our accessibility page.
- (0) Navigate to Accessibility page.
- (1) Navigate to Home page.
- (2) Navigate to My email.
- (3) Navigate to My Account.
- (4) Navigate to Site Map page.
- (5) Navigate to Contact us page.
- (6) Navigate to Members channel.
- (7) Navigate to Services channel.
- (8) Navigate to News & Info channel.
- (9) Navigate to Entertainment channel.
- ([) Skip down to the Primary navigation block.
- (]) Skip down to the more links within this section block.
- (=) Bypass all navigation and jump to the content.