vote that Pluto be reinstated albeit an honorary planet in our solar system
The fly by of this little planet surprised astronomers who were expecting a fearless ball of icy rock but instead found it one of the most fascination planets in our solar system
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Observations of Pluto's surface by the New Horizons spacecraft revealed a variety of surface features, including mountains that reach as high as 11,000 feet (3,500 meters), comparable to the Rocky Mountains on Earth.
While methane and nitrogen ice cover much of the surface of Pluto, these materials are not strong enough to support such enormous peaks, so scientists suspect that the mountains are formed on a bedrock of water ice. [Photos of Pluto and Its Moons]
Pluto's surface is also covered in an abundance of methane ice, but New Horizons scientists have observed significant differences in the way the ice reflects light across the dwarf planet's surface.
Another distinct feature on Pluto's surface is a large heart-shaped region known unofficially as Tombaugh Reggio (after Clyde Tombaugh). The left side of the region (an area that takes on the shape of an ice cream cone) is covered in carbon monoxide ice. Other variations in the composition of surface materials have been identified within the "heart" of Pluto.
In the centre left of Tombaugh Reggio is a very smooth region unofficially known by the New Horizons team as "Sputnik Planum," after Earth's first artificial satellite, Sputnik. This region of Pluto's surface lacks craters caused by meteorite impacts, suggesting that the area is, on a geologic timescale, very young — no more than 100 million years old. It's possible that this region is still being shaped and changed by geologic processes.
These icy plains also display dark streaks that are a few miles long and aligned in the same direction. It's possible the lines are created by harsh winds blowing across the dwarf planet's surface.
NASA's Hubble Space Telescope has also revealed evidence that Pluto's crust could contain complex organic molecules.
Pluto's surface is one of the coldest places in the solar system, at roughly minus 375 degrees Fahrenheit (minus 225 degrees Celsius). When compared with past images, pictures of Pluto taken by the Hubble Space Telescope revealed that the dwarf planet had apparently grown redder over time, apparently due to seasonal changes.
Pluto's highly elliptical orbit can take it more than 49 times as far out from the sun as Earth. Since the dwarf planet's orbit is so eccentric, or far from circular, Pluto's distance from the sun can vary considerably. The dwarf planet actually gets closer to the sun than Neptune is for 20 years out of Pluto's 248-Earth-years-long orbit, providing astronomers with a rare chance to study this small, cold, distant world.
As a result of that orbit, after 20 years as the eighth planet (in order going out from the sun), in 1999, Pluto crossed Neptune's orbit to become the farthest planet from the sun (until it was demoted to the status of dwarf planet).
When Pluto is closer to the sun, its surface ices thaw and temporarily form a thin atmosphere, consisting mostly of nitrogen, with some methane. Pluto's low gravity, which is a little more than one-twentieth that of Earth's, causes this atmosphere to extend much higher in altitude than Earth's. When travelling farther away from the sun, most of Pluto's atmosphere is thought to freeze and all but disappear. Still, in the time that it does have an atmosphere, Pluto can apparently experience strong winds.