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2007 OR10

225088 2007 OR10
Originally unofficially named ‘Snow White’

Potential Dwarf Planet of the Solar System

Proper NameNone officially assigned (originally provisionally named 'Snow White')
Minor Planet Designation225088 2007 OR10
Provisional Designation2007 OR10
Orbital Period546.6 years
Mean Distance from the Sun10,000.6 million km (highly eccentric)
66.85 AU
Rotation PeriodNot known
DiameterUncertain; probably 1,000 - 1,500 km
Mean Surface Temperature-242°C
MoonsNone known
NotesA planetoid more than a thousand kilometres in diameter, whose highly eccentric orbit carries it more than a hundred times the Earth's distance from the Sun.
2007 OR 10

Possible appearance of the dwarf planet 2007 OR10, with a reddened surface due to the presence of frozen methane. Given its diameter, this object is probably spherical, though details of its shape are not presently known.

A mysterious body that orbits through the distant reaches of the Solar System, pursuing an orbital path in the form of an elongated ellipse. At its closest approach to the Sun, its distance is only marginally greater than that of Neptune, but from that point it travels further outward than any other known body. It is currently following this outward path, and will eventually reach a point more than 100 AU from the Sun before it begins the inward leg of its Solar orbit. For comparison, Pluto's aphelion (its greatest distance from the Sun) is 48.9 AU, less than half that of 2007 OR10.

The general characteristics of this object imply that it belongs to the category defined as 'dwarf planets', though this determination has yet to be made with certainty. Both its mass and dimensions remain somewhat unclear, but it appears to be between 1,000 and 1,500 km in diameter. Assuming that it does qualify as a dwarf planet, this places it among the smaller members of that class, very roughly half the size of comparable bodies like Pluto or Eris.

On its discovery, 2007 OR10 was nicknamed 'Snow White' on the assumption that an object travelling so far from the Sun would be swathed in ices. This is indeed the case, but the methane ice that covers its surface is not white; instead, physical reactions have turned it a deep dark red in colour. There is reason to think that this body may have a weak atmosphere of gaseous methane. No satellites of 2007 OR10 are currently known.


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