Recently discovered a new planet Sedna (Sedna), probably has a moon. This is indicated by indirect evidence, such as the planet's period of revolution around the axis.
However, as yet have not defined the status of the planet itself — a group of astronomers argue that it is considered a planet, and that — an asteroid. So the "tenth planet" — is not yet fully legal definition for a new object.
The new estimate of the diameter of Sedna — 1700 kilometers.
The orbit of the planet is extended, and its current monstrous distance from the Earth and the Sun — perhaps not the closest to our star point of the orbit of Sedna. Said distance is 13 billion kilometers, according to a new estimate.
With this value, we observe a distant planet from the Sun and Earth, it's almost the same thing. Recall from the Sun to the Earth — 0.15 billion kilometers.
Sedna runs around the sun for 10,500 years. And at the far point of the orbit, it is removed from it by 130 billion miles. You can imagine how cold reigns there, if it is the temperature at the surface of 240 degrees below zero Celsius.
The new planet was very red and extremely bright. This combination is extremely unusual for the solar system, has baffled scientists. Now they are trying to determine what made from Sedna.