Weather on Eris

Astronomers examining the dwarf planet/plutoid Eris, which orbits far outside even fellow dwarf Pltuo, has weather related to its position in its orbit around the sun. Winds are generated from the warm sun facing side to the cold side facing away from the sun, resulting in nitrogen and methane "snow" being deposited around the cold side pole. Eris is the largest of the dwarf planets, larger than Pluto, with a diameter of 15-1800 miles.

"Currently, Eris is at its farthest distance to the sun, called aphelion, along its about 560-year orbit, meaning the planet is nearly 100 astronomical units (AU) from the sun, or about 9 billion miles (14 billion km). Along its orbit, Eris sweeps as close as 38 AU to the sun when at perihelion. Due to Eris' tilt, a different hemisphere faces the sun when at perihelion and aphelion."

Nitrogen would sublimate (turn from ice directly to gas without passing through a liquid state) as the planet heated up, followed by the methane as the temperature increased. Researchers were looking for a reason to explain the amount of nitrogen buried below the surface of the pole they can observe at this point in the planet's orbiut and this theory appears to match the observable data.