Sedna is a dwarf planet in the extreme outer reaches of our solar system, discovered in 2003 by Mike Brown, Chad Trujillo, and David Rabinowitz.

It has a highly elliptical orbit, taking roughly 10,500 to 12,594 years to complete one revolution, with surface temperatures never exceeding -240°C.

It is one of the reddest objects in the solar system.

Key Characteristics of 90377 Sedna

Discovery:

November 14, 2003, by Mike Brown, Chad Trujillo, and David Rabinowitz.

Size:

Estimated to be between 1180 and 1800 kilometers in diameter, placing it among the largest known trans-Neptunian objects.

Orbit:

Highly elliptical, ranging from 76.37 AU (perihelion) to 1006.83 AU (aphelion) from the Sun.

Surface:

Extremely red in color, likely due to a hydrocarbon sludge called tholin. It is composed of a mixture of water, methane, and nitrogen ices.

Rotation:

Completes a rotation on its axis in about 10.27 hours.

Temperature: Temperatures never rise above 33 Kelvin (-240°C or -400°F), making it one of the coldest places in the solar system.

Sedna is classified as a trans-Neptunian object and a possible dwarf planet, residing far beyond the Kuiper Belt, representing one of the most distant known objects in the solar system.