Object Analysis

Sedna (90377 Sedna) is a large minor planet in the outer reaches of the Solar System that is currently in the innermost part of its orbit. Discovered in 2003, it is one of the most distant known objects in the Solar System, with an orbit that takes it roughly 11,400 years to complete.

Sedna's orbit is exceptionally elongated, with its farthest point (aphelion) estimated at 937 AU—over 30 times the distance of Neptune from the Sun. Its surface is one of the reddest in the Solar System, similar to the color of Mars, which is likely due to the long-term irradiation of organic ices on its surface.

The origin of Sedna’s strange orbit remains a mystery. Some astronomers suggest it was pulled into its current path by a passing star in the Sun's birth cluster, while others argue it is evidence of a large, undiscovered "Planet Nine" lurking in the far reaches of the Kuiper Belt.