Sedna

Sedna — dwarf planet, shown live in Cosmoscope, a real-time 3D map of the universe.

One of the most distant known worlds, on an orbit so vast a single year lasts over eleven millennia. Its extreme, detached path is a key clue in the hunt for a possible undiscovered Planet Nine.

Radius
~500 km
Discovered
2003
Year
~11,400 Earth years
Perihelion
76 AU — never comes near the planets
Aphelion
~900 AU
Region
Inner Oort Cloud

Seeing Sedna in real time

Cosmoscope puts Sedna at its true position in the solar system, computed from JPL-derived ephemeris and updated continuously. Open the live 3D view to see, in real time, how far Sedna is from the Sun and from Earth right now, how many minutes or hours light takes to cross that gap, and how fast it is moving along its orbit. Scrub the timeline to place Sedna where it was on any past date, or where it will be years from now.

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