James Webb Telescope to uncover mysteries of Sedna one of the farthest dwarf planets

Aartist's impression of noontime on Sedna. Credit: NASA, ESA and Adolf Schaller

September 19, 2022

On September 13, 2022 , James Webb Telescope gathered data on Sedna, one of the farthest known dwarf planets within the solar system. Sedna has a diameter of approximately 800-1100 miles. Previous Spectroscopy analysis has revealed that Sedna's surface composition is similar to those of some other trans-Neptunian objects, containing a mixture of water, methane, and nitrogen ices with tholins. Its surface is one of the reddest among Solar System objects. Sedna is tied with Ceres as the largest planetoid not known to have a moon. Sedna is so far from the sun that sun's feeble rays are nearly one four-thousandth the intensity of what they are at Earth. As a result, Sedna is eternally cold at minus 400 degrees Fahrenheit, airless and icy.

Artist Visualization of Sedna Size Comparison. Credit: NASA/JPL-Caltech

Sedna Orbit Comparison Credit: NASA/Caltech

Sedna has one of the largest orbit in the Solar System. Its orbit is an exceptionally elongated orbit, and takes approximately 11,400 years to return to its closest approach to the Sun at a distant 76 AU.

As James Webb Telescope discovers new information about Sedna with these observations, NASA will release new pictures and data to the public soon. Data and images are typically released within a few months of the observation after the peer review has been completed.