Sedna

SOUND ON!

A warm THANK YOU to Sabine Berndt, Birgit Schweda and Nadja Zimmer for your voices on this small soundexperiment. – ©/® by Jo Stein  –  all rights reserved

90377 Sedna, or simply Sedna, is a large planetoid in the outer reaches of the Solar System that was, as of 2015, at a distance of about 86 astronomical units (1.29×10¹⁰ km; 8.0×10⁹ mi) from the Sun, about three times as far as Neptune. Spectroscopy has revealed that Sedna’s surface composition is similar to those of some other trans-Neptunian objects, being largely a mixture of water, methane, and nitrogen ices with tholins. Its surface is one of the reddest among Solar System objects. It is a possible dwarf planet. Sedna is approximately tied with 2002 MS4 as the largest planetoid not known to have a moon.