A dark object may be lurking near our solar system Nicknamed “Nemesis”  this undetected object could be a red or brown dwarf star several times the mass of Jupiter.

Why do scientists think something could be hidden beyond the edge of our solar system? Originally, Nemesis was suggested as a way to explain a cycle of mass extinctions on Earth, but there are now other reasons to suspect a dark companion to the Sun.

A recently-discovered dwarf planet, named Sedna, has an extra-long and usual elliptical orbit around the Sun. Sedna is one of the most distant objects yet observed, with an orbit ranging between 76 and 975 AU (where 1 AU is the distance between the Earth and the Sun). Sedna’s orbit is estimated to last between 10.5 to 12 thousand years. Sedna’s discoverer, Mike Brown of Caltech, noted in a Discover magazine article that Sedna’s location doesn’t make sense.

"Sedna shouldn't be there,There's no way to put Sedna where it is. It never comes close enough to be affected by the Sun, but it never goes far enough away from the Sun to be affected by other stars.” M. Brown said

Top left: The inner solar system, top right: The outer planets and below right is Sedna's orbit compared. below left is the Oort cloud in comparison

Perhaps a massive unseen object is responsible for Sedna’s mystifying orbit, its gravitational influence keeping Sedna fixed in that far-distant portion of space.

“My surveys have always looked for objects closer and thus moving faste.I would have easily overlooked something so distant and slow moving as Nemesis.” M Brown said to Astrobiology Magazine

The new infrared survey space observatory WISE ( Wide-field Infrared Survey Explorer), may be able to answer the question about Nemesis once and for all. Part of the WISE mission is to search for brown dwarfs, and NASA expects it could find 1.000 of them within 25 light years of us, and thus also Nemesis

Source: Astrobiology.net