Astronomers have speculated for years that there could be a large planet in the outer reaches of our solar system, but no such object has ever been directly observed. However, the harder we look, the more plausible the existence of “planet nine” becomes. Astronomers Konstantin Batygin and Mike Brown of Caltech have added another piece of evidence to the debate. Their observations indicate that planet nine could be causing a “wobble” in the solar system.
While we can’t see planet nine, astronomers have detected a number of bizarre effects in the solar system that could be explained by the object. Recently, an analysis of Kuiper Belt objects in the outer solar system revealed a pattern consistent with a large object in a highly elliptical orbit around the sun. Grad student Elizabeth Bailey, who works with Batygin and Brown, says that planet nine might be so massive that it’s slowly pulling the plane of the solar system out of alignment.
The new research is based on the fact that the sun rotates on a different axis than the planets do. Earth, Mars, and everything up to Neptune all move around the sun in the same flat plane. However, that plane is 6 degrees off from the sun’s axis. This doesn’t match with what we know about how solar systems form. As the dust and gas disk around a young solar system begins condensing into planets, its motion comes from the central star. Thus, everything should be on the same plane. So, something must be pulling the solar system out of alignment. That something could be planet nine.