The waning crescent moon
27.3 days old
5.6 percent lit
Is there another planet in our solar system?
February 28, 2019
By Rafi Letzter
There could be a planet hiding (click here) out on the distant frontiers of our solar system. And astronomers have published new details about what it probably looks like, if it really exists.
Planet 9, according to a new paper published online Feb. 10 in the journal Physics Reports, is probably five to 10 times the mass of Earth. And it probably travels along an elongated orbit that peaks at 400 times Earth's distance from the sun. That orbit is also likely 15 to 25 degrees off the main orbital plain of our solar system where most planets orbit.
The existence of Planet Nine, as Live Science sister site Space.com previously reported, is an idea that's become popular among astronomers ever since it was first seriously proposed back in 2014. Researchers suspect the planet's existence because of patterns of objects in the Kuiper Belt, a ring of debris in the outer solar system. Those objects tend to clump together in ways that suggest that gravity from something big out there is tugging on them....