Learn how a possible ninth planet, the theoretical Planet X, could have acquired its wide orbit in the outer Solar System - a ...

Simulations show that the stars’ tug could send Mercury, Venus or Mars crashing into Earth — or let Jupiter eject our world from the solar system.

A new analysis of planet formation models estimates the odds of a theoretical Planet Nine orbiting our sun at 40% given ...

Researchers from Rice University claim to have fresh evidence of Planet Nine - as well as a method to find it.

B rocket is being fueled for launch of a complex deep-space mission targeting both a near-Earth asteroid and a comet.