A planet four times the size of Earth may be skirting the edges of the solar system beyond Pluto, according to new research. Too distant to be easily spotted by Earth-based telescopes, the unseen planet could be gravitationally tugging on small icy objects past Neptune, helping explain the mystery of those objects' peculiar orbits.
A planet four times the size of Earth may be skirting the edges of the solar system beyond Pluto, according to new research. Too distant to be easily spotted by Earth-based telescopes, the unseen planet could be gravitationally tugging on small icy objects past Neptune, helping explain the mystery of those objects' peculiar orbits.
