연구하는 인생/Nature·Universe 173

Pluto was found to be too small for its gravity to affect the gas gian

Planets beyond Neptune From Wikipedia, the free encyclopedia (Redirected from Planet X) Percival Lowell, originator of the Planet X hypothesis Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit. The search began in the mid-19th century but culminated at the start of the 20th with Percival Lowell's quest for P..