50 years earlier, researchers had tips of a world beyond Pluto

Cometary proof of a world beyond Pluto — Science News, May 6, 1972

There have actually been ideas that our planetary system may have a tenth world … In the April Publications of the Astronomical Society of the Pacific, a mathematician … provides what he states is “some really fascinating proof of a world beyond Pluto.” The proof originates from computations of the orbit of Halley’s comet.

Update

The 1972 proof never ever yielded a world, however astronomers have not stopped looking– though it ended up being a look for Planet 9 with Pluto’s 2006 change to overshadow status. In the mid-2010 s, researchers assumed that the yank of a big world 500 to 600 times as far from the sun as Earth might discuss the strange orbits of some items in the planetary system’s debris-filled Kuiper Belt ( SN: 7/23/16, p. 7). That proof may not stand up to more analysis ( SN: 3/13/21, p. 9). Scientists utilizing the Atacama Cosmology Telescope in Chile to scan almost 90 percent of the Southern Hemisphere’s sky had no luck discovering the world, the group reported in December 2021.