If you’re not up on astronomical conspiracy theory, “Nemesis” is the name for a hypothetical small star/very large planet that, one, we can’t see and, two, periodically causes all kinds of havoc by sending comets and other debris hurtling out of the Oort Cloud toward Earth. That’s not precisely what Wired is reporting on. They’re just writing about the discovery of some kind of very large, unseen planet hurtling comets out of the Oort Cloud:
In 1999, [John Matese of the University of Louisiana] and colleague Daniel Whitmire suggested the sun has a hidden companion that boots icy bodies from the Oort Cloud, a spherical haze of comets at the solar system’s fringes, into the inner solar system where we can see them.
In a new analysis of observations dating back to 1898, Matese and Whitmire confirm their original idea: About 20 percent of the comets visible from Earth were sent by a dark, distant planet.
…
After examining the orbits of more than 100 comets in the Minor Planet Center database, the researchers concluded that 80 percent of comets born in the Oort Cloud were pushed out by the galaxy’s gravity. The remaining 20 percent, however, needed a nudge from a distant object about 1.4 times the mass of Jupiter.
“Something smaller than Jovian mass wouldn’t be strong enough to do the deed,” Matese said. “Something more massive, like a brown dwarf, would give a much stronger signal than the 20 percent we assert.”
So that’s reassuring then.