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Nemesis reborn: A new theory put forward by planetary scientist John Matese suggests that a dark, Jupiter-sized planet is lurking at the edge of our Solar System, and throwing comets at us:

In 1999, Matese 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.

This idea was a reaction to an earlier notion that a dim brown dwarf or red dwarf star, ominously dubbed Nemesis, has pummeled the Earth with deadly comet showers every 30 million years or so. Later research suggested that mass extinctions on Earth don’t line up with Nemesis’s predictions, so many astronomers now think the object doesn’t exist.

“But we began to ask, what kind of an object could you hope to infer from the present data that we are seeing?” Matese said. “What could possibly tickle [comets’] orbits and make them come very close to the sun so we could see them?”

Rather than a malevolent death star, a smaller and more benign companion called Tyche (Nemesis’s good sister in Greek mythology) could send comets streaming from the Oort Cloud toward Earth.

This news comes just a few months after other researchers said that extremely regular extinction events were evidence against the existence of Nemesis.