科学美国人60秒:Pluto Killer Thinks He Has New Ninth Planet

“All those people who are mad that Pluto is no longer a planet can be thrilled to know that there’s a real planet out there still to be found.” Caltech planetary astronomer Mike Brown. He knows about those mad people—he’s the guy most responsible for demoting Pluto and messing up everyone’s mnemonic devices to remember the names of the planets: My Very Educated Mother Just Served Us Nine…it used to be pickles, but without Pluto, we don’t know.

But now Brown, who wrote the book How I Killed Pluto and Why It Had It Coming and whose twitter handle is @plutokiller, wants to return the solar system to being nine planets strong. Because he and his colleague Konstantin Batygin think they have evidence that an object that will surely qualify as being a full-fledged planet lies way out at what’s usually considered the edge of the solar system.

“When we looked at the outer solar system, we realized that while most of the very distant objects, these objects beyond Neptune, beyond Pluto, most of these objects, they all go around the sun and they’re all sort of pointing off in all different directions, but the most distant objects all swing out in one direction in a very strange way that shouldn’t happen. And we realized that the only way we could get them to all swing in one direction is if there is a massive planet, also very distant in the solar system, keeping them in place while they all go around the sun…and we started looking at this and thinking, this must be either a coincidence or it’s caused by something else, it can’t be caused by a planet because that’s crazy, there are no planets out there…and went from trying very hard to be skeptical that what we were talking about was true to suddenly thinking, oh, this actually might even be true.”

The researchers reported their finding in the Astronomical Journal. [Konstantin Batygin and Michael E. Brown, Evidence For A Distant Giant Planet In The Solar System]

The proposed planet should be more massive than the Earth, but less massive than Neptune.

“We have nothing like it in the solar system, so it’s new for us. It is however the most common mass of planets that have been found around all of the other stars. People have always looked at all these other planets in this strange mass range and said, wow, I wonder what these are, I don’t know what these are, because we don’t have anything like it in the solar system. Looks like maybe we do.”

Mister Vastly Erudite Michael Just Served Up New Planet.

—Steve Mirsky