Discovering Planet Nine

 



 "As best they can determine, the perturber is perhaps ten times more massive than Earth, or roughly half as massive as Neptune, and it is very distant indeed. It follows an eccentric orbit, meaning one that is more elliptical than circular, and comes no closer to the sun than about two hundred and fifty astronomical units. (An astronomical unit is the distance from the sun to Earth, or ninety-three million miles. Jupiter is roughly five astronomical units from the sun, and Pluto averages nearly forty.) At its farthest, the new planet is between six hundred and twelve hundred astronomical units away; if the sun were on Fifth Avenue and Earth were one block west, Jupiter would be on the West Side Highway, Pluto would be in Montclair, New Jersey, and the new planet would be somewhere near Cleveland. It takes between twelve and twenty thousand years to go once around the sun. It is an ice giant, a lonely wanderer and the gravitational bully of the outer solar system. Brown and Batygin call it Planet Nine, and Jehoshaphat, and George. “We actually call it Fatty when we’re just talking to each other,” Brown said."

read the story by
 Alan Burdick

 Discovering Planet Nine - The New Yorker