KB: We asked ourselves, "what obliquity, what misalignment would Planet Nine induce in the solar system?" because it must induce some. We know that Planet Nine's orbit in inclined. As a result, when Planet Nine torques the rest of the solar system, the two sort of act as two precessing tops.

In the lowland tropics of northern Colombia, 60 miles from the Caribbean coast, Cerrejón is an empty, forbidding, seemingly endless horizon of dusty outback, stripped of vegetation and crisscrossed with dirt roads that lead to enormous pits 15 miles in circumference. It is one of the world's largest coal operations, covering an area larger than Washington, D.C.

We're going to Titan, and we're going in style. NASA announced on Thursday its next great solar system exploration mission. "Dragonfly" involves an ambitious plan to send a rotorcraft -- essentially a large drone -- to Saturn's moon, Titan.