Show Details

Pluto’s Origins

March 30, 2016

A violent collision between two worlds may have given rise to Pluto and its satellites.


nh-charon-neutral-bright-release NASA JHUAPL SwRI July 14 2015 enhanced color

An enhanced color view of Pluto’s largest satellite, Charon, taken by New Horizons on July 14, 2015. (NASA/JHUAPL/SwRI)


The crazy, mixed up Pluto family. I’m Bob Hirshon and this is Science Update.

When the New Horizons spacecraft flew by Pluto, its companion world, Charon and four much smaller moons, they assumed it was an orderly little family, rotating and orbiting slowly along the same plane, like the Earth and Moon.

HAL WEAVER (Applied Physics Laboratory, Johns Hopkins University):

It’s not like that at all; it’s almost like the opposite. These things are like spinning tops, the directions of their poles are almost completely, almost ninety degrees away from the direction of Pluto and Charon’s pole, which are aligned with each other.


That’s planetary scientist Hal Weaver of the Johns Hopkins University Applied Physics Lab. In the journal Science, he and his colleagues report that these eccentric orbits and rapid spin rates suggest a violent history in which two Pluto-sized objects collided, spawning a ring of debris that coalesced into the four smaller worlds. I’m Bob Hirshon, for AAAS, the science society.