Impact from a space rock might have formed Pluto’s heart

heart-shaped structure on Pluto

The left side of Pluto’s heart (pictured) might be the relic of an ancient impact crater, new analysis suggests.

NASA, JHUAPL, SWRI

OXON HILL, Md. — Pluto’s got a roughly 4-billion-year-old case of heartbreak. The left side of the dwarf planet’s infamous heart-shaped feature might owe its existence to a run-in with a big space rock, planetary scientist Paul Schenk reported November 10 at the 47th meeting of the American Astronomical Society’s Division for Planetary Sciences.

The area, informally called Sputnik Planum, is an 825-kilometer-wide, 4-kilometer deep basin, said Schenk, of the Lunar and Planetary Institute in Houston. And except for some erosion to the south, the basin is roughly circular, which is typical for other impact craters in the solar system. If an interplanetary interloper is at fault, it would have smashed into Pluto at least 4 billion years ago. “It’s difficult to explain by other mechanisms,” he said.


Editor’s note: This story was updated November 23, 2015, to specify throughout that the possible impact would have been in the left half of Pluto’s heart-shaped region. 

Christopher Crockett is an Associate News Editor. He was formerly the astronomy writer from 2014 to 2017, and he has a Ph.D. in astronomy from the University of California, Los Angeles.