Pluto Collision May Have Created Charon

Scientists think Pluto’s moon, Charon, might be the product of a massive collision between the ninth planet and a massive object from the Kuiper Belt.

Scientists at the Southwest Research institute said computer simulations of Pluto and its lone moon suggest the pair might share a similar history with Earth and its moon.

Current theory is Earth was struck by a Mars-sized object early in its history. The tremendous collision actually created a ring around Earth, which eventually condensed into the moon. One reason for the theory is Earth’s core contains much more iron and nickel than can be explained by ordinary planet-forming models.

In an article appearing in the Jan. 28 issue of the journal Science, the scientists explain how their simulations suggest that Pluto’s collision probably was with an object at least its own original size — probably from the Kuiper Belt, which includes perhaps tens of thousands of asteroid-sized bodies orbiting between Neptune and Pluto.

Earth’s moon comprises the equivalent of only about 1 percent of the planet’s mass, while Charon is about 15 percent of Pluto’s.

The scientists estimate the colliding objects each were about 1,100 miles in diameter, or about half the size of the moon.