Huge Moon Shapes the Surface of Pluto

Close-ups from NASA’s New Horizons probe show that Pluto and its Charon moon make up a kind of double planet, around which four other moons orbit chaotically.

In July 2015, the New Horizons NASA probe passes by Pluto at a distance of only 12,500 km, reaching its destination after an almost 10 year journey across the Solar System. The so far most thorough exploration of the heavenly body, which I nternational Astronomical Union astronomers degraded from the outermost planet of the Solar System to a dwarf planet in 2006, is about to begin.

Shortly before its arrival, as New Horizons takes a series of lifelike photos of Pluto and the largest of its five known moons, Charon, the small probe documents what astronomers suspected: Dwarf planet may not be the correct description. Apparently, Pluto’s relationship with Charon is so close that instead, the two of them should be characterized as a double dwarf planet. The close relationship is not only important to the two directly involved parties, it is also highly relevant for Pluto’s other moons.

MOON ROTATES 89 TIMES

New Horizons is the only craft to have visited Pluto, and one of the most important aims of the mission is mapping out Pluto’s and Charon’s exteriors and interiors.

The first series of photos demonstrates, how Charon, which weighs 1/8 of Pluto, influences the dwarf planet to such an extent that the centre of mass of the two worlds is located in between them. Consequently, Pluto differs from the other planets of the Solar System, whose centres of mass are always inside the planets.

Pluto’s and Charon’s relationship have several distinctive consequences for the dwarf planet’s four other moons, which are