Kissing moons may explain why Earth's moon is so large

A plane flies looks like a tiny speck in front of a huge moon that takes up almost the entire frame.

The larger moons of Pluto and Earth likely formed through a collisional process with Charon and our moon, respectively, rather than by gravitationally capturing them. Due to Pluto and Charon's rocky, icy nature, their collision was more of a gentle short-lived kiss.

from CBC | Technology News https://ift.tt/TYvLzpb