Let's say we want to build a model of the sun and Earth alone. Earth has a radius of about 6,371 kilometers (3,959 miles), but let's represent this with a marble 1 centimeter in diameter.

This diagram easily breaks down the science of what's happening in space with the sun, moon, and Earth during the April 8 total solar eclipse.

(via minutephysics) We think of the moon as orbiting the earth, following a spiraling trajectory as the earth itself orbits the sun.But this is wrong. Not only is the moon's orbit NOT a spiral ...