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.

Learn the differences between our Earth, the Sun and the Moon. Then explore how together they create day and night and our different seasons with their orbits.

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.

A diagram depicting the fall equinox, one of only two times when the Earth's axis is tilted neither toward nor away from the sun. NWS Boulder You are viewing 1 of 3 images Previous Image Next Image ...