What are Solar and Lunar Eclipses?

In anticipation of the solar eclipse that is quickly approaching - just about two weeks, I thought I'd give a really brief explanation of both solar and lunar eclipses.

solar eclipse

When positioned just right, the moon {new moon} will completely block the sun in a total eclipse - this is what we'll see on August 21st. (There are also partial solar eclipses).

lunar eclipse

Now with the earth aligned in the middle, the moon {full moon} will not be exposed to the sun at all, blocked by the earth's shadow. Aristotle (384-322 B.C.)  used his observation of a lunar eclipse to prove that the earth was round.