This photograph represents an instant in time as recorded by the Galileo spacecraft. The Earth and Moon scene appeared on a single frame at a distance of about 2.9 million miles. Toward the bottom of the Moon, the indentation into the bright half is the Aiken Basin. It is believed to be one of the oldest and largest lunar impacts. Credit: NASA.
Quadratic Equation Roots
At some point during our math schooling, most of us were required to memorize the quadratic solutions equation. It was confusing, because we never knew what it was really about. Here's your chance to see where that messy equation comes from.