Terms by letter

All terms | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

ascending node

The point in an orbit (longitude) at which a satellite crosses the equatorial plane from south to north.
Source: NASA (http://earthobservatory.nasa.gov/Glossary)