Archives: Glossary Terms: 691 terms

A shell of gas surrounding a small, white star. The gas is usually illuminated by the star, producing a variety ...

A planetary transit occurs when a planet passes in front of the Sun. It is then visible from Earth as ...

A solid object that is believed to exist in protoplanetary disks and in debris disks. Planetesimals are formed from small ...

A device that can be adjusted to show the appearance of the night sky for any time and date on ...

A low plain.

A high plain or plateau.

A form of ionized gas in which the temperature is too high for atoms to exist in their natural state. ...

Phase-lock-loop circuitry in telecommunications technology.

In describing the tracking motion of an AZ-EL or ALT-AZ mounted radio telescope, to "plunge" means to exceed 90° in ...

Ninth planet from the sun, sometimes classified as a small terrestrial planet.