Archives: Glossary Terms: 691 terms

Picometer (10 m).

Pioneer 10 spacecraft.

Pioneer 11 spacecraft.

Polar night happens when the entire Sun remains below the horizon all day. It only happens within the polar circle, ...

The apparent shift of the celestial poles caused by a gradual wobble of the Earth's axis.

Orbit in which the spacecraft moves in the same direction as the planet rotates. See retrograde.

In reference to a satellite, a prograde orbit means that the satellite orbits the planet in the same direction as ...

An explosion of hot gas that erupts from the Sun's surface. Solar prominences are usually associated with sunspot activity and ...

The apparent angular motion across the sky of an object relative to the Solar System.

A rotating circumstellar disk of dense gas surrounding a young newly formed star. It is thought that planets are eventually ...