Archives: Glossary Terms: 691 terms

Command Detector Unit onboard a spacecraft.

A grid system for locating things in the sky. It's anchored to the celestial poles (directly above Earth's north and ...

An imaginary line that divides the celestial sphere into a northern and southern hemisphere.

The imaginary horizontal line separating the two hemispheres of the celestial sphere is called the celestial horizon.

The celestial poles are imaginary lines that trace in space. From our perspective, they are the points in the sky ...

The North and South poles of the celestial sphere.

An imaginary sphere around the Earth on which the stars and planets appear to be positioned.

The outward-tending apparent force of a body revolving around another body.

The inward acceleration of a body revolving around another body.

This is a variable star whose light pulsates in a regular cycle. The period of fluctuation is linked to the ...