Light can behave as a particle or as a wave.

The vernal equinox occurs above the same geographic point on Earth from year to year.

Blue stars emit most of their energy at shorter wavelengths than red stars.

The reason why ancient astronomers thought that Earth could not be moving was because stars lacked any measurable parallax beyond one degree.

____ has (have) wavelengths that are shorter than visible light. I. Gamma rays II. Ultraviolet light III. Infrared radiation IV. X-rays  

Stars in the same constellation

Angular distance from the horizon to the south celestial pole always equals your latitude.

The magnitude scale

The purpose of using epicycles and deferents to explain the motion of the planets in the night sky was to account for

The force due to gravity has the mathematical form .