The celestial sphere

The sky drawn as a glass sphere around the Earth. Pick a term to see what it means on the sphere, then turn the sphere, run the clock, and move yourself or the body to watch the numbers change.

May 21, 15:00 UT. Earth fixed: the sky turns west. Drag to turn the sphere; drag the body to run the clock. Not to scale: the real sphere is so large the Earth would be a point.

Celestial sphere

An imaginary sphere around the Earth, so large that the Earth is a dot at its center. Each body is drawn where its direction meets the sphere: a navigator needs only directions, never distances.

Body: Sun
Declination: N 20°13.3'
GHA: 45°51.0'

Body

Time: 15:00 UT

Date: May 21Your latitude: N 40°00.0'Your longitude: 10° E