The Ptolemaic model of the universe was heliocentric.

What is a blackbody?

The ecliptic can be defined as

A solar eclipse that occurs when the Moon’s umbra reaches Earth’s surface is called

The Moon always keeps the same side facing Earth and therefore Earth always keeps the same side facing the Moon.

Bluer stars are brighter than redder stars of the same size. Assume both are typical stars.

The full Moon is brighter than Venus regardless of how bright Venus is in the sky on any night as viewed from Earth.

The gibbous Moon is never visible in the daytime sky.

As seen from the Earth’s southern hemisphere, the celestial equator passes

An observer in the Northern Hemisphere watches the sky for several hours. Due to the motion of Earth, this observer notices that the stars near the north celestial pole appear to move