ASTR 101 Final

ecliptic

The path that the Earth follows as it orbits the Sun.

circumpolar stars

Stars that are located near the north celestial pole and always remain above the horizon.

zodiac

A band of the sky divided into twelve signs, which correspond to different constellations that appear at various times of the year.

synchronous rotation

The phenomenon where the Moon takes the same amount of time to rotate on its axis as it does to orbit Earth, resulting in only one side being visible from Earth.

eclipses

Events that occur when the Sun, Moon, and Earth align, but do not happen every month due to the tilt of the Moon's orbit.

Copernican Revolution

The shift from a geocentric (Earth-centered) model of the universe to a heliocentric (Sun-centered) model proposed by Copernicus.

Kepler's First Law

The orbits of planets are ellipses with the Sun at one focus.

Doppler effect

The change in frequency of a wave in relation to an observer moving relative to the wave source.

refracting telescopes

Telescopes that use lenses to bend light rays to form images.

reflecting telescopes

Telescopes that use mirrors to reflect light and form images.

greenhouse effect

The trapping of heat in a planet's atmosphere by gases that allow sunlight to enter but prevent heat from escaping.

solar prominences

Bright loops of plasma that extend out from the Sun's surface, following magnetic field lines.

habitable zone

The region around a star where conditions are right for liquid water to exist.

thermal radiation

The emission of radiation from hot objects, which can be observed in different colors depending on the temperature.