Eclipses, Occultations and Transits
An eclipse is the result of the total or partial masking of a celestial body by another along an observer's line of sight. Solar eclipses result from the Moon blocking the Sun relative to the Earth; thus Earth, Moon and Sun all lie on a line. Lunar eclipses work the same way in a different order: Moon, Earth and Sun all on a line. In this case the Earth's shadow hides the Moon from view. An occultation occurs when a celestial object is eclipsed by the Moon or another solar system body. A transit is either the act of one celestial body passing in front of another or the time at which a celestial object is highest in the sky. The time at which a celestial object crosses the meridian is called the transit time.