Umbral Eclipse
DefinitionAn umbral eclipse occurs when one celestial body enters the umbra, or darkest central portion, of another body’s shadow. In a lunar...
Twilight
DefinitionTwilight is the interval before sunrise or after sunset when the Sun is below the horizon but still illuminates the sky. Astronomers...
Trutine
DefinitionTrutine is an older astrological term derived from a word meaning a balance or weighing instrument. It usually refers to the Trutine...
True Solar Day
DefinitionA true solar day, also called an apparent solar day, is the interval between two successive crossings of the local meridian by...
Tropical Year
DefinitionA tropical year is the time the Sun takes, as observed from Earth, to return to the same point in the seasonal...
Tropical Signs
DefinitionTropical signs are the twelve equal, thirty-degree divisions of the tropical zodiac, a zodiac measured from seasonal turning points rather than the...
