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GLOSSARY
aphelion: when a body is at its furthest point from the sun
astronomical unit (AU): 93 million miles, or the average distance from the earth to the sun
elongation: the angle between an interior planet (i.e. Mercury and Venus) and the sun as seen from Earth, allowing for the best viewing of that planet; when the planet is visible after sunset, it is near its greatest eastern elongation, when the planet is visible before sunrise, it is near its greatest western elongation.
equinox: when the earth's axis is neither tilted towards nor away from the sun, causing day and night to last for nearly equal amounts of time
opposition: when an outer planet (i.e. Jupiter, Saturn etc.) is directly opposite the sun, allowing for the best viewing of that planet
perihelion: when a body is as its closest approach to the sun
solstice: the longest or shortest day of the year, depending on one's location on the earth (i.e. the northern or southern hemisphere), caused by the earth's axial tilt
universal time (UT): the time astronomers usually refer to when talking about events; to convert universal time to Eastern Standard Time for the East Coast of the United States, subtract five hours from UT. For Eastern Daylight Time, subtract four hours
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