Astronomy vocabulary Flashcards


altitude


distance in degrees from the horizon to the object

aphelion

the point in the planet's orbit that it is the farthest from the sun

axis of rotation

imaginary straight line through the Earth between the North and South
Pole, on which the Earth rotates

celestial body

natural or man-made object found in the celestial sphere

celestial sphere

imaginary sphere encircling the Earth

circumpolar constellations

constellations that are visible all year

constellation

group of stars that take the appearance of animals, humans, or objects

geocentric

the Earth is the center of the solar system

heliocentric

the Sun is the center of the solar system

horizon

where the Earth meets the sky

orbit

the path an object takes as it revolves around another object

perihelion

the point in the planet's orbit that is the closest to the Sun

retrograde

when a planet appears to be orbiting backwards, but it actually is
just slowing down

revolution

when one object moves around another object

rotation

spinning of an object on its axis

solar noon

time of day when the sun is at its highest altitude

zenith

object that is directly overhead (90 0)