astronomy The study of objects in outer space

astronomy The study of objects in outer space – outside Earth’s atmosphere

universe Everything that exists, including objects & energy, throughout time & space

solar system The sun and celestial bodies that orbit around it

rotation The spin of an object around its center point or axis

revolution The orbit of one object around another object

equinox The position of the Sun is exactly over the equator

solstice Moment in the year when the Sun’s path is farthest north or south from Earth’s equator

waxing The lit part of the moon becomes larger

waning The lit part of the moon becomes smaller

tide The rising and falling of the surface of the ocean caused by the gravitational force of the moon & sun

eclipse The movement of one object in the solar system into the shadow of another object, blocking it from view http: //www. fearofphysics. com/Sun. Moon/eclipse. html

planet Celestial body in orbit around the sun

moon Natural satellite that revolves around a planet or other celestial object other than a star http: //www. fearofphysics. com/Sun. Moon/sunmoon 1. html

asteroid Chunk of rock and metal that orbits the Earth

comet Chunk of ice and rock that orbits the Sun Halley’s comet comes around every 75 years/2061

meteoroid Small, rocky particles that move through space

meteor Meteoroids that enter Earth’s atmosphere, producing a streak of light

star Large sphere of hydrogen gas hot enough for nuclear reactions to occur in its core

Light year The distance light travels in one year

galaxy Huge collection of stars, gas, and dust