chapter 3

gravity

force of attraction between any two object

orbit

the path that a satellite follows as it revolves

revolution

the movement of one object in its orbit around another object in space

phases of the moon

the changes in the moons appearance as it obits the earth

full moon

the phase of the moon when the earth is between the sun and the moon

new moon

the phase of the moon when the moon is between the sun and the earth

lunar eclipse

a passing of the moon through the earth shadow

solar eclipse

a passing of the moon between the earth and the sun

tides

the regular rising and falling of the earth’s major bodies of water

telescope

an insturment that collects light, making faint object easier to see and enlarging distant object

crater

a circular low area surrounded by a rim most creaters are caused by an object hitting the ground

meteorite

piece of rock that hits the surface of a planet or moon after traveling through space

star

a glowing ball of hot gas that makes it own energy and light

planet

a large body in space that obits a star such as the sun

solar system

a star, such as the sun, and all the bodies that revolve around it in spaces

mass

the amount of material that an object contains

atmosphere

an envelope of gas surrounding a body in space

sunspot

dark area of the suns surface that gives off less energy than the rest of the sun

greenhouse effect

the warming of the atmosphere because of trapped heat energy from the sun