Terms
The force of attraction that exists between any two objects
Gravity
The largest heavnely bodies that orbit the sun
Planets
The time it takes for the moon to complete a full cycle in its orbit around the earth
Lunar month
Created the planets
God
What is the name for the spinning of the earth?
Rotation
To revolve around
The time required for the earth to complete one revolution around the sun; equal to 365 1/4 days
Solar year
The ability of the earth's atmosphere to retain heat around the earth
Greenhouse effect
Discovered the law of universal gravitation
Sir Isaac Newton
What is the name for a single trip around the sun (or other heavenly body)?
Revolution
A symmetrically shaped oval
Ellipse
The sun and all the heavenly bodies that orbit it
Solar system
The time it takes for a comet to complete an orbit around the sun
Period
Discovered that the planets do not travel in perfect circles, but in ellipses; formulated three laws of planetary motion
Johannes Kepler
What is a space particle traveling within the earth's atmosphere called?
Meteor
The distance between the earth and the sun; equal to 93 million miles
Astronomical unit
The blanket of air that makes the earth hospitable for living things
Atmosphere
"seas"; large, dark-colored plains on the surface of the moon
Maria
Presented the idea that all the planets orbit the sun, and that the earth itself is also a planet
Nicolaus Copernicus
What is a small, rocky object that orbits the sun called?
Asteroid
The two special points in an ellipse
Foci
A region of the atmosphere, located between 10 and 30 miles above the earth's surface, that filters out most of the harmful ultraviolet radiation from the sun
Ozone layer
A group of asteroids located in the inner solar system, many of which cross paths with the earth
Near-earth asteroids
Presented the idea of an earth-centered universe
Claudius Ptolemy
What are the three parts of a comet?
Nucleus, coma, tail