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27 Cards in this Set

  • Front
  • Back
The geocentric theory claims that the _______ is at the _______ of the universe.
earth, center
path among the stars that the sun appears to follow
a line between the sun and planet will cover equal areas during any equal orbital time
Kepler's second law of planetary motion: law of areas
Earth's orbit around the sun
planet's circular, slightly off-center orbit
During summer in the northern hemisphere, which way is the North Pole tilted?
towards the sun
number of degrees Earth's axis is tilted
23 1/2 degrees
the force holding planets in their orbits
gravity (law of gravitation)
English mathematician and scientist who formulated the law of gravitation
Sir Isaac Newton
first person to use a telescope for astronomy
Galileo Galilei
time required for a planet to orbit the sun is proportional to its distance from the sun
Kepler's third law of planetary motion: period-distance relationship
German astronomer who formulated the three laws of planetary motion
Johannes Kepler
Kepler's three laws of planetary motion
1. elliptical orbits
2. law of areas
3. period-distance relationship
the sun is one focus of the ellipse
Kepler's first law of planetary motion: elliptical orbits
the crystal, or transparent, spheres proposed in the geocentric view of the universe
Polish astronomer who played the major role in developing the heliocentric view of the universe
Nicolaus Copernicus
view of the universe which states that the sun is the center and all heavenly bodies revolve around it
heliocentric view
the seven celestial bodies (excluding the stars) observed by the earliest astronomers
sun, moon, Mercury, Venus, Mars, Jupiter, Saturn
ancient view of the universe which states that the earth is the center and all heavenly bodies revolve around it
geocentric, or Ptolemaic, view
the turning of Earth on its axis
Kepler's major contribution to Copernican theory
elliptical orbits
term describing the sun and all other celestial bodies revolving around it
solar system
tendency of bodies in motion to remain in motion in the same direction at a constant speed
imaginary line about which the earth is spinning
date of the vernal equinox
March 21 (may vary a day because of leap year)
type of wind patterns that are evidence of Earth's rotation
date of autumnal equinox
September 22 (may vary a day because of leap year)