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10 Cards in this Set

  • Front
  • Back
The tiny building blocks of the planets that formed as dust particles stuck together and grew in size.
The spinning motion of a body on its axis
The elliptical motion of a body as it orbits another body in space.
A closed curve in which the sum of the distances from the edge of the curve to two points inside the ellipse is always the same.
Astronomical Unit
The average distance between the Earth and the sun or approximately 150,000,000 km
Law of Universal Gravitation
All objects in the universe attract each other by a force called gravity. The size of the force depends on the masses of the objects and the distance between them.
Terrestrial planets
the small, dense, rocky planets of the inner solar system.
Prograde Rotation
The counterclockwise spin of a planet or moon as seen from above the planet's north pole.
Retrograde Rotation
The clockwise revolution of a satellite around a planet or moon as seen from above the planet's or moon's north pole.
Gas Giants
The large, gaseous planets of the outer solar system.