Earth Sci | 1Q Flashcards
(91 cards)
Ptolemy created a model of the universe that accounted for the movement of the planets.
Ptolemaic System
the apparent westward motion of the planets with respect to the stars
Retrograde motion
He concluded that Earth is a planet
Nicolaus Copernicus
designed and built instruments to measure the locations of the heavenly bodies
Tycho Brahe
He discovered three laws of planetary motion
Johannes Kepler
an oval-shaped path
ellipse
the average distance between Earth and the sun; it is about 150 million kilometers
astronomical unit (AU)
His most important contributions were his descriptions of the behavior of moving objects
Galileo Galilei
Although others had theorized the existence of gravitational force, Newton was the first to formulate and test the law of universal gravitation
Sir Isaac Newton
Gravitational force decreases with distance
universal gravitation
The two main motions of Earth are..
rotation and revolution
a third and very slow motion of Earth’s axis
Precession
the turning, or spinning, of a body on its axis.
Rotation
Two measurements for rotation:
Mean solar day
Sidereal day
the motion of a body, such as a planet or moon, along a path around some point in space
Revolution
the time in January when Earth is closest to the sun
Perihelion
is the time in July when Earth is farthest from the sun
Aphelion
is the time interval from one noon to the next, about 24 hours
Mean solar day
is the time it takes for Earth to make one complete rotation (360º) with respect to a star other than the sun—23 hours, 56 minutes, 4 seconds
Sidereal day
traces out a cone over a period of 26,000 years
Precession
the point at which the moon is closest to Earth
Perigee
the point at which the moon is farthest from Earth
Apogee
occur when the moon moves in a line directly between Earth and the sun, casting a shadow on Earth
Solar eclipses
occur when the moon passes through Earth’s shadow.
Lunar eclipses