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52 Cards in this Set

  • Front
  • Back
In the ________________ model, Earth is the center of the universe.
Geocentric. The ancient Greeks believed in a Geocentric model where all of the planets and stars revolved around the earth.
The Geocentric Model was the accepted theory for ______ years.
1500. The Earth-centered model proposed by Ptolemy was not seriously threatened until Copernicus.
The __________ model reversed its predecessor and placed the sun in the center of the universe.
Heliocentric. The Heliocentric, or Copernican, model places Earth and the other planets in orbit around the sun. This idea was first proposed by Aristarchus, who believed both sun and stars were fixed.
________ believed the universe was made of crystal spheres.
Aristotle. The Aristotilian view of the universe as a series of finite, interlocking spheres influenced thinking about astronomy for generations.
Ptolemy believed the planets ____________ Earth.
Orbited. While the Ptolemic model of the universe has Earth as its center, Ptolemy advanced the idea that planets moved along "little circles within bigger circles."
_______ is the founder of modern astronomy.
Copernicus. Nicolaus Copernicus revolutionized astronomy with his Heliocentric Model of the universe.
________ noted that the stars remained in fixed positions, relative to Earth.
Copernicus. This observation led to his sun-centered model of the universe.
Copernicus believed planets orbited in ____________.
Perfect circles. Because planets actually move along elliptical routes (and because the sun is not the center of the universe), Copernicus' model was inaccurate.
_________ first used a telescope to study the sky.
Galileo. Galileo Galilei found evidence of the Copernican or Heliocentric model when he pointed his telescope at the heavens.
_____________ is the father of modern observational astronomy.
Galileo. In 1609, Galileo first used his telescope to study the stars and planets.
Galileo claimed to have seen __ moons orbiting Jupiter.
Four. Galileo also recorded images of mountains on the Moon, moon-like phases on Venus, and some of the stars that make up the Milky Way.
Galileo's observations of _________ supported the Heliocentric model.
Venus. Galileo's observations of the phases of Venus proved that it orbited the Sun, not Earth.
_____ proved that the Milky Way was made of "tiny stars."
Galileo. His telescopic observations showed that the Milky Way was a galaxy of stars, not a nebulous dust cloud, as previously assumed.
_____ discovered Jupiter's moons.
Galileo. He observed four moons orbiting Jupiter: Callisto, Europa, Io, and Ganymede.
_______ developed new Laws of Planetary Motion.
Kepler. Johannes Kepler discovered that planetary orbits are elliptical.
Kepler's Laws are based on observations made by __________.
Tycho. Tycho Brahe, Kepler's mentor, made many accurate astronomical observations that later formed the basis of Kepler's work.
Tycho Brahe used a ___________ to measure the positions of planets and stars.
Mural quadrant. Quadrants were wedge-shaped devices commonly used in navigation; Tycho used the principle of the navigational quadrant to affix a large, ninety-degree arc to the wall of his observatory.
In 1577, Tycho showed that _______ were not part of Earth's atmosphere.
Comets. Tycho used the parallax effect to show that comets were outside Earth's atmosphere.
Kepler formulated ____ laws of planetary motion.
Three. Kepler's Three Laws of Planetary Motion state that planets orbit on ellipses around the Sun, a planet's orbital speed depends on where it is in its ellipse, and the length of time a planet takes to orbit the sun is proportional to the size of its ellipse.
According to Kepler, planets orbit the sun in _______ patterns.
Elliptical. Kepler's First Law of Planetary Motion states that the paths of motion of the planets are ellipses, with the Sun at one focus.
Kepler believed that a planet moves _______ when it is furthest from the Sun.
Slowest. Kepler's Second Law states that, as a planet moves along its ellipse, its speed changes, so it is moving slowest at the furtherst point in its orbit and fastest when nearest the Sun.
Kepler's Third Law concerns how long it takes a planet to _________ an orbit.
Complete. Kepler's Third Law states that the length of time it takes a planet to move around its orbit is related to the size of the ellipse.
______ discovered four moons orbiting Saturn.
Cassini. Giovanni Domenico Cassini was the first to observe the Saturnian moons Dione, Rhea, Lapetus, and Tethys and the gap in Saturn's rings.
______ discovered the Laws of Motion.
Newton. Sir Isaac Newton concluded that motion, inertia, and gravity were the fundamental phsyical forces of the universe.
Newtonian physics holds that ______ and inertia keep the planets in orbit.
Gravity. Newton explained that the planets and moon stay in orbit due to gravity.
________ predicted the discovery of Neptune.
Adams. John Couch Adams predicted the position of a planetary mass beyond Uranus. Because he failed to publish his findings, the discovery of Neptune is credited to Johann Gottfried Galle.
According to Arago, rotation may produce ________.
Magnetism. Dominique Francois Jean Arago is credited with this discovery.
_______ is credited with the discovery of Neptune.
Galle. Gottfried Galle and Heinrich Louis d'Arrest compared their observations to a star chart to identify Neptune.
__________ exclaimed, "That star is not on the map!"
d'Arrest. By saying this, d'Arrest alerted Galle to their discovery of Neptune.
Jupiter's satellite Amalthea was discovered by _________.
Barnard. Edward Emerson Barnard discovered this Jupiterean satellite and Barnard's Star, the second-closest star system to our Sun.
The first director of the Harvard College Observatory was ________.
Bond. William Cranch Bond studied Saturn with William Lassell during his tenure.
_______, one of Saturn's moons, was discovered by Bond and Lassell.
____________ founded the Yerkes, Palomar, and Mt. Wilson Observatories.
Hale. George Elley Hale founded these observatories.
The __________ Sky Survey became the backbone of modern observation astronomy in 1957.
Palomar. The National Georgraphic Society and the Palomar Observatory conducted this survey from 1950 to 1957.
_____ discovered Mars' moons.
Hall. Asaph Hall discovered Phobos and Deimos, the moons of Mars.
_______ accurately predicted the reappearance of the comet that bears his name.
Halley. Edmond Halley used Newton's laws and historical comet data to accurately predict the reappearance of what is now called Halley's Comet.
_________ believed that galaxies are "island universes."
Hubble. Edwin Powell Hubble also discovered a linear relationship between a galaxy's distance and speed with which it is moving. The Hubble Space Telescope is named in his honor.
_________ Law makes it possible to estimate the speed at which the universe is expanding.
Hubble's Law. This law is also used to estimate the age of the universe.
The nature of Saturn's rings was first described in ______.
1655. Christiaan Huygens accurately observed that Saturn was surrounded by rings and not two planets, as Galileo thought. Huygens also discovered Saturn's moon, Titan.
________ is known for his study of the lunar surface.
Kuiper. Gerard Kuiper studied the surface of the moon extensively. He also discovered Miranda and Nerid and found atmosphere on Titan.
__________ named Jupiter's moons.
Marius. Simon Marius discovered Jupiter's moons in 1610, around the same time as Galileo.
Simon Marius was the first to observe the ______ Nebula with a telescope.
Andromeda. Marius was also one of the first to observe sunspots.
_______ discovered "canals" on Mars.
Schiaparelli. He actually observed "channels," but a later mistranslation recorded this discovery as "canals."
According to __________, the canals of Mars proved there was intelligent life on that planet.
Lowell. Percival Lowell studied Mars at his Arizona observatory in 1894.
The first _______ of Mars overturned Lowell's theory Martian canal-building.
Photographs. William Henry Pickering produced these important photographs.
William Thomson developed the _______ scale.
Kelvin. On Thomson's Kelvin scale, the freezing point of water (0 C) is 273 K. The boiling point of water is 373 K.
The cloud of comet-like material around the sun is called the ______ cloud.
Oort. This cloud was named for Jan Hendrick Oort.
__________ discovered Uranus in 1781.
Herschel. Sir William Herschel spent his career cataloguing the heavens. He catalogued over 800 double stars and 2,500 nebulae.
In 1930, _________ discovered Pluto.
Tombaugh. Clyde Tombaugh discovered Pluto at the Lowell Observatory in Arizona.
________ invented the first telescope.
Lippershey. Galileo developed his telescope from written accounts of Hans Lippershey's invention.
Earth is surrounded by particles in the _____________.
Van Allen Belts. These radiation belts, discovered by James Van Allen, are held in place by Earth's magnetic field. Some reasearches have associated the belts with the polar aurorae.
The invention of __________ in the 1820s allowed astronomers to inmprove their observations of the sky.
Photography. This development led to the use of photographic plates in telescopic observations.