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Cards In This Set
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Describe the geocentric model of planetary motion.
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- The Greek philosopher Aristotle proposed this model 2000 years ago
- Earth is at the centre, surrounded by cencentric spheres represtenting the paths of the Sun, Moon, and five plantets - distant stars did not move as they were attached firmly to the outermost sphere (celestial sphere) |
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What did the geocentric model allow early atronomers to forecast?
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Phases of the Moon
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Which five planets were known in Aristotle's time?
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Mars, Jupiter, Venus, Saturn and Mercury
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Describe the heleocentric model of planetary motion.
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- proposed by Polish atronomer Nicholas Copernicus in 1530
- suggested the Sun was at the centre and Earth and other planets revolved in orbits around it.
- could not predict planetary motion very accurately.
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Who confirmed Copernicus' theory?
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With the invention of the telescope in the 1600's, Galileo Galilei confirmed the heleocentric model.
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What was missing from Copernicus' theory?
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- Danish astronomer, Tyco Brahe studied and recorded the movement of the planets.
- German mathematician, Johannes Kepler realized the orbits were ellipses and not circles. |
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Define solstice.
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either of two times in the year when the Sun reaches its highest or lowest point in the sky at noon; in the northern hemisphere, the summer solstice occurs near June 21 (longest day of the year) and the winter solstice occurs near December 21 (shortest day)
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What does Stonehenge have to do with the solstice?
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- over 3500 years ago, megaliths were erected in southern England.
- stones are set in a circle to observe the rising and setting of the Sun and Moon. - knowledge of arrival of solstice helped agicultural communities know when to plant and harvest crops. |
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Define equinox.
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either of the two times a year (once in spring and once in autumn) when the Sun crosses the equator and day and night are of equal length; usually on or about March 21 and September 23
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Describe the Mayan views on the equinox.
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The Mayans of Central America built an enormous cylinder shaped tower, at Chichen Itza, to celebrate the two equinoxes (about 1000 A.D.)
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How was the quadrant used in space exploration?
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About the 2nd century A.D., the Egyptian astronomers designed a tool called a quadrant to measure a star’s height above the horizon.
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What is the astrolabe?
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An astrolabe is a device used to measure the altitude of an object. It was used by the Arabian astronomers for centuries to make accurate charts of star positions.
- With this device, astronomers and others could predict when the sun and certain bright stars would rise or set on any given day. - Ipparch invented the astrolabe in the 2nd century B.C. |
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Describe the telescope.
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- was invented in 1608 by Hans Lippershey to magnify images.
- Galileo Galilei improved the telescope to view celestial bodies. - revolutionized astronomy - could see details of Earth's closest planetary neighbours - showed existence of other neighbours in our solar system. |
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What is a space telescope?
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- super-powerful optical and radio telescopes operating from Earth and satllites
- shows us the immensity of objects in space and of distances across the universe - examples: Hubbles Space Telescope, James Webb Space Telescope |
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What are space probes?
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unmanned satellites or remotecontrolled “landers” used to explore areas or objects in space that are too difficult or dangerous to send humans to
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