Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Study Guide Astronomy Chapter 1
Document related concepts
Transcript
Study Guide Astronomy Chapter 1 Vocabulary Astronomy Leap year Celestial equator Reflecting telescope Calendar Constellation Ecliptic Year Altitude Light year Month Right ascension Telescope Electromagnetic spectrum Summer solstice Winter solstice Day Declination Refracting telescope equinox Calendars: Based on movements of objects in the sky Ancient civilizations developed calendars Mayans: based on cycles of moon, sun, and Venus Egyptians: calendar 12 thirty day months and one 5 day month Hebrew: based on moon and sun and had 12 or 13 months per year Chinese: based on moon’s phases Our modern calendar based on Roman calendar Gregorian calendar adjusted leap year correctly Ancient astronomical observations Nabta: stones line up with summer solstice Stonehenge: stones line up with winter and summer solstice sunrise Chinese: predict eclipses, name stars Greeks: philosophers tried to understand sky Aristotle explained phases of moon and earth is sphere Native Americans: Maya buildings aligned with celestial objects Used complex mathematics Arabs: astrolabe, algebra, number system Continued to develop astronomy as a science Early Astronomers: Ptolemy: earth centered “universe” (geocentric) called Ptolemaic Theory Copernicus: first to theorize sun (heliocentric) at center of “universe”: Copernican Theory Tycho Brahe: geocentric belief, first to bring instruments into astronomy Johannes Kepler: heoliocentric belief, laws of planetary motion Galileo Galilei: heliocentric belief, first telescope, saw features on moon Discovered sun spots and four of Jupiter’s moons Issac Newton: explained why planets orbit sun:GRAVITY Laws of motion Modern Astronomy: Technology improves, tools improve- knowledge increases Herschel: fuzzy patches not stars, discovered Uranus Hubble: fuzzy patches were galaxies; found expanding universe Constellations: Ancient people group stars into patterns Constellations break sky into 88 regions, like states in the U.S. Rotation, revolution and location determine what stars you will see in sky Circumpolar stars are seen all year round Circumpolar stars seem to rotate counter clockwise around a stationary North Star Locating stars: Very general location: in constellation Astrolabe used for finding stars at same location at same time Horizon: place where sky meets Earth Zenith: 90° above observer Altitude: angle between horizon and observer Precise location: Use right ascension: like longidute but hours past vernal equinox Use declination: degrees north or south of celestial equator; like latitude Size and Scale Measure distance in light years: distance light travels in one year Telescopes Look at universe using all of the electromagnetic : radio, infrared, visible, ultraviolet, x-ray, gamma Visible spectrum: use reflecting and refracting telescopes Other telescopes for other frequencies Put ultraviolet, x-ray, and gamma ray telescopes in orbit as our atmosphere blocks out most of these rays Linking radio telescopes makes them act as one larger more powerful telescope Light pollution, water vapor, and atmospheric interference on earth limits visible spectrum observation Place telescopes in space to avoid problems of visibility
