Chapter 1 Book Notes

Chapter 1 Book Notes - Astronomy 180 Chapter 1: Discovering...

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Astronomy 180 Chapter 1: Discovering the Night Sky (Pages 4-34) As we look farther and farther out into the universe, we also see farther and farther back into time Astronomers organize the night sky to help them locate objects in it The Earth’s spin on its axis causes day and night The tilt of the Earth’s axis of rotation and the Earth’s motion around the Sun combine to create the seasons The Moon’s orbit around the Earth creates the phases of the Moon and lunar and solar eclipses I. Scales of the Universe: Astronomical distances are, well, astronomical Everyday life: millimeters to thousands of kilometers (the metric system is standard in science) Astronomy: particles as small as a millionth of a billionth of a meter and systems of stars as large as a thousand billion billion kilometers across Scientific notation – “powers of ten” used to deal with numbers much larger or smaller than 1 (speeds ex: light) Astronomy-related objects have such a wide range of sizes, so astronomy takes from other fields of science, as well Understand what atoms are composed of and how they work; the nature and properties of light; the response of matter and energy to the force of gravity; the creation of energy by fusing particles together in stars; the ability of carbon alone to serve as the foundation of life… Stars by millions, billions, or trillions are held together by gravity = galaxies Black holes: regions of dense matter that cannot radiate light Astronomy is constantly changing! II. Patterns of Stars: Constellations make locating stars easy The unaided eye can only detect about 6000 stars…3000 in one hemisphere Location (orientation) can be derived using easily recognized constellations (Big Dipper = north) Polaris = North Star Regulus = brightest star in Leo “Arc to Arcturus and speed on to Spica” winter in the n. hemisphere = some of the brightest stars in the sky (“ ) Sirius = the brightest star in the night sky “Summer triangle” - Vega (Lyra - Lyre), Deneb (Cygnus - Swan), Altair (Aquila - Eagle) (mid-summer @ midnight) III. Patterns of Stars: The celestial sphere aids in navigating the sky Celestial sphere – a hypothetical sphere of very large radius centered on the observer; the apparent sphere of the night sky Constellation – an entire region of the sky and all the objects in that region (88 regions total) Asterisms – traditional star patterns that are not official constellations (Big Dipper)
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Chapter 1 Book Notes - Astronomy 180 Chapter 1: Discovering...

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