Test 1 Study Guide PDF

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Test 1 Study Guide...

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Study Questions for Test 1 Chapter 1: What is Scientific Notation? an easy way to write big or small numbers. What is an Astronomical Unit? an AU is the average distance from the Earth to the Sun. What is a Light-Year? a LY is the distance light travels in one year. What is meant by the term “Look Back Time? the time elapsed between when we detect the light here on Earth and when it was originally emitted by the source. What objects comprise the Solar System? a single star (our sun) and the eight planets Define the following terms Star – Planet – Moon – Asteroid – Comet – Kuiper Belt What is a galaxy? a cluster containing lots of gas, dust, and stars. What is the Local Group? another name for our galaxy, and about two dozen nearby galaxies What is the Virgo Supercluster? what our local group is organized into. What is the name of the nearest large galaxy? Andromeda Chapter 2: How many constellations are there? 88 today How are stars designated according to brightness within a constellation? As a star’s magnitude increases from +1 to +6, its apparent brightness in the sky decreases. What is parallax? Why was it relevant to the early Greeks? the apparent change in the position of an object due to a change in the location of the observer.

What sort of popular names do the 50 brightest stars in the sky have? red giants Where is the star Polaris always located in N Hemisphere skies? towards the North What is the magnitude scale? What is meant by apparent visual magnitude? used to measure the brightest stars. We can increase our ability to do so by using a telescope that up the magnitude of our skies. What is the North Celestial Pole? Polaris, The North Star What is the celestial equator? What is the zenith? the extension of earth's equator on the celestial sphere. It divides this celestial sphere into the North and South hemispheres. the overhead part of the sky. What is the Ecliptic? the pathway of the sun against the background of the stars. The plane of earth's orbit around the sun. What is Precession? the gradual tilt of our earth on its axis. This occurs every 26,000 years. What effects do the rotation, revolution and precession of Earth have on the apparent motions of celestial objects in the sky?

What was the classical Greek conception of the Universe? that the universe revolves around earth, not the other way around. What were the most significant contributions of each of the following people? Aristarchus, Eratosthenes, Ptolemy, Copernicus, Galileo Brahe, Kepler and Newton 1. Aristarchus: argued that the earth revolved around the sun. Claimed that astronomers underestimated the distance of the stars away from earth, therefore we didn't experience any noticeable parallax. 2. Eratosthenes: measured the size of the earth. He took the angle and axis of the sun’s shadow inside a well, and compared it to a well in another city a bit further away. He was able to estimate the diameter of the earth with these measurements. 3. Ptolemy: he believed that the earth was the center of the universe. Created the geocentric concept. 4. Copernicus: he believed that the planets and celestial objects orbited around the sun. Created the heliocentric concept.

5. Galileo Brahe: created and used his telescope to discover the moons of jupiter. This further supported the heliocentric beliefs. 6. Kepler: developed the three laws of planetary motion. 7. Newton: formulated the laws of motion and universal gravity. What was the Ptolemaic Model of the Universe? What devices did it incorporate? geocentric model, where all celestial objects revolved around the earth. How did Galileo’s observations of the Moon contradict the prevalent Greek view of the Universe? What did his observations of the phases of Venus indicate?

Chapter 3: What are Newton's Three Laws of Motion? Law of Ellipses: planets orbit the sun not in circles but as one of its centers of focus, Equal Area: the straight line joining a planet and the sun sweeps out in equal areas of space in equal intervals of time, and Periods: the distance of a planet from the sun is based off how long it takes for that planet to go around it. . What is Isaac Newton’s Law of Universal Gravitation? F=GMm/r2: the gravitational pull (F) between two objects is equal to the gravitational constant (G) times the product of their masses (M), divided by the square of the distance between them (r2). Chapter 4: What causes the seasons on Earth? How are seasons in N and S hemisphere related? seasons are not caused by the earth’s distance from the sun, but by the tilt of the earth’s axis. The seasons on either hemisphere will be opposite from each other. Define: Summer Solstice - Autumnal Equinox - Winter Solstice - Vernal Equinox 1. Summer Solstice: the time when the North Pole of earth points most directly to the sun. 2. Autumnal Equinox: when the polar axis of earth is midway between the extremes reached at the solstices. 3. Winter Solstice: the time when the North Pole of earth points most directly away from the sun. 4. Venal Equinox: “when the polar axis of earth is midway between the extremes reached at the solstices.” What are the Sidereal and Synodic Periods of the Moon? Sidereal Period states that the moon travels around the earth once every 27 ⅓ days. Synodic Period states that the moon appears through phases every 29 ½ days. What are the four named phases of the Moon? What is the Earth-Moon-Sun configuration for each? 1. new moon (no moon) 2. first quarter (half moon) 3. full (full) 4. third quarter (half)

What are spring tides? What are neap tides? How many tides does a coastal location experience daily? 1. spring tides are the highest and lowest tides that occur at the times of full and new moons 2. neap tides are the highest and lowest tide that occur at the times of first and last quarters 3. there are two high and two low tides everyday What are the conditions required for a solar and a lunar eclipse? when the moon is at its new phase and at one of the nodes in its orbit What is visible during a total lunar and a total solar eclipse? Lunar: the moon doesn’t disappear, but rather turns a luminous red color. They are always visible over large areas of the earth and for periods of several hours. Solar: the sky darkens to a deep twilight, and planets begin to come into view. Corona, Chromosphere, and Prominences appear around the sun, along with “baily’s beads” (a diamond ring) that may be seen....