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How many stars exist in the Solar System? |
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Which object below is not a member of the Solar System? |
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The Solar is system is about .... as old as the universe itself? |
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The nearest star to the planet Neptune is? |
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Planets are different from stars in that planets |
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are composed mostly of liquid and solid materials |
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the most massive object in the solar system is...? The object is a..? |
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What planet has a solid surface most affected by the greenhouse effect? |
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What planet does not appear to have a solid surface? |
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The diameter of the sun is approx... the diameter of the Earth? |
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How far does light travel in 10 seconds? |
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If the sun is reduced to the size of a ping pong ball (and all other sizes scaled down proportionately), then the distance to the Sun's nearest neighbor star is about? |
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A light year could also be expressed in terms of what other units? |
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What shape most closely resembles the shape of our Milky Way Galaxy? |
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The solar neighborhood is defined as? |
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The region of space in our Galaxy including the nearest few tens of thousands of stars |
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Which statement below about the motion of the solar system in the Galaxy is correct? |
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The solar system is moving around the center of the Galaxy in a nearly circular path |
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If the solar system is reduced in size such that the orbit of Neptune is about the diameter of a ping pong ball, then the diameter of the Milky Way galaxy would be about the size of? |
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The Milky way galaxy is part of what large system of material? |
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The Virgo cluster belongs to what larger system of material? |
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Which astronomical system of matter are listed below in order of increasing size? |
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Solar neighborhood, Milky way galaxy, local group, local supercluster |
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Imagine a sudden astronomical event (for example, a stellar explosion) that actually occurred about the time of the birth of Christ. If this event is observed in the present epoch (say, 2009), then we can conclude that the event occurred at a distance of about... from earth |
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If the entire history of the universe is collapsed into one year, about when did the solar system form? |
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As seen in lexington, the north celestial pole appears about where in the sky? |
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about 40 degrees above the north horizon point |
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Imagine a time exposure photograph of the sky in which each star left a trail. Each trail is an arc of about 90 degrees. In this case, the exposure time of the photograph is about |
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If the sky is represented as a sphere, what fraction of the sphere is above the horizon (in a flat location)? |
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the celestial sphere appears to rotate 360 degrees in |
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Suppose you observe that the South Celestial Pole is straight overhead. Where are you on Earth? |
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The city of Melbourne, Australia has latitude of 38* south. Where in the skies of Melbourne would you find the south celestial pole? |
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38* above the south point of the horizon |
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Where on Earth do both the north and south celestial poles lie on the horizon? |
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Which object below was not a "wondering star" identified by ancient astronomers? |
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From the perspective of ancient astronomers, an example of a "fixed" star is... an example of a "wandering" star is... |
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Proxima Centauri, The sun |
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The sun is seen in the constellation Libra in October and in Scorpia in November. Why the change? |
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The path traced out by the sun in the sky over the course of a full year is called the |
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The sun appears to move.. degrees... in 24 hours as a result of the Earths rotation |
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The sun appears to move... degrees... in 24 hours as a result of the earths orbital motion |
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Constellations of the zodiac (of astrological importance) are different from other constellations in the sky that zodiac constellations |
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The dates of the year associated with the sun signs of astrology are different now from what they were in ancient times. This change is the result of the |
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Wobbling of the Earths rotational axis |
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Owing to its annual apparent motion, about how long does the sun take to "move" from one constellation to the next? |
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As a traveler moves north in the northern hemisphere |
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The north celestial pole rises higher above the horizon |
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The angle of the north celestial pole above the horizon was known by ancient astronomers to change as a traveler moved north or south. This information was used by ancient astronomers to infer |
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that the earth is spherical |
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what astronomical phenomenon is caused by the shadow of the earth? |
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Imagine using eratosthenes method of estimating the size of the earth based upon two cities along a north-south line. Suppose the sun angle at high noon is 36 degrees different between two cities located 3000 units apart. In this case, the estimated diameter of the Earth is about.... units |
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Suppose eratosthenes had been mistaken about the distance between alexandria and seyene. In particular, suppose he mistakingly thought the two cities were twice as far as part as they actually are. in this case, his estimate of the diameter of the earth would have been |
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two times larger than the correct value |
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In modern times, the occasional retrograde motion of mars and other planets is explained by the fact that mars |
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moves more slowly in its orbit than earth |
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Approximately how often does the planet jupiter exhibit retrograde motion? |
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In ancient times, the retrograde motion of mars and other planets was explained by the fact that mars |
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moves on a small circle called an epicycle |
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According to the solar system model of ptolemy, which objects take exactly the same time to go around the earth as does the sun? |
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According to ptolemy, the ... is at the center of the solar system, and the.. is the closest celestial neighbor to the earth |
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in what period did copernicus publish his book describing a sun centered solar system? |
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An important (and physically correct) objection raised by the contemporaries of Copernicus regarding his model of the solar system was that |
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nearer stars should shift positions relative to more distant stars if the earth moved about the sun |
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Ptolemy's model of the solar system is a... model, while Copernicus's model is a...model |
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What was the significance of Galileo's observations of the satellites of Jupiter? |
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The observations established that some objects in the solar system do not orbit the earth |
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Why( according to the model of Copernicus) does Venus always appear close to the sun in the sky? |
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it is closer to the sun than the earth |
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Why were the phases of Venus not used as an argument against the solar system model of ptolemy prior to the time of galileo? |
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the phases of venus could not be observed prior to galileo |
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careful study of the phases of venus establishes that |
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what was the principal contribution of the tycho brahe to the copernican revolution? |
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he measured the positions of the planets relative to the background stars. |
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which scientists made use of the astronomical records kept by Brahe to infer important new information about the solar system? |
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What astronomical instruments did tycho brahe construct? |
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Instruments that allowed for very accurate measurements of the positions of planets relative to the background stars |
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What is the significance of Kepler's discovery regarding the shapes of planetary orbits? |
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they are not circles nor combinations of circles |
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the average distance between a planet and the sun is the.. of the planets orbit |
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according to kepler's 1st law, one focus of a planets orbit is the location of... while the other focus is the location of... |
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In general, an ellipse has.. special point(s) within it. These points lie.. |
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what is the significance of kepler's second law of planetary motion ("equal areas" law) |
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a given planet (earth) moves faster in its orbit when it is closer to the sun |
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the longest dimension across the orbit of the earth is |
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what is the significance of keplers third law of planetary motion? (p2=a3) |
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planets closer to the sun (mercury) take less time to orbit the sun than planets further from the sun( earth) |
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According to keplers 3rd law (p2=a3), which planet has the longest period? |
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Which example below illustrates uniform motion? |
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marathon runner moving along a straight path at a constant speed |
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which object is acted upon by no net force? |
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elevator moving down the elevator shaft at a constant speed |
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an appropriate unit of acceleration is.. an appropriate unit of force is... |
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meters per sec per sec, newtons |
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consider a train moving along a straight track at a constant speed. what can you conclude about this train? |
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the net force acting upon the train is zero |
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what controls on an automobile can create acceleration of the vehicle? |
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accelerator, brake and steering wheel |
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suppose an object is falling downward under the acceleration of the earths gravity. If it is moving at 90 m/s at one moment, how fast is it moving 5 seconds later? ( neglect air resistance) |
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consider the 4 forces acting upon a train. what force is directed vertically upward? |
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the force of the rail on the train |
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imagine the same force acting upon two objects, 1 and 2. Object 2 has twice the mass of object 1. in this case, the acceleration of object 2 will be.. as that of object 1 |
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Imagine that a force of.. newtons acts upon an object having a mass of... kilograms. For which case will the resulting acceleration be highest? |
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according to newtons 3rd law of motion, the force pushing you ahead as you dash off down a sidewalk is |
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the force of the sidewalk upon you |
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Suppose a force of 20 newtons is applied to a object having a mass of 4 kilograms. what is the acceleration? |
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Imagine an object moving in a circle at constant speed ( planet in a hypothetical circular orbit about the sun) in this case, we can conclude that |
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there is a net force acting on the object perpendicular to its motion |
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the weight of an object is defined as the... An appropriate unit for weight is the... |
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gravitational force acting upon the object, newton |
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your mass on the moon would be ... your mass on earth, your weight on the moon would be.. your weight on earth |
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what quantities determine the gravitational force between two objects? |
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masses, distance between their centers |
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"weightlessness" occurs for an object when it is |
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only subject to the gravitational force |
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a pound of bread on the moon would contain...as a pound of bread on earth |
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if the distance between two objects increases 3 times (with the masses remaining the same), the gravitational force between them will |
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the gravitational force that the earth exerts upon the sun is... the force that the sun exerts upon the earth |
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the acceleration a 10 kilogram object experiences when dropped is... the acceleration of a 1000 kilogram object |
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if the masses of two objects are each tripled (and all other conditions remain the same) the gravitational force between them will |
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which person experiences weightlessness? |
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olympic driver who has just left the spring board |
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approximately what day of the year in lexington has the greatest number of hours of sunlight? |
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approximately what day of the year in Sidney, Australia has the fewest number of hours of sunlight? |
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the earth is closest to the sun in early january each year. what is the significance of this fact to seasons on earth. |
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this fact has very little relevance to seasons on the earth |
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the spring equinox in Melbourne, Australia occurs on about what date? |
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On about what day in lexington would the Sun rise furthest south of east? |
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On about what say in Melbourne, Australia wold the sun be highest in the sky at high noon? |
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If the earths rotational axis were perpendicular to its orbit ( no tilt) then... |
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Polar regions on the Earth would experience about 12 hours of sunlight per day on any day of the year but still be colder than equatorial regions |
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Point Barrow, Alaska, is north of the Arctic Circle. About how many hours of sunlight does Point Barrow experience in late december? |
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How do celestial objects move in the sky (over 24 hours) as seen from the Earth's north pole? |
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They trace out circles around the sky at constant angles above the horizon |
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The cause of the season on earth is.. |
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The 23 1/2 degree tilt of the Earth's axis relative to its orbit |
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At the earths south pole, where will the sun be in late june? |
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about 23 degrees below the horizon |
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Shortly after the new moon, the phase of the moon is said to be |
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suppose the moon is new on about november 1. In this case, we expect the third quarter moon to be visible on about |
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At any given moment... of the surface of the moon is illuminated. This illuminated part of the Moons surface faces the... |
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What fraction of the illuminated surface of the moon faces the earth? |
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The answer is different depending upon the phase of the moon |
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What is the effect of the earths shadow upon lunar phases? |
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The shadow has no effect upon phases of the moon |
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If the moon sets at sunset, what is the phase of the moon? |
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Imagine that you observe a third quarter moon this evening in lexington. What phases of the moon would be observed at the same time in Santiago, Chile? |
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The sea of showers is a prominent dark region on the surface of the moon. This region always faces the earth, regardless of the position of the moon in its orbit about the earth. Why does the sea of showers always face the earth? |
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The moon rotates on its axis in the same time it revolves around the earth |
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Imagine living on the moon. How long would a full cycle of phases of the earth take to complete? |
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About how long is the sun above the horizon as seen on the far side of the moon. ( the side facing away from the earth?) |
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