Intro to Astronomy Chapter 4 Conceptual Questions
What does Kepler's second law indicate about the orbital speed of a planet? A planet moves at its fastest when it is closest to the sun. The orbital speed of each planet is constant. A planet moves at its slowest when it is closest to the sun. The orbital speed of a planet varies in no predictable way. None of these choices are correct.
A planet moves at its fastest when it is closest to the sun.
Who taught that the Earth is stationary and at the center of the universe with the sun, the moon, and the planets moving around Earth in perfect circles? Aristotle (384-322 BC) Eratosthenes (c. 200 BC) Pythagoras (c. 570-500 BC) Eudoxus (409-356 BC) Thales of Miletus (c. 624-547 BC)
Aristotle (384-322 BC)
Why did Copernicus use epicycles in his system? It was the only way to explain retrograde motion. Actually, Copernicus did not use epicycles. Unlike the Ptolemaic system, all the planets were treated the same. Copernicus insisted on circular motions and needed epicycles to reproduce minor variations in motions of planets.
Copernicus insisted on circular motions and needed epicycles to reproduce minor variations in motions of planets.
How did Claudius Ptolemy account for the retrograde motion of the planets? Each planet moves on an epicycle that in turn moves on a deferent that circles around Earth. Planets slow down, stop, and then reverse their orbital direction around the sun. Inner planets orbit the sun faster and pass outer planets as they orbit around the sun. The sun and moon orbit Earth, whereas all the other planets orbit the sun. None of these choices are correct.
Each planet moves on an epicycle that in turn moves on a deferent that circles around Earth.
Which of the following scientists was condemned by the Catholic Church? Galileo Copernicus Kepler all three of these people
Galileo
How was Tycho Brahe able to make more accurate astronomical measurements than had been made before his time? He designed and used large devices to measure small angles. He used a telescope to magnify the image and spacing of celestial objects. His island observatory was hundreds of miles offshore under very dark skies. His observatory was at high elevation and thus above much of Earth's atmosphere. All of these choices are correct.
He designed and used large devices to measure small angles.
How did Nicolaus Copernicus account for the retrograde motion of the planets? Inner planets orbit the sun faster and pass outer planets as they orbit around the sun. Planets slow down, stop, and then reverse their orbital direction around the Earth. Each planet moves on an epicycle that in turn moves on a deferent that circles around Earth. The sun and moon orbit Earth, whereas all the other planets orbit the sun. None of these choices are correct.
Inner planets orbit the sun faster and pass outer planets as they orbit around the sun.
How did Kepler's first law of planetary motion alter the Copernican system? It added epicycles to the perfect circles and it placed the sun at one focus of each orbit. It changed the perfect circles to ellipses. It added epicycles to the perfect circles. It changed the perfect circles to ellipses and it placed the sun at one focus of each orbit. It placed the sun at one focus of each orbit.
It changed the perfect circles to ellipses and it placed the sun at one focus of each orbit.
In Tycho's model of the universe, the moon and the sun orbited Earth, and all the planets orbited the sun. Which of the following is true for the explanation of the phases of Venus in Tycho's system? It was the same as in the Ptolemaic system. It matched Galileo's telescopic observations. Actually, the Tychonic system had no explanation for the phases of Venus. It did not match Galileo's observations.
It matched Galileo's telescopic observations.
Galileo made several important telescopic discoveries. How did Galileo's telescopic discovery of craters on the moon contradict Ptolemaic theory? Actually, it did not contradict Ptolemaic theory. It showed that not everything orbited Earth. It was possible in Copernican theory, but not Ptolemaic theory. It showed that a heavenly body was not perfect.
It showed that a heavenly body was not perfect.
Planet Phases. If you lived on Mars, which planets would never be visible at crescent phases? ________. Mercury Venus Earth Jupiter Saturn Uranus Neptune
Jupiter Saturn Uranus Neptune
In Ptolemy's mathematical model of planetary motion, a planet was on a circular path, known as an epicycle, whose center was on another circular path, a deferent, that was centered on Earth. Which planets' motions were described with epicycles in the Ptolemaic system? Ptolemy's system did not use epicycles. Mars, Jupiter, and Saturn Mercury and Venus all of the known planets
all of the known planets
Evidence of early prehistoric human cultures observing astronomical phenomena exists in which of the following? oral traditions Actually, there is no evidence of early human cultures observing astronomical phenomena. archaeoastronomical sites written records
archaeoastronomical sites
Which of these two figures matches the phases of Venus observed by Galileo? He only observed Venus in its full phase. He only observed Venus in its first quarter phase. figure a (left) He could not see phases because his telescopes were not powerful enough. figure b (right)
figure b (right)
Newton's Second Law I. Two equal body masses are accelerated, but Body A's acceleration is half of Body B's. Is the force on Body A greater, less than, or equal to the force on Body B? greater than less than equal to
less than
Which set of astronomical tables is based on Ptolemy's model? the Prutenic tables the Rudolphine tables the Alfonsine tables None of these choices are correct
the Alfonsine tables
Which is not an archaeoastronomical site? the temple of Isis the island of Hveen Stonehenge Newgrange
the island of Hveen
Below is a postage stamp with a picture of a scientist holding an astronomical model. Which object is the central figure in the model? the moon the sun Earth All of these choices are correct.
the sun
If you lived on Mars, which planets would exhibit retrograde motion? Saturn Neptune Jupiter Uranus All of these choices are correct.
All of these choices are correct.
The diagram below shows a view of the eastern horizon (horizontal line --------) with the direct eastern horizon point labeled B. The direction to points northeast of the direct east point is labeled with an A and an arrow. The point southeast of the direct east point is labeled with a C and an arrow. A B C ------------------EAST------------------ For a mid-latitude northern hemisphere observer, what point corresponds to the rising point of the sun on the date of the autumnal equinox? B A C None of these are correct. The sun does not rise on that date.
B
Evidence of how the ancients described the placement of Earth is found partly through archaeostronomy, the study of the astronomy of ancient peoples, and through history beginning with the ancient Babylonians and Greeks. Based on ancient astronomy, select all of the correct statements from the following list. Classical philosophers believed that Earth did not move. Classical philosophers knew that many orbits were elliptical and not circular. Ptolemy changed the ancient belief in the geocentric system by suggesting that the sun was the center of the universe. Classical philosophers believed that Earth was the center of the universe. Ancient cultures left detailed written records of their astronomical beliefs. Aristotle argued that crystalline spheres of the geocentric system did not represent physical reality, but were just a scientific model. Eratosthenes accurately estimated the diameter of the Earth.
Classical philosophers believed that Earth did not move. Classical philosophers believed that Earth was the center of the universe. Eratosthenes accurately estimated the diameter of the Earth.
Below is a postage stamp with a picture of a scientist holding an astronomical model. Who developed this theoretical model? Copernicus Ptolemy Tycho None of these choices are correct.
Copernicus
Copernicus changed the place of Earth by devising a heliocentric model of the cosmos. Based Copernicus and the heliocentric system, select all of the correct statements from the following list. Venus and Mercury had to be handled differently than the other planets in Copernicus's heliocentric model. Copernicus's heliocentric model provided a simple explanation for retrograde motion. Copernicus's model featured multiple motions of Earth. Copernicus's heliocentric model predicted the positions of planets very well. Copernicus was condemned by the Church for his theory. Copernicus's theory agreed with Church teaching. Copernicus never published his work.
Copernicus's heliocentric model provided a simple explanation for retrograde motion. Copernicus's model featured multiple motions of Earth.
Which of the "First Principles of Ancient Astronomy" did Kepler's laws contradict? The heavens are perfect and Earth is imperfect. Earth is at the center of the universe and the heavens are perfect and Earth is imperfect. Earth is at the center of the universe. All heavenly motion is uniform and circular. Earth is at the center of the universe and all heavenly motion is uniform and circular.
Earth is at the center of the universe and all heavenly motion is uniform and circular.
Who accurately determined the size of Earth by considering sun angles at Syene and Alexandria? Pythagoras (c. 570-500 BC) Thales of Miletus (c. 624-547 BC) Aristotle (384-322 BC) Eudoxus (409-356 BC) Eratosthenes (c. 200 BC)
Eratosthenes (c. 200 BC)
Galileo made many observations about the heavens, and was also condemned by the Church. Based on his discoveries and the case against him, select all of the correct statements from the following list. Galileo observed craters on the moon and sunspots on the sun. Galileo's case has recently been reexamined by the Catholic Church. Galileo's trial was more about his disrespect of authority than his teachings of astronomy. Galileo invented the telescope. The observed phases of Venus supported the heliocentric system. The fact that Jupiter has moons suggested that Earth orbits the sun. Galileo was executed for saying that Earth orbits the sun.
Galileo observed craters on the moon and sunspots on the sun. Galileo's case has recently been reexamined by the Catholic Church. Galileo's trial was more about his disrespect of authority than his teachings of astronomy.
What effect did Plato's proposal have on future astronomers? His proposal had no effect, at least outside of his homeland, Greece. His idea of elliptical orbits was "rediscovered" by Kepler. His idea of a sphere being the most perfect geometric form influenced astronomical theories for literally hundreds of years. None at all; being a philosopher and not an astronomer, what he said was ignored.
His idea of a sphere being the most perfect geometric form influenced astronomical theories for literally hundreds of years.
In Tycho's model of the universe, the moon and the sun orbited Earth, and all the planets orbited the sun. Which of the following is true for the explanation of the phases of Venus in Tycho's model? It agrees with Galileo's telescopic observations, because Venus is at no time farther away from Earth than the sun. It does not agree with Galileo's telescopic observations, because Venus at times is farther away from Earth than the sun. It does not agree with Galileo's telescopic observations, because Venus is at no time farther away from Earth than the sun. It agrees with Galileo's telescopic observations, because Venus at times is farther away from Earth than the sun.
It agrees with Galileo's telescopic observations, because Venus at times is farther away from Earth than the sun.
Galileo made several important telescopic discoveries. How did Galileo's telescopic discovery of sunspots contradict Ptolemaic theory? It was possible in Copernican theory, but not Ptolemaic theory. It showed that not everything orbited Earth. Actually, it did not contradict Ptolemaic theory. It showed that a heavenly body was not perfect.
It showed that a heavenly body was not perfect.
Galileo made several important telescopic discoveries. How did Galileo's telescopic discovery of the moons of Jupiter contradict Ptolemaic theory? It showed that a heavenly body was not perfect. It showed that not everything orbited Earth. Actually, it did not contradict Ptolemaic theory. It was possible in Copernican theory, but not Ptolemaic theory.
It showed that not everything orbited Earth.
In 1572, Tycho observed a brilliant "new star," now called Tycho's supernova. What was a result of his failure to detect a parallax shift for this star? Actually, he did detect parallax, which convinced him that Earth moved and caused him to believe in the Copernican system. It made him certain that Earth did not move, affirming his belief in the Ptolemiac system. It made him decide that he needed to develop better observational techniques. It undermined his belief in the Ptolemaic system, because it meant that the star was far enough away to be part of the "fixed background" of stars, which should be unchanging.
It undermined his belief in the Ptolemaic system, because it meant that the star was far enough away to be part of the "fixed background" of stars, which should be unchanging.
Why did the model of the universe proposed by Copernicus gain support soon after its publication? It gave a better explanation for the phases of the moon. The old system of Ptolemy was never very popular. It more accurately predicted the position of the planets. It was a more elegant explanation of retrograde motion. It displaced Earth from the center of the universe.
It was a more elegant explanation of retrograde motion.
Galileo made several important telescopic discoveries. How did Galileo's telescopic discovery that Venus went through the same cycle of phases as the moon contradict Ptolemaic theory? It showed that a heavenly body was not perfect. It showed that not everything orbited Earth. Actually, it did not contradict Ptolemaic theory. It was possible in Copernican theory, but not Ptolemaic theory.
It was possible in Copernican theory, but not Ptolemaic theory.
Planet Retrograde Motion I. If you lived on Mars, which planets would describe retrograde loops? Mercury Venus Earth Jupiter Saturn Uranus Neptune
Jupiter Saturn Uranus Neptune
The 99 years between the deaths of Copernicus and Galileo saw the birth of science in its modern form. Select all of the correct statements from the following list. Kepler and Galileo were among the first to make scientific predictions based on data analysis and observation. Although important to historical astronomy, Tycho's observations were not important in the development of modern science. There had been many detailed observations made in many areas of science before that time. Modern science depends on evidence to test theories. Many fields were going through major changes at the time that astronomy and science in general were evolving to their modern forms. The scientific method was well-established prior to the time of Copernicus. The birth of modern astronomy was also really the birth of modern science. Mathematical analysis of data was a well-established process in science when Kepler began studying Tycho's data.
Kepler and Galileo were among the first to make scientific predictions based on data analysis and observation. Modern science depends on evidence to test theories. Many fields were going through major changes at the time that astronomy and science in general were evolving to their modern forms. The birth of modern astronomy was also really the birth of modern science.
Based on Tycho's observations and Kepler's discoveries regarding planetery motion, select all of the correct statements from the following list. Kepler found that the speed of a planet varied throughout its orbit. Prior to his analysis of the data, Kepler believed there should be a simple relationship between a planet's orbital period and its distance from the sun. Tycho made most of the observations used by Kepler. Kepler's analysis showed that sun was still in fact at the exact center of the planetary orbits. Kepler discovered that planetary orbits are elliptical, not circular. Kepler's laws of planetary motion more or less agreed with theories he had before he analyzed the data. Tycho and Kepler worked together on the analysis of Tycho's observations.
Kepler found that the speed of a planet varied throughout its orbit. Prior to his analysis of the data, Kepler believed there should be a simple relationship between a planet's orbital period and its distance from the sun. Tycho made most of the observations used by Kepler. Kepler discovered that planetary orbits are elliptical, not circular.
Galileo's discovery of four moons orbiting Jupiter showed that planetary bodies could move and carry moons. This supports the model of the universe presented by whom of the following? Nicolaus Copernicus Aristotle Claudius Ptolemy Aristotle and Claudius Ptolemy All of these choices are correct.
Nicolaus Copernicus
The phases of Venus observed by Galileo support the model of the universe presented by which of the following? Nicolaus Copernicus Aristotle Claudius Ptolemy Aristotle and Claudius Ptolemy All of these choices are correct.
Nicolaus Copernicus
Which represents an unchangeable truth? a natural law a hypothesis a theory None of these choices are correct.
None of these choices are correct.
In 1572, Tycho observed a brilliant "new star," now called Tycho's supernova. Which is true about Tycho's "Tychonic" system? All objects orbited Earth. It was verified by Kepler's analysis. Planets orbited the sun, which orbited Earth. All objects orbited the sun.
Planets orbited the sun, which orbited Earth.
Which list below has the life and work of the following scientists in chronological order, from left to right? Galileo, Tycho, Ptolemy, Copernicus Copernicus, Galileo, Tycho, Ptolemy Ptolemy, Copernicus, Tycho, Galileo Tycho, Ptolemy, Copernicus, Galileo
Ptolemy, Copernicus, Tycho, Galileo
Why is Stonehenge thought to be an ancient astronomical observatory? Petroglyphs at the site describe how they were used to make observations. Stones are aligned with significant rising and setting positions. Petroglyphs at the site describe how they were used to make observations and stones are aligned with significant rising and setting positions. All of these choices are correct. Ancient Greek writings list the important discoveries made at this site.
Stones are aligned with significant rising and setting positions.
Galileo's telescopes were not of high quality by modern standards. When Jupiter was closest to Earth, he was able to see its disk and moons, but he never reported seeing the disk or features on Mars. What is a good explanation for this difference? (Hints: Use the small-angle formula to find the angular diameter of Mars when it is closest to Earth. How does that compare with the maximum angular diameter of Jupiter? [Assume circular orbits with radii equal to the average distance from the sun.] At its closest, Jupiter is 4 AU from Earth and Mars is 0.5 AU from Earth. Jupiter is 0.000477 AU and Mars is 0.0000226 AU in diameter.) The angular size of Jupiter is smaller than the angular size of Mars. The angular size of Mars is smaller than the angular size of Jupiter. They both have the same angular size. Not enough information is given to say anything about their relative angular sizes.
The angular size of Mars is smaller than the angular size of Jupiter.
What did Plato propose about all heavenly motion? The motion is in elliptical paths. The motion is incomprehensible from Earth. The motion is in circular paths. Only shadows of the motion can be seen on Earth.
The motion is in circular paths.
The figure shown here illustrates how to draw an ellipse with two tacks and a loop of string. Imagine constructing a new ellipse using the same string but with the distance between the two pins reduced to zero. Which statement below is true? The semimajor axis of the new ellipse is longer than that of the original ellipse. The new ellipse is more elliptical than the original ellipse. The new ellipse is a circle. The new ellipse is actually a flat line. The new ellipse is more circular than the original ellipse without being a perfect circle.
The new ellipse is a circle.
The figure shown here illustrates how to draw an ellipse with two tacks and a loop of string. Imagine constructing a second ellipse using the same string but with the distance between the two tacks increased by 10%. How does this second ellipse compare to the original ellipse shown here? We cannot tell without more information. The second ellipse is more nearly circular than the original ellipse. The second ellipse is larger than the first but is not more circular or more elliptical (it has the same shape). The semimajor axis of the second ellipse is shorter than that of the original ellipse. The second ellipse is more elliptical than the original ellipse.
The second ellipse is more elliptical than the original eclipse.
In Ptolemy's mathematical model of planetary motion, a planet was on a circular path, known as an epicycle, whose center was on another circular path, a deferent, that was centered on Earth. How did the epicycles of Mercury and Venus differ from those of Mars, Jupiter, and Saturn? They were centered on the sun, not Earth. Actually, Mercury and Venus did not have epicycles. Their centers had to always be on the line between Earth and the sun. They moved in opposite directions to the other planets.
Their centers had to always be on the line between Earth and the sun.
In Tycho's model of the universe, the moon and the sun orbited Earth, and all the planets orbited the sun. In Tycho's model, the phases of Venus were which of the following? They were the same as in the Ptolemaic model. They were the same as in the Copernican model. They were different than either those in the Ptolemaic or Copernican model. They were not explained.
They were the same as in the Copernican model.
In Tycho's model of the universe, the moon and the sun orbited Earth, and all the planets orbited the sun. Which of the following is true for Galileo's telescopic observation of the phases of Venus? They were the same as the explanation in Tycho's model only. They were the same as the explanation in the Ptolemaic model only. They were the same as the explanation in the Copernican model only. They were the same as the explanation in two of these models.
They were the same as the explanation in two of these models.
When Tycho observed the new star of 1572, he could detect no parallax. Why did that result undermine belief in the Ptolemaic system? This star is closer than the moon and thus stars are not all at the same distance. This star is farther away than the moon and thus the heavens are not perfect and unchanging. This star is farther away than the moon and thus the heavens are perfect and unchanging. This star is closer than the moon and thus smaller than other stars. This star is planet-like.
This star is farther away than the moon and thus the heavens are not perfect and unchanging.
Whose observatory is shown in the figure below? Kepler's Tycho's Copernicus's Galileo's
Tycho's
If you lived on Mars, which planet would be visible as a crescent phase? Saturn Jupiter Mars Uranus Venus
Venus
Below is a postage stamp with a picture of a scientist holding an astronomical model. What is the larger circle in his model? a deferent Either an epicycle or a deferent, depending on which planet they are for. an epicycle None of these choices are correct.
a deferent
Which is an assertion or conjecture that must be tested? a natural law a theory a hypothesis None of these choices are correct.
a hypothesis
Galileo's telescope showed him that Venus has a large angular diameter of 61 seconds of arc when it is a crescent; a small angular diameter of 10 seconds of arc when it is nearly full and, finally, when Venus is "half full," an angular size of 59 seconds of arc. At which point described below is Venus closest to the Earth? a large angular diameter of 61 seconds of arc when it is a crescent a small angular diameter of 10 seconds of arc when it is nearly full "half full," with its angular size of about 59 seconds of arc
a large angular diameter of 61 seconds of arc when it is a crescent
Which is a theory that has been refined, tested, and confirmed so often that scientists have great confidence in it? a theory a natural law a hypothesis None of these choices are correct.
a natural law
The quantitative numerical result of Kepler's research was a set of tables giving future positions of the planets. a set of tables giving future positions of the continents. a set of tables giving past positions of the planets. a set of places where space telescopes looked.
a set of tables giving future positions of the planets.
Which is a system of rules and principles that can be applied to a wide variety of circumstances? a hypothesis a theory a natural law None of these choices are correct.
a theory
Below is a postage stamp with a picture of a scientist holding an astronomical model. What is the smaller circle in his model? a deferent an epicycle Either an epicycle or a deferent, depending on which planet they are for. None of these choices are correct.
an epicycle
The diagram below shows a view of the eastern horizon (horizontal line --------) with the direct eastern horizon point labeled B. The direction to points northeast of the direct east point is labeled with an A and an arrow. The point southeast of the direct east point is labeled with a C and an arrow. A B C ------------------EAST------------------ For a mid-latitude northern hemisphere observer, what point corresponds to the rising point of the sun on the date of the vernal equinox? A C B None of these are correct. The sun does not rise on that date.
b
Kepler's Second Law, Orbital Velocity I. In the figure below, Kepler's second law is depicted. A planet moves from A'→B' in one month and from A→B in one month. Path A to B is longer than path A'→B'. Using this information, along which path is the planet traveling faster? a. A'→B' b. A→B
b. A→B
Why did Plato propose what he did about heavenly motion and the shape of heavenly objects? because of his telescopic observations because he believed the sphere to be the most perfect geometrical form because Earth seems to be a disk around us, and the sky appears to be a spherical shell above us because of the shape of the sun and the moon
because he believed the sphere to be the most perfect geometrical form
Why didn't Copernicus's system predict the positions of planets any better than Ptolemy's? because he didn't use epicycles Actually, the Copernican system predicted planetary positions better than the Ptolemaic system. because he used circular orbits because he ignored retrograde motion
because he used circular orbits
In Ptolemy's mathematical model of planetary motion, a planet was on a circular path, known as an epicycle, whose center was on another circular path, a deferent, that was centered on Earth. Why did the centers of the epicycles of Mercury and Venus have to remain on the line between Earth and the sun? because they moved in opposite directions to the other planets because they were never seen very far from the sun in the sky because, unlike the other planets, they were considered to orbit the sun because they were closer to Earth than the other planets
because they were never seen very far from the sun in the sky
Plato proposed that all heavenly motion is which of the following? circular both circular and uniform uniform constantly changing constantly changing and circular
both circular and uniform
Galileo's telescope showed him that Venus has a large angular diameter (61 seconds of arc) when it is a crescent and a small angular diameter (10 seconds of arc) when it is nearly full. When Venus is "half full," its angular size is about 59 seconds of arc. This sequence of phases and angular sizes indicates that Venus: stays a fixed distance from the Earth always closer than the sun. circles the Earth staying a fixed distance closer to the Earth than the sun. stays a fixed distance from the Earth, always farther than the sun. circles the sun.
circles the sun
Gravitational Force, Body A, B I. Body A has the same mass as Body B and is located a distance d from Body B. If Body A is moved further away from Body B by twice as much, did the gravitational force increase, decrease, or stay the same? increase decrease stay the same
decrease
Gravitational Force, Body A, B, C I. If Body A is twice as massive as Body B and both bodies are at the same distance from Body C, is the force of gravity between Body A and Body C greater than, less than, or equal to the force of gravity between Body B and Body C? greater than less than equal to
greater than
What phases of Venus are predicted by the Ptolemaic system? quarter and gibbous phases only crescent and gibbous phases only new, crescent, quarter, gibbous, and full phases gibbous and full phases only new and crescent phases only
new and crescent phases only
What phases of Venus were observed by Galileo? crescent and gibbous phases only gibbous and full phases only new, crescent, quarter, gibbous, and full phases new and crescent phases only quarter and gibbous phases only
new, crescent, quarter, gibbous, and full phases
Which set of astronomical tables is based on the Copernican model? the Alfonsine tables the Rudolphine tables the Prutenic tables None of these choices are correct.
the Prutenic tables
Which set of astronomical tables was developed most recently? the Prutenic tables the Alfonsine tables the Rudolphine tables None of these choices are correct.
the Rudolphine tables
Which set of astronomical tables were considered most accurate? the Prutenic tables the Rudolphine tables the Alfonsine tables None of these choices are correct.
the Rudolphine tables
Which set of astronomical tables were worked on by Tycho and Kepler? the Prutenic tables the Alfonsine tables the Rudolphine tables None of these choices are correct.
the Rudolphine tables
One of the first principles of ancient astronomy is that the heavens beyond _____ are perfect, and the Earth is corrupt. the atmosphere Pluto the sun Saturn the moon
the moon
In Ptolemy's mathematical model of planetary motion, a planet was on a circular path, known as an epicycle, whose center was on another circular path, a deferent, that was centered on Earth. What were epicycles used to describe? the retrograde motion of planets a planet's motion around the sun a planet's motion around Earth the prograde motion of planets
the retrograde motion of planets
What was the most important contribution of Tycho Brahe to modern astronomy? the invention of the optical telescope the study of the Supernova of 1572 a model of the universe that was part Aristotelian and part Copernican twenty years of accurate measurements of planetary positions the discovery of four moons orbiting Jupiter
twenty years of accurate measurements of planetary positions
What feature of Aristotle's model of the universe was included in the model proposed by Copernicus? uniform circular motion Mars, Jupiter, and Saturn move around Earth. Earth is stationary and at the center. Mercury and Venus move around the sun. elliptical orbits
uniform circular motion
