Astronomy Final Exam pt. 1

Which of the following temperatures is closest to what you might expect on the planet Jupiter? a. -150F. b. 100F. c. -250F. d. -350F. e. 50F.

c. -250F.

Uranus rotates on its axis once in about a. 24 hours. b. 88 Earth days. c. 17 hours. d. 10 hours. e. 10 Earth days.

c. 17 hours.

Relative to the distant stars, Venus a. completes 1.5 rotations each time it orbits the Sun. b. does not rotate at all. c. completes less than one full rotation each time it orbits the Sun. d. completes 2 rotations each time it orbits the Sun. e. completes just one full rotation each time it orbits the Sun.

c. completes less than one full rotation each time it orbits the Sun.

The angle between the rotation axis of a planet and the perpendicular to the plane of its orbit is called its ìaxial tilt.îThe axial tilt of Mercury is a. 0.01 degrees. b. 25.2 degrees. c. 23.5 degrees d. 0.0 degrees. e. 93 degrees.

a. 0.01 degrees.

There are 365.242199 solar days in a year. From this fact, you can conclude that, relative to the distant stars, earth rotates closest to a. 366.242199 times in a year. b. 364.242199 times in a year. c. 365.242199 times in a year. d. a number of times in a year that cannot be determined from the information given.

a. 366.242199 times in a year.

You are looking down on the Earth from a spacecraft hovering far above. After watching for a while, you notice that, from your perspective, it is rotating clockwise. The part of the Earth that is directly below you must be the Earthís a. South Pole. b. North Pole. c. Equator.

a. South Pole.

A rocket that leaves the Earthís atmosphere at a speed of 8 miles per second will a. escape from the Earthís gravity forever. b. follow an elliptical path that is partly below the surface of the Earth. c. go into a circular orbit above the surface of the Earth.

a. escape from the Earthís gravity forever.

The magnetic field of Mars is a. essential zero b. similar in intensity to the Earth's magnetic field c. about 100 times the intensity of Earth's d. about 1% of the earth's magnetic field

a. essentially zero.

According to our current model of how planets form magnetic Öelds, the magnetic Öeld of Saturn is much less than the magnetic Öeld of Jupiter because Saturn a. has less metallic hydrogen in its core than Jupiter. b. has less liquid iron in its core than Jupiter. c. rotates more rapidly than Jupiter. d. has less ammonia-water mixture in its core than Jupiter. e. rotates more slowly than Jupiter.

a. has less metallic hydrogen in its core than Jupiter.

The presence of frozen water on Venus is a. impossible because every part of it is too hot for water ice. b. possible because the planet always keeps the same side turned directly away from the Sun. c. impossible because the night side, where it is cold, eventually rotates to face the Sun. d. possible because it has almost no axial tilt so that its poles never directly face the Sun.

a. impossible because every part of it is too hot for water ice.

The heat that reaches the surface of Saturn comes mostly from a. the interior of Saturn. b. solar winds. c. sunlight. d. starlight.

a. the interior of Saturn.

One reason that temperatures are higher in the summer than in the winter is that a. the sun is higher in the sky in the summer. b. the sun is closer to our hemisphere in the summer. c. the sun is lower in the sky in the summer. d. the sun is farther from our hemisphere in the summer.

a. the sun is higher in the sky in the summer.

Kepler found that the orbit of Mars is best described as a. a circle with the Sun at the center. b. an ellipse. c. a circle with the Sun o§-center, combined with epicycles. d. a complicated fourth-order polynomial curve.

b. an ellipse

The Moonís orbit around the Earth a. is somewhat elliptical but not enough to a§ect eclipses. b. is elliptical enough to give us an annular solar eclipse when the Moon is near its apogee. c. is elliptical enough to give us an annular lunar eclipse when the Moon is near its apogee. d. is exactly circular.

b. is elliptical enough to give us an annular solar eclipse when the Moon is near its apogee.

The angle between a planetís rotation axis and the perpendicular to the plane of its orbit determines the variability of its seasons. For Jupiter, this axial tilt angle is a. similar to Earth so that seasons are very noticeable. b. only a few degrees so seasons are negligible. c. zero so that seasons do not exist. d. similar to Uranus so that seasons are extreme.

b. only a few degrees so seasons are negligible.

The Summer Solstice is the time when a. the sun crosses the Celestial Equator. b. the noon sun is highest in the sky. c. the noon sun is lowest in the sky.

b. the noon sun is highest in the sky.

Retrograde Motion refers to the a. westward motion of the Moon relative to the horizon. b. westward motion of the planets relative to the stars. c. westward motion of the planets relative to the horizon. d. eastward motion of the Sun relative to the stars. e. eastward motion of the planets relative to the stars.

b. westward motion of the planets relative to the stars.

Mars's orbit is currently a. exactly circular. b. slightly elliptical but not enough to a§ect the intensity of sunlight. c. elliptical enough to make the intensity of sunlight vary by 40 percent. d. elliptical enough to make the intensity of sunlight vary by 6 percent.

c. elliptical enough to make the intensity of sunlight vary by 40 percent.

Mars a. has a solar day that last for two complete orbits around the Sun. b. has a solar day that last for three complete orbits around the Sun. c. has a solar day that is very close to an Earth day in length. d. always keeps the same side toward the Sun so that solar time never changes. e. rotates backwards so that the Sun rises in the West.

c. has a solar day that is very close to an Earth day in length.

The Surveyor series of spacecraft a. orbited Mars in the 1970s. b. surveyed the Moon from lunar orbit in the 1960s. c. made unmanned landings on the Moon in the 1960s. d. made unmanned landings on Mars in the 1970s.

c. made unmanned landings on the Moon in the 1960s.

The Greek theory of Gravity as a force pulling everything toward the center of the universe implied that the Earth should be fixed at the center of the universe. Which of the following models of the Solar System was in accord with that theory? a. the final version of the Ptolemaic System. b. the model of Aristarchus that the Earth goes around the Sun. c. none of these models. d. the Copernican System

c. none of these models.

In comparison to Keplerís Laws of Planetary Motion, Newtonís theory of Universal Gravitation predicted almost the same motions, but with small corrections due to a. velocity-dependent forces that act more strongly on the faster inner planets. b. small time lags caused by the propagation of gravity to each planet. c. the gravitational attractions between di§erent planets. d. the elliptical orbits of the planets. e. the gravitational attraction between each planet and the Sun.

c. the gravitational attractions between di§erent planets.

The Ptolemaic model of the Solar system accounted for the daily rising and setting of the Sun by assuming that a. The Earth moves around the Sun once a day. b. The Earth rotates on its axis once a day. c. The Sun drops below the surface of the Earth when it sets and travels underground to get back to where it rises each day. d. The Sun moves around the Earth once a day.

d. The Sun moves around the Earth once a day.

Which of the following objects is the largest moon of Neptune? a. Ganymede b. Titan c. Callisto d. Triton e. Titania

d. Triton

A sidereal month, is deÖned to be the time it takes for the Moon to a. go from one crossing of the ecliptic to the next. b. go from one crossing of the celestial equator to the next. c. go through a complete cycle of phases. d. complete a full circle on the celestial sphere.

d. complete a full circle on the celestial sphere.

Aristarchus measured the angle between the Sun and the Moon when exactly half of the Moon was illuminated. If he had measured the angle when 3/4 of the Moon was illuminated, he would have found that angle to be a. exactly 90 degrees. b. less than 90 degrees by an amount that was easy for him to measure. c. less than 90 degrees by an amount too small for him to measure. d. greater than 90 degrees.

d. greater than 90 degrees.

For a planet that is following Keplerís Laws, the magnitude of the planetís acceleration is a. a constant. b. proportional to the square of the planetís distance from the Sun. c. proportional to the planetís distance from the Sun. d. inversely proportional to the square of the planetís distance from the Sun. e. inversely proportional to the planetís distance from the Sun.

d. inversely proportional to the square of the planetís distance from the Sun.

Tycho Braheís main contribution to the understanding of planetary motion was to a. propose a new theory. b. explain the observations. c. conform Copernicusítheory. d. make extensive observations. e. disprove Ptolemyís theory.

d. make extensive observations.

Galileo is generally acknowledged to be the first to a. build a telescope. b. design a telescope. c. observe distant objects with a telescope. d. observe the heavens with a telescope.

d. observe the heavens with a telescope.

The ancient Greeks concluded that the Sun is farther from the Earth than the Moon because a. the Sunís angular size is smaller than the angular size of the Moon. b. the Moonís shadow falls on the Earth during a lunar eclipse. c. the Earthís shadow falls on the Moon during a solar eclipse. d. the Moonís shadow falls on the Earth during a solar eclipse. e. the Earthís shadow falls on the Moon during a lunar eclipse.

d. the Moonís shadow falls on the Earth during a solar eclipse.

Tycho Braheís careful observations of the planets agreed, to within observational error, with a. the Tychonic System. b. None of these systems. c. the Copernican System. d. the Ptolemaic System.

d. the Ptolemaic System.

You see a waning quarter Moon high in the night sky. What time is it? a. Midnight. b. 6:00pm c. 10:00am. d. 8:00pm. e. 5:00am

e. 5:00am

Mariner 9 was an early space probe sent to orbit a. Earthís Moon b. Venus c. Jupiter d. Mercury e. Mars

e. Mars