Chapter 1

The farthest bright galaxies that modern telescopes are capable of seeing are up to A) 1 million light years away. B) 10 million light years away. C) 1 trillion light years away. D) 1 billion light years away. E) 10 billion light years away.

Suppose we imagine the Sun to be about the size of a grapefruit. How big an area would the orbits of the eight planets of the Solar System cover? A) the size of a small city B) the size of a western state (e.g., Colorado) C) the size of a typical dorm room D) the size of a typical campus building E) the size of a typical campus

Earth is made mostly of metals and rocks. Where did this material come from? A) It was made by nuclear fission of uranium and other radioactive materials. B) It was created by chemical reactions in interstellar space. C) It was produced in the Big Bang. D) It was produced by nuclear fusion in stars. E) It was made by our Sun.

What is nuclear fusion? A) the process of splitting nuclei to produce energy B) the process of turning matter into pure energy C) an explosion caused by putting together two volatile chemicals D) a process that only occurs in bombs E) the process of combining lightweight nuclei to make heavier nuclei

Which of the following statements does not use the term light-year in an appropriate way? A) A light-year is about 10 trillion kilometers. B) It's about 4 light-years from here to Alpha Centauri. C) It will take the Voyager spacecraft about 20,000 years to travel just 1 light-year. D) The Milky Way Galaxy is about 100,000 light-years in diameter. E) It will take me light-years to complete this homework assignment.

Light takes approximately one second to travel from the Earth to the Moon. This means that the Moon is approximately A) twice the distance from the Earth to the Sun. B) 1 light year from the Earth. C) 1 astronomical unit from the Earth. D) 3,000 kilometers from the Earth. E) 300,000 kilometers from the Earth.

One light-hour is the distance that light travels in an hour. How far is this, in kilometers? (Recall 7) that the speed of light is 300,000 km/s.) A) 1.08 billion km B) 9.46 trillion km C) 100 million km D) 300,000 km E) 18 million km

Suppose we look at a photograph of many galaxies. Assuming that all galaxies formed at the same time after the Big Bang, which galaxy appears to us as the youngest? A) the galaxy that is closest to us B) the galaxy that appears bluest to us C) the galaxy that appears largest to us D) the galaxy that is furthest from us E) All galaxies would appear to have the same age.

Suppose we imagine the Sun to be about the size of a grapefruit (about 10 cm across). Which of the following describes the size and distance of Earth on the same scale? A) Earth is the size of a point about 1 meter away from the Sun. B) Earth is the size of a point about 15 meters away from the Sun. C) Earth is the size of a marble about 25 miles away from the Sun. D) Earth is the size of a golf ball about 1 meter away from the Sun. E) Earth is the size of a golf ball about 15 meters away from the Sun.

Which of the following correctly describes the concept of galactic recycling? A) In the formation of a star, no matter is wasted as all excess material ends up recycled into planets. B) New stars are continuously being formed in the Milky Way out of gas that has been ejected from a previous generation of stars. C) Stars near the center of the Milky Way are continually recycled to the outskirts of the disk by their orbital motion. D) New galaxies are continuously being formed out of gas ejected from a previous generation of galaxies. E) Life is continuously being spread from star to star in the Milky Way.

What is the Sun mainly made of? A) nearly equal portions of all the elements B) oxygen and carbon C) hydrogen and helium D) carbon and nitrogen E) hydrogen and oxygen

Which of the following is smallest? A) 1 AU B) Size of a typical star C) 1 Light-Second D) Size of a typical planet

Which of the following is largest? A) distance to the nearest star (other than our Sun) B) size of Pluto's orbit C) size of a typical galaxy D) 1 light-year

On the 1-to-10-billion scale, about how far is it to the nearest stars besides the Sun? A) 10,000 kilometers B) 400 kilometers C) 1,000 kilometers D) 4,400 kilometers E) 4 kilometers

Suppose we imagine the Sun to be about the size of a grapefruit (about 10 cm across). How far away are the nearest stars (the three stars of Alpha Centauri)? A) the length of a football field B) 2.5 miles C) 2,500 miles D) 25,000 miles E) 250 miles

If we use 1 millimeter to represent 1 light-year, how large in diameter is the Milky Way Galaxy? A) 100 millimeters B) 100 meters C) 100 kilometers D) 1 kilometer E) 1 million millimeters

Which of the following best describes the Milky Way Galaxy? A) a spiral galaxy with a disk about 100,000 light-years in diameter and containing about 100,000 stars B) a spiral galaxy with a disk about 100,000 light-years in diameter and containing between 100 billion and 1 trillion stars C) a spiral galaxy with a disk about a billion kilometers in diameter and containing between 100 million and 1 billion stars D) a spherically shaped collection of stars including our solar system and about a dozen other solar systems, stretching about 4 light-years in diameter E) a spherically shaped collection of about 1 million stars that is about 100 light-years in diameter

How many galaxies are there in the observable universe? A) about as many as the number of grains of sand on all the beaches on Earth B) roughly (within a factor of the same as the number of stars in our galaxy C) infinity D) roughly a thousand times more than the number of stars in our galaxy E) about as many as the number of stars we see in the sky with our naked eyes

On the scale of the cosmic calendar, in which the history of the universe is compressed to 1 year, how long has human civilization (i.e., since ancient Egypt) existed? A) a few hours B) less than a millionth of a second C) about a month D) a few seconds E) about half the year

On a cosmic calendar, in which the history of the universe is compressed into 1 year, when did the dinosaurs become extinct? A) in late October B) in late August C) in late November D) in late September E) in late December

On a cosmic calendar, in which the history of the universe is compressed into 1 year, when did Kepler and Galileo first discover that we live on a planet in a solar system? A) 1 week ago B) December 30 C) 1 day ago D) 1 second ago E) December 25

Approximately how fast is a person located at the Earth's equator traveling due to the rotation of the Earth? A) 170 km/hr B) 17 km/hr C) 17,000 km/hr D) 1,700 km/hr E) not moving at all

How long does it take our solar system to complete one orbit around the Milky Way Galaxy? A) 1 million years B) 230 million years C) 100 million years D) 230 thousand years E) 10 thousand years

Which of the following statements about the Milky Way Galaxy is not true? A) The galaxy is about 100,000 light-years in diameter. B) One rotation of the galaxy takes about 200 million years. C) Our solar system is located very close to the center of the Milky Way Galaxy. D) It contains between 100 billion and 1 trillion stars.

Which of the following correctly lists speeds from slowest to fastest? A) Earth's speed of rotation on its axis, typical speeds of stars in the local solar neighborhood relative to us, Earth's speed of revolution about the Sun, the speed of our solar system orbiting the center of the Milky Way Galaxy, the speeds of very distant galaxies relative to us B) the speed of our solar system orbiting the center of the Milky Way Galaxy, Earth's speed of revolution about the Sun, Earth's speed of rotation on its axis, the speeds of very distant galaxies relative to us, typical speeds of stars in the local solar neighborhood relative to us C) Earth's speed of revolution about the Sun, typical speeds of stars in the local solar neighborhood relative to us, Earth's speed of rotation on its axis, the speed of our solar system orbiting the center of the Milky Way Galaxy, the speeds of very distant galaxies relative to us D) the speeds of very distant galaxies relative to us, typical speeds of stars in the local solar neighborhood relative to us, Earth's speed of rotation on its axis, Earth's speed of revolution about the Sun, the speed of our solar system orbiting the center of the Milky Way Galaxy E) Earth's speed of revolution about the Sun, Earth's speed of rotation on its axis, the speed of our solar system orbiting the center of the Milky Way Galaxy, typical speeds of stars in the local solar neighborhood relative to us, the speeds of very distant galaxies relative to us

Most of the mass in the Milky Way Galaxy is located A) in the halo (above/below the disk). B) in the central bulge of the galaxy. C) in the stars in the spiral arms. D) in the gas and dust. E) within the disk.

The distribution of the mass of the Milky Way Galaxy is determined by A) studying how stars are distributed in the Milky Way. B) studying the rotation of the galaxy. C) counting the number of stars. D) determining the amount of gas and dust. E) weighing various parts of the Milky Way.

From the fact that virtually every galaxy is moving away from us and more distant galaxies are moving away from us at a faster rate than closer ones, we conclude that A) the universe is shrinking. B) the Milky Way Galaxy is expanding. C) we are located at the center of the universe. D) the farthest galaxies will eventually be moving faster than the speed of light. E) the universe is expanding.

By studying distant galaxies in the 1920s, Hubble made the following important discovery that led us to conclude that the universe is expanding. A) All galaxies outside the Local Group are moving away from us, and the farther away they are, the faster they're going. B) All galaxies contain billions of stars, and all galaxies have spiral shapes. C) All galaxies outside the Local Group are orbiting the Local Group. D) All galaxies outside the Local Group are moving away from us, and all are moving away at nearly the same speed. E) All galaxies were born at the same time, and all will die at the same time.

Imagine that we put a raisin cake into the oven, with each raisin separated from the others by 1 cm. An hour later, we take it out and the distances between raisins are 3 cm. If you lived in one of the raisins and watched the other raisins as the cake expanded, which of the following would you conclude? A) More distant raisins would be moving away from you faster. B) All raisins would be moving away from you at the same speed. C) More distant raisins would be moving away from you more slowly. D) It depends: If you lived in a raisin near the left side of the cake, you'd see other raisins moving away from you, but they'd be coming toward you if you lived in a raisin near the right side of the cake.

How many seconds are in one year? (Calculate this, do not look it up.) A) about 3,600 (3.6 × 103) B) about 86 thousand (86,000, or 8.6 × 105) C) about 30 million (30,000,000, or 3 × 107) D) about 380 million (380,000,000, or 3.8 × 108)

The speed of light is about 300,000 km/s (3 × 105 km/s). How far does light travel in 30 seconds? A) 900 thousand km (900,000, or 9 × 105 km) B) 9 million km (9,000,000, or 9 × 106 km) C) 10 thousand km (10,000, or 106 km) D) 300 thousand km (300,000, or 3 × 105 km)

One light-minute is the distance light travels in one minute. The speed of light is about 300,000 33) km/s (3×105 km/s). How far is one light-minute? A) 300 thousand km (300,000, or 3 × 105 km) B) 1.08 billion km (1,080,000,000, or 1.08 × 109 km) C) 18 million km (18,000,000, or 1.8 × 107 km) D) 9.46 trillion km (9,460,000,000,000, or 9.46 × 1012 km)

One light-minute is the distance light travels in one minute. The speed of light is about 300,000 km/s (3 × 105 km/s). How far is 5 light- minutes? A) 1.5 million km (1,500,000, or 1.5 × 10^6 km) B) 47.3 trillion km (47,300,000,000,000, or 4.73 × 10^13 km) C) 5.4 billion km (5,400,000,000, or 5.4 × 10^9 km) D) 90 million km (90,000,000, or 9 × 10^7 k)

One light-hour is the distance light travels in one hour. The speed of light is about 300,000 km/s 35) (3 × 105 km/s). How far is 1 light-hour? A) 9.46 trillion km (9,460,000,000,000, or 9.46 × 1012 km) B) 300 thousand km (300,000, or 3 × 105 km) C) 18 million km (18,000,000, or 1.8 × 107 km) D) 1.08 billion km (1,080,000,000, or 1.08 ×109 km)

The planet Neptune is, on average, about 4.5 billion km from the sun. How long does it take light from the sun to reach Neptune? (Recall that the speed of light is about 300,000 km/s) A) about 4 seconds B) about 4 minutes C) about 4 days D) about 4 hours

One light-year is the distance light travels in one year. The speed of light is about 300,000 km/s 37) (3 × 105 km/s). How far is 1 light-year? A) 300 thousand km (300,000, or 3 × 105 km) B) 1.08 billion km (1,080,000,000, or 1.08 × 109 km) C) 18 million km (18,000,000, or 1.8 × 107 km) D) 9.46 trillion km (9,460,000,000,000, or 9.46 × 1012 km)

What is the diameter of the galaxy, in km? A) About 100,000 (10^5) B) About 1 million trillion km (10^18 km) C) About 10 trillion km (10^13) D) About 1 Billion Trillion km (10^21km)

If the entire galaxy (with a diameter of 100,000 light years) were represented by a circle with a 39) diameter of 4,400 km (similar to the width of the continental United States), then how far apart would be the Sun and its nearest stellar neighbor, Proxima Centauri (which is 4.2 light years away)? A) about 200 meters (about 2 football fields) B) about 0.2 meters (about the length of an adult's forearm) C) about 2 meters (about 2 long footsteps) D) about 20 meters (about the size of a large classroom)

The Earth has a radius of about 6,000 km. How long would it take for an object traveling at the speed of light to circle the earth? (Recall that the speed of light is 300,000 km/s) A) 1/ 6000 of a second (0.00015 s) B) 1/2 of a second (0.5 s) C) 1/50 of a second (0.02s) D) 1/300,000 of a second (0.0000033 s)

Our solar system is located about 27,000 light-years from the galactic center. How far does our solar system travel in one orbit? A) 54,000 light-years B) 100,000 light-years C) 85,000 light-years D) 170,000 light-years

Our solar system is located about 27,000 light-years from the galactic center. How far does our solar system travel in one orbit? A) 8.5 × 1017 km B) 1.7 × 1018 km C) 1018 km D) 5.4 × 1017 km

Stars nearby to our sun have an average relative speed of about 70,000 km/hour. How fast is that in km/s? A) about 1200 km/s B) about 4.2 million km/s C) about 3000 km/s D) about 20 km/s