Astronomy Exam 1

How far from Earth is the moon?

1 light-second

Approximately, what is the age of the Universe?

14 billion years

How long does it take our solar system to complete one orbit around the Milky Way Galaxy?

230 million years

How many arcseconds are in one degree?

3,600

How far from the Earth is the nearest star besides the Sun?

4.2 light-years

Approximately, what is the age of Earth?

4.5 billion years

How many arcminutes are in one degree?

60

How many arcseconds are in one arcminute?

60

If your mass is 60 kg on Earth, what would your mass be on the Moon?

60 kg

How far from Earth is the sun?

8.3 light-minutes

Which or the following statements about scientific models is true? 1) All models that explain nature well are correct 2) A model tries to represent only one aspect of nature 3) A model tries to represent all aspects of nature 4) All current models are correct 5) A model can be used to explain and predict real phenomena

A model can be used to explain and predict real phenomena

On a scale where the Sun is about the size of a grapefruit and the Earth is about 10 meters away, how far away are the nearest stars besides the Sun

About the distance across the United States

Galileo observed which of the following phases of Venus? 1) full 2) crescent 3) new 4) gibbous 5) all of the above

All of the above

If traveling at the speed of light, approximately how far could you travel in one second?

Approximately seven times around the Earth

What causes the apparent retrograde motion of the planets?

As Earth passes another planet, the other planet appears to move backward with respect to the background stars, but the planet's motion does not really change

How did Eratosthenes estimate the size of Earth in 240 B.C.?

By comparing the maximum altitude of the Sun in two cities at different latitudes

The controversial book of this famous person, published in 1543, suggested that Earth and the other planets orbit the Sun:

Copernicus

Suppose we imagine the Sun to be about the size of a grapefruit (about 10 cm across). What describes the size and distance of Earth on the same scale?

Earth is the size of a poppy seed about 10 meters away from the Sun

True or False: A lunar eclipse occurs only when the Moon is new

False

True or False: Columbus was the first person to discover that Earth is round

False

True or False: Earth is always precisely 1 AU from the Sun

False

True or False: Kepler deduced his laws of planetary motion once Newton had published his universal law of gravitation

False

True or False: The Moon and Sun are approximately the same physical size

False

True or False: The Ptolemaic model of the solar system was useless for predicting planetary positions

False

True or False: The solar system contains about 250 billion stars

False

True or False: There is no gravity in space

False

True or False: When energy is converted from one form to another, a tiny amount is inevitably lost

False

When we see Venus in its full phase, what phase would the Earth be in as seen by a hypothetical Venetian?

Full

Who discovered that Jupiter has moons?

Galileo

One of the "nails in the coffin" for the Earth-centered universe was:

Galileo's observations of the moons of Jupiter

How does the Space Shuttle take off?

Hot gas shoots out from the rocket and, by conservation of momentum, the shuttle moves in the opposite direction

The principle of Occam's Razor states that:

In explaining natural phenomena, the simplest explanation consistent with the observations is to be preferred

On a cosmic calendar, in which the history of the universe is compressed into 1 year, when did the dinosaurs become extinct?

In late December

What makes the North Star, Polaris, special?

It appears very near the north celestial pole

Where does the energy come from that your body uses to keep you alive?

It comes from the foods you eat

Which of the following statements does not use the term light-year in an appropriate way? 1) It will take the Voyager spacecraft about 20,000 years to travel just 1 light-year 2) It will take me light-years to complete this homework assignment. 3) It's about 4 light-years from here to Alpha Centauri 4) A light-year is about 10 trillion kilometers 5) The Milky Way Galaxy is about 100,000 light-years in diameter

It will take me light-years to complete this homework assignment

Who discovered that the orbits of planets are ellipses?

Kepler

The mass of Jupiter can be calculated by:

Measuring the orbital period and distance of one of Jupiter's moons

The fact that Voyager 10 continues to speed out of the solar system, even though its rockers have no fuel, is an example of:

Newton's first law of motion

Has Polaris always been the "North Star"?

No, because the Earth's axis slowly changes the direction it points.

You are standing on Earth's equator. Which way is Polaris, the North star?

On the northern horizon

Which of the following statements about the Milky Way Galaxy is not true? 1) Our solar system is located very close to the center of the Milky Way Galaxy 2) Our rotation of the galaxy takes about 200 million years 3) The galaxy about the 100,000 light-years in diameter 4) It contains between 100 billion and 1 trillion stars

Our solar system is located very close to the center of the Milky Way Galaxy

Who developed a system for predicting planetary positions that remained in use for some 1,500 years?

Ptolemy

How many galaxies are there in the observable universe?

Roughly the same as the number of stars in our galaxy

If traveling at the speed of light, approximately how far could you travel in one second?

Seven times around the earth

Which of the following is largest? 1) Size of Pluto's orbit 2) Size of a typical galaxy 3) 1 light-year 4) Distance to the nearest star

Size of a typical galaxy

Which of the following is the smallest? 1) 1 AU 2) 1 light-second 3) Size of a typical star 4) Size of a typical planet

Size of a typical planet

In addition to the conditions required for any solar eclipse, what must also be true in order for you to observe a total solar eclipse?

The Moons umbra must touch the area where you are located

Why is it summer in the Northern Hemisphere when it is winter in the Southern Hemisphere?

The Northern Hemisphere is tilted toward the Sun and receives more direct sunlight

An astronomical unit is:

The average distance between Earth and the Sun

Which of the following is the reason for the solar day being longer than a sidereal day? 1) The combined effect of the rotation of Earth and its orbit about the Sun 2) The non-circular orbit of Earth around the Sun 3) Precession of Earth's axis 4) Earth year being a non-integer number of Earth days 5) The tilt of Earth's axis

The combined effect of the rotation of Earth and its orbit about the Sun

The Earth is instantly replaced in its orbit by a speck of dust. Which statement best describes the subsequent orbital motion of that piece of dust?

The dust particle will continue in the same orbit as the Earth did, orbiting the Sun in 1 year

You are standing on a scale in an elevator. Suddenly you notice your weight decreases. What do you conclude?

The elevator is accelerating downwards

What conditions are required for a lunar eclipse?

The phase of the Moon must be full, and the nodes of the Moon's orbit must be nearly aligned with Earth and the Sun

What conditions are required for a solar eclipse?

The phase of the Moon must be new, and the nodes of the Moon's orbit must be nearly aligned with Earth and the Sun

What is the ecliptic plane?

The plane of Earth's orbit around the sun

What happens during the apparent retrograde motion of a planet?

The planet appears to move eastward with respect to the stars over a period of many sights

The total number of stars in the observable universe is about:

The same as the number of grains of sand on all the beaches on Earth

Why did Ptolemy have the planets orbiting Earth on "circles upon circles" in his model of the universe?

To explain the fact that planets sometimes appear to move westward, rather than eastward, relative to the stars in our sky

True or False: A solar eclipse occurs only when the Moon is new

True

True or False: One light year is about 10 trillion kilometers

True

True or False: The moon and the Sun are approximately the same angular size

True

True or False: The moon is constantly falling toward Earth

True

True or False: The solar system is a member of a galaxy containing approximately 250 billion stars.

True

Which of the following critical features of the heliocentric model leads to Venus exhibiting a full range of phases? 1) Venus physically distorts from a sphere as it orbits the sun 2) When Venus is closer to the Sun, it moves faster 3) Venus passes on the far-side of the sun from the Earth's perspective

Venus passes on the far-side of the sun from the Earth's perspective

Kepler's second law, which states that as a planet moves around its orbit it sweeps out equal areas in equal times, means that:

a planet travels faster when it is nearer to the Sun and slower when it is farther from the Sun

Gasoline is useful in cars because it has:

chemical potential energy

In which direction does a quarter moon rise?

east

If the Moon was setting at 6 A.M., the face of the Moon must be:

full

Which of the following is not a phase of the Moon?

half moon

The ultimate source of energy is that powers the Sun is:

mass energy of hydrogen fusing into helium

At approximately what time would be a full moon be on your meridian?

midnight

In the Ptolemaic model of the solar system, Venus should exhibit which of the following phases: 1) new 2) crescent 3) full 4) new & crescent 5) crescent & full

new & crescent

If you see Polaris directly overhead at midnight, you must be at:

the North Pole

Orion is visible on winter evenings but not summer evenings because of:

the location of earth in its orbit

0 degrees Kelvin is:

the temperature at which all random particle motion stops

The tides on Earth are an example of:

the universal law of gravitation

If the Moon is rising at midnight, the phase of the Moon must be:

third quarter