Astronomy Final Review

Define aphelion

The point at which an object orbiting the Sun is farthest from the Sun

When you see the Sun, you are seeing it as it was approximately

8 minutes ago

When you see a star that is 50 light-years away, you are seeing the star     

as it looked in the year 1973

What makes the North Star, Polaris, special?

It appears very near the north celestial pole

When traveling north from the United States into Canada, you'll see the North Star (Polaris) getting

higher in the sky.

Three days after full moon, the moon's phase is

waning gibbous

Which of the following best explains the success of the central African rainfall-prediction technique of observing the waxing crescent Moon?

The Moon's orientation varies seasonally, and so does the weather.

Galileo observed all of the following. Which observation offered direct proof of a planet orbiting the Sun?

phases of Venus

Galileo challenged the idea that objects in the heavens were perfect by

observing sunspots on the Sun and mountains on the Moon

Which choice lists the following objects in order of their distance to Earth (from closest to farthest)?

Sun, Polaris, Andromeda Galaxy

Roughly how many stars are in the Milky Way Galaxy?

100 billion

If there is a full moon on April 15, when will the next full moon be?

May 14

Which of the following correctly describes the meridian in your sky?

a half-circle extending from your horizon due north, through your zenith, to your horizon due south

What is a circumpolar star?

a star that always remains above your horizon and appears to rotate around the celestial pole

The names of the seven days of the week are based on the

seven naked-eye objects that appear to move among the constellations.

What practical value did astronomy offer to ancient civilizations?

It helped them keep track of time and seasons, and it was used by some cultures for navigation.

He discovered that Jupiter has moons.

Galileo

A  light-year is  

the distance light travels in one year

Which of the following statements does not use the term angular size or angular distance correctly?

The angular distance between those two bright stars in the sky is about 2 meters

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

He discovered that the orbits of planets are ellipses.

Kepler

Suppose a comet orbits the Sun on a highly eccentric orbit with an average (semimajor axis) distance of 1 AU. How long does it take to complete each orbit, and how do we know?

One year, which we know from Kepler's third law.

How long does it take Earth to rotate once on its axis?    

1 day

Lunar eclipses can occur only during a

full moon

A week after full moon, the moon’s phase is

first quarter

When did Copernicus live?

about 500 years ago

Earth is farthest from the Sun in July and closest to the Sun in January. During which Northern Hemisphere season is Earth moving fastest in its orbit?

winter

Which of the following has your "address" in the correct order?

Earth, solar system, Milky Way, Local Group, Local Supercluster

We cannot see a new moon in our sky because

a new moon is quite near the Sun in the sky

How did the Ptolemaic model explain the apparent retrograde motion of the planets?

It held that the planets moved along small circles that moved on larger circles, also known as epicycles, around Earth

Because angular momentum is conserved, a planet at its farthest point from the Sun travels

slowest

Suppose an object is moving in a straight line at 50 miles/hr. According to Newton's first law of motion, the object will

continue to move in the same way until it is acted upon by a force

Newton's second law of motion tells us that the net force applied to an object equals its

mass times acceleration

In the formula E = mc², what does m represent?

mass

Absolute zero is

0 Kelvin

Why is Newton's version of Kepler's third law so useful to astronomers?

it can be used to determine the masses of many distant objects

The force of gravity between two objects depends on their

masses and distance

From lowest frequency to highest frequency, which of the following correctly orders the different categories of electromagnetic radiation?

radio, infrared, visible, ultraviolet, x-ray, gamma

Which of the following has the longest wavelength ?

infrared

Which of the following has the longest wavelength ?

orange light

Gamma rays have a very small

wavelength

You can see a flower because it

reflects visible light

A particle of light is called a(n)   

photon

How much electrical charge does an atom with 6 protons, 6 neutrons, and 4 electrons have?

a positive chare of +2

H₂ is the chemical symbol for

molecular hydrogen

Carbon-13 has six protons; how many neutrons does it have? 

7

Suppose you drop a 10-pound weight and a 5-pound weight on the Moon, both from the same height at the same time. What will happen?

both will hit the ground at the same time

What quantities does angular momentum depend upon?

mass, velocity, and radius

If your mass is 30 kg on Earth, what would your mass be on the Moon?

30 kg

In the formula E=mc², what does c represent?  

the speed of light in a vacuum

Which of the following has the lowest frequency?

infrared

From shortest to longest wavelength, which of the following correctly orders the different categories of electromagnetic radiation?

gamma rays, x-rays, ultraviolet, visible light, infrared, radio

Which of the following has the highest frequency?

gamma rays

Suppose you want to know the chemical composition of a distant star. Which piece of information is most useful to you?

the wavelengths of spectral lines in the star’s spectrum

The spectra of most galaxies show redshifts. This means that their spectral lines

have wavelengths that are longer than normal

One isotope of neon has 10 protons and 12 neutrons.  What is its atomic mass number?

22

NH₃ is the chemical symbol for

ammonia

Consider an atom of oxygen in which the nucleus contains 8 protons and 7 neutrons. What is its atomic number and atomic mass number?

atomic number = 8; atomic mass number = 15

Which of the following represents a case in which you are not accelerating?

driving in a straight line at 60 miles per hour

Why do astronauts feel weightless in the Space Station?

because the Space station is constantly in free-fall around Earth

Which of the following statements correctly describes the law of conservation of energy?

the total quantity of energy in the universe never changes

The allowed shapes for orbits under the force of gravity are

ellipses, parabolas, and hyperbolas

Which of the following has the highest frequency?

ultraviolet

The wavelength of a wave is

the distance between two adjacent peaks of the wave

The spectra of most galaxies show redshifts. This means that their spectral lines

have wavelengths that are longer than normal

Grass appears green because

it reflects green light and absorbs other colors

An atom in an excited state contains more of what type of energy than the same atom in the ground state?

electric potential energy

Once a spacecraft has left Earth's orbit, it will continue to travel out of the solar system, even though its rockets have no fuel. This is an example of

Newton's first law of motion

Considering Einstein's famous equation, E = mc², which of the following statements is true?

a small amount of mass can be turned into a large amount of energy

Who discovered the basic law that describes how gravity works?

Newton

Which of the following has the shortest wavelength?

X-rays

Which of the following has the shortest wavelength?

green light

Suppose you see two stars: a blue star and a red star. Which of the following can you conclude about the two stars? Assume that no Doppler shifts are involved.

the blue star has a hotter surface temperature than the red star

You observe a distant galaxy. You find that a spectral line normally found in the visible part of the spectrum is shifted toward the infrared. What do you conclude?

the galaxy is moving away from you

NH₃ is the chemical symbol for

ammonia

An atom of the element tin has an atomic number of 50 and an atomic mass number of 120. If it is neutral, how many protons, neutrons, and electrons does it have?

50 protons, 70 neutrons, 50 electrons

Astronomers have decided that, rather than being a planet, Pluto is really just a large member of

the Kuiper belt

The terrestrial planets in our solar system are

Mercury, Venus, Earth, and Mars

What is the Oort cloud?

it is the spherical distribution of the trillion or so comets thought to orbit the Sun at great distances

This is the second planet from the Sun.

Venus

These planets have no known moons

Venus and Mercury

This is the fifth planet from the Sun

Jupiter

Approximately how far is Uranus from the Sun?

20 a.u.

Approximately how far is Jupiter from the Sun?

5 a.u.

In essence, the nebular theory holds that

our solar system formed from the collapse of an interstellar cloud of gas and dust

Astronomers estimate the age of our solar system to be approximately

4.6 billion years

Suppose you start with 1 kilogram of a radioactive substance that has a half-life of 8 years. Which of the following statements will be true after 8 years pass?

you’ll have 0.5 kilogram of the radioactive substance remaining

The combined mass of all the asteroids in the asteroid belt is

less than that of any terrestrial planet

What is a meteorite?

a fragment of an asteroid from our solar system that has fallen to Earth’s surface

What is the solar wind?

a stream of charged particles flowing outward from the surface of the Sun

Suppose you put two protons near each other. Because of the electromagnetic force, the two protons will

repel each other

The proton-proton chain is

the specific set of nuclear reactions through which the Sun fuses hydrogen into helium

Where are most of the known asteroids found?

between the orbits of Mars and Jupiter

What is the Kuiper belt?

a region of the solar system beginning just beyond the orbit of Neptune that contains many icy bodies, including Pluto

Which planet has the highest average surface temperature, and why?

Venus, because of its dense carbon dioxide atmosphere

This is the smallest planet. Since it has virtually no atmosphere, its surface is extremely hot in the daytime and extremely cold in the nighttime. 

Mercury

This planet rotates backwards on its axis

Venus

This is the largest terrestrial planet

Earth

Approximately how far is Saturn from the Sun?

10 a.u.

Approximately how far is Neptune from the Sun?

30 a.u.