Mid Term

Front 1

When a good observation does not match a prediction made from a theory, a good scientist will

Back 1

either modify or discard the theory.

Front 2

The occurrence of seasons on Earth is due to:

Back 2

Earth's axis being inclined to the ecliptic.

Front 3

For most places on Earth, the sun appears to rise in the east and set in the west on a daily basis because Earth

Back 3

rotates on an axis roughly once every 24 hours.

Front 4

The Moon goes through its phases each month because

Back 4

The amount of the illuminated side of the Moon we see changes over the month

Front 5

The wobble of the Earth on its rotation axis that causes the Earth’s north pole to eventually point at different stars is called

Back 5

precession.

Front 6

During a lunar eclipse, the moon must be in its ________ position.

Back 6

full moon

Front 7

Which of the following is the largest in size?

Back 7

galaxy

Front 8

Without a telescope, the stars of a constellation will appear

Back 8

close together in the sky but may be hundreds of light-years apart from each other in space.

Front 9

What is the definition of an “astronomical unit”?

Back 9

The average distance of Earth to the sun

Front 10

This person first used a telescope to test astronomical theories.

Back 10

Galileo

Front 11

If the distance between Earth and the moon were to double, what would happen to the force of gravity between them?

Back 11

The force of gravity would be 1/4 as strong.

Front 12

The minimum speed necessary to escape from the gravitational pull of an object is called

Back 12

escape speed.

Front 13

According to Kepler, the shapes of the orbits of planets around the sun are:

Back 13

ellipses with the sun at one focus.

Front 14

Which statement about Copernicus’s heliocentric solar system model is true?

Back 14

The planets, including Earth, travel around the sun.

Front 15

What is meant when we say that a planet goes through retrograde motion for several months?

Back 15

The planet appears to reverse direction relative to the stars.

Front 16

Which of the following is a type of electromagnetic wave?

Back 16

a radio wave

Front 17

The distance between two successive crests of a wave is called the wave’s _______ .

Back 17

wavelength

Front 18

Suppose an object is moving towards us. If that object shines a laser on us, the laser’s waves would be _____ when we see them.

Back 18

blueshifted

Front 19

Which of the following has the highest frequency?

Back 19

violet light

Front 20

Which of the following must be the same for all types of electromagnetic radiation in a vacuum?

Back 20

velocity

Front 21

Suppose you are looking at the continuous spectra of two stationary stars. Star Alpha is red. Star Beta is blue. What must be true about these stars?

Back 21

Star Beta must be hotter than Star Alpha.

Front 22

The lowest electron energy level in an atom is

Back 22

the ground state.

Front 23

Which of the following options correctly lists objects in order of increasing size?

Back 23

proton, atom, molecule

Front 24

Which of the following would create an emission spectrum?

Back 24

A thin, hot gas in a tube

Front 25

Which of the following kinds of photons carries the most energy?

Back 25

gamma

Front 26

A particle of light is called a

Back 26

photon

Front 27

Which type of telescope uses only lenses to focus light?

Back 27

refractors

Front 28

What do astronomers call the blurring effect of Earth's turbulent atmosphere?

Back 28

Seeing

Front 29

Which of the following is an advantage of radio telescopes over optical telescopes in astronomy research?

Back 29

Radio telescopes can be used in cloudy weather while optical telescopes can't.

Front 30

What sort of equipment do modern astronomers primarily use to record the light received by telescopes?

Back 30

Charged-coupled devices (CCDs

Front 31

Astronomers have deduced the existence of layers deep inside the sun most directly by studying

Back 31

vibrations on the solar surface.

Front 32

Sunspots are dark because

Back 32

they are cooler than their surroundings.

Front 33

What powers the sun?

Back 33

Hydrogen atoms are fused to create helium and energy.

Front 34

The solar wind is:

Back 34

a stream of hot, fast moving particles escaping off of the sun.

Front 35

The most abundant element in the sun is

Back 35

hydrogen.

Front 36

Most of the sun's energy is produced in the

Back 36

core

Front 37

That part of the sun we can easily see is the

Back 37

photosphere

Front 38

The astronomical term for the total amount of energy produced every second by a star (like our sun) is the

Back 38

luminosity.

Front 39

Suppose Star Alpha exhibits 0.8 arc-seconds of stellar parallax. Suppose Star Beta exhibits 0.1 arc-seconds of stellar parallax. Which of the following statements must be true?

Back 39

Star Alpha is closer than Star Beta.

Front 40

The H-R diagram compares which characteristics about stars?

Back 40

spectral class and luminosity

Front 41

Binary stars are used by astronomers to measure the masses of stars. To do so, astronomers need to know the stars':

Back 41

orbital periods.

Front 42

Suppose Star A has an apparent magnitude of 0.5. Suppose Star B has an apparent magnitude of 2.3. Which of the following statements must be true?

Back 42

Star A appears appears brighter than Star B.

Front 43

Supergiant stars, giant stars, main sequence stars, and subgiant stars are examples of ________ classes.

Back 43

luminosity

Front 44

Astronomers classify stars most directly on the basis of their

Back 44

absorption spectra.

Front 45

Fill in the blank: A low-mass main sequence star will be ____________ than a high-mass main sequence star.

Back 45

less luminous

Front 46

Astronomers measure the proper motion of a stars by

Back 46

observing the star's motion in the sky relative to other stars over periods of decades.

Front 47

21-cm radiation is useful for detecting

Back 47

interstellar bodies of cold hydrogen gas.

Front 48

If a star is behind a dusty nebula, it will appear:

Back 48

fainter and redder than it really is.

Front 49

Emission nebulae glow because:

Back 49

they are heated by hot stars from within.

Front 50

The most common gas in molecular clouds is

Back 50

hydrogen