Exam 1

Question 1

A star is 230 light-years away. The light we see tonight from that star left it

Answer 1

230 years ago

Question 2

The point in the sky directly above your head at any given time is called the

Answer 2

Zenith

Question 3

T OR F: The path that the Sun appears to make in the sky over the course of a year is called the celestial equator.

Answer 3

FALSE

Question 4

The great astronomer of ancient times who summarized and improved a system of circles upon circles to explain the complicated motions of the planets (and published the system in a book now called The Almagest) is:

Answer 4

Ptolemy

Question 5

The scientist who first devised experimental tests to demonstrate the validity of the heliocentric model of the solar system was

Answer 5

Galileo

Question 6

The celestial sphere turns once around each day because

Answer 6

the planet on which we live is rotating

Question 7

Which ancient Greek thinker suggested (long before Copernicus) that the Earth is moving around the Sun?

Answer 7

Aristarchus

Question 8

T OR F: At the Earth’s equator, you would see the celestial poles on your horizon.

Answer 8

TRUE

Question 9

How did Eratosthenes measure the size of the Earth?

Answer 9

by measuring the height of the Sun in the sky on the same day in two cities at different latitudes 

Question 10

In an ellipse, the ratio of the distance between the foci and the length of the major axis is called:

Answer 10

The eccentricity

Question 11

Every object will continue to be in a state of rest or move at a constant speed in a straight line unless it is compelled to change by an outside force.

Answer 11

Newtons First Law

Question 12

The change of motion of a body is proportional to an in the direction of the force acting on it.

Answer 12

Newtons Second Law

Question 13

For every action there is an equal and opposite reaction (or: the mutual actions of two bodies upon each other are always equal and act in opposite directions)

Answer 13

Newtons Third Law

Question 14

How do you calculate the semimajor axis given the major axis?

Answer 14

major / 2

Question 15

The closer the eccentricity is to 1 the ellipse is more
_______

Answer 15

elongated

Question 16

The closer the eccentricity is to 0, the ellipse is more ________

Answer 16

circular

Question 17

T OR F: Kepler’s third law relates a planet’s orbital period to the semi-major axis of the orbit

Answer 17

TRUE

Question 18

Is the following statement about electromagnetic radiation True? the radiation consists of tiny charged particles given off by the nuclei of atoms 

Answer 18

YES

Question 19

Which of the following has the longest wavelength? Gamma, Light, Microwave, Radio

Answer 19

RADIO

Question 20

T OR F:
For all electromagnetic waves, the frequency multiplied by the wavelength will be the same constant number.

Answer 20

TRUE

Question 21

Frequency of radiation is proportional to temperature

Answer 21

Wiens Law

Question 22

total energy radiated increases rapidly with temperature

Answer 22

Stegans Law

Question 23

The energy flux from a blackbody at temperature T is proportional to the fourth power of its absolute temperature.

Answer 23

Stefan Boltzmann Law

Question 24

source motion changes the perceived wavelength of emitted light

Answer 24

The Doppler Effect

Question 25

Can observe 24 hours a day Clouds, rain, and snow don’t interfere Observations at an entirely different frequency; get totally different information

Answer 25

Advantages of Radio Astronomy

Question 26

Mercury, Venus, Earth, and Mars

Answer 26

Terrestrial Planets

Question 27

Jupiter, Saturn, Uranus, and Neptune

Answer 27

Jovian Planets

Question 28

Planetary orbits are ellipses, with the Sun at one focus.

Answer 28

Keplers First Law

Question 29

Perihelion

Answer 29

the closest approach

Question 30

Aphelion

Answer 30

the greatest approach

Question 31

The imaginary line connecting Sun and planet sweeps out

Answer 31

Keplers Second Law

Question 32

Earth is closer to the Sun in January. From this fact, Kepler’s 2nd law tells us: a) Earth orbits slower in January. b) Earth orbits faster in January. c) Earth’s orbital speed doesn’t change.

Answer 32

B. Earth orbits faster in January

Question 33

Square of period of planet’s orbital motion is proportional to cube of semi-major axis.

Answer 33

Keplers Third Law

Question 34

the time it takes a planet to travel once around the Sun

Answer 34

Period

Question 35

the average distance from Earth to the Sun

Answer 35

AU

Question 36

any circle on the surface of a sphere whose center is at the center of the sphere.

Answer 36

Great circle

Question 37

Great circles that pass through both the North and South Poles are called

Answer 37

Meridians