Chapter 1

Question 1

What are three ways you can observe the night sky?

Answer 1

Binoculars, Telescopes, and Eyes

Question 2

Is there a difference in the sky depending on whether you live in the Southern or Northern Hemisphere?

Answer 2

Yes, star charts vary

Question 3

Is there a difference in the sky depending on the season?

Answer 3

Yes

Question 3

Is there a difference in the sky depending on the season?

Answer 3

Yes

Question 4

What are the two largest celestial objects we can view?

Answer 4

Sun and Moon

Question 5

Why is there a trend of east-to-west motion when observing the sun, the moon, and the stars?

Answer 5

This is because of the earth’s rotation on its axis; because the earth is spinning in the opposite direction.

Question 6

What is this trend of the earth’s rotation called?

Answer 6

Diurnal Motion

Question 7

What is the approximate rotation time of the earth that relates to other objects in the sky as well?

Answer 7

Approximate 24-hour cycle

Question 8

Name the concept that is useful for understanding the positions and motions of stars

Answer 8

Celestial sphere

Question 9

Name the concept that involves expanding the earth’s equator into space

Answer 9

Celestial equator

Question 10

What are the constellations called that are close enough to the celestial pole that they are visible all night, all year round?

Answer 10

Circumpolar constellations

Question 11

Since the 23 hours and 56 minutes period is the length of time it takes the earth to turn as seen from a distant star, this is called?

Answer 11

Sidereal day

Question 12

Describe the difference between the sidereal day and the solar day

Answer 12

The sidereal day is the true rotation rate of the earth as seen from a distant star. The solar day is how long it takes for the sun to return to its highest point in the sky as viewed from the location on earth

Question 13

Since stars rise two hours earlier every month, they rise how many hours earlier after six months?

Answer 13

12 hours

Question 13

Since stars rise two hours earlier every month, they rise how many hours earlier after six months?

Answer 13

12 hours

Question 14

Why is it difficult to observe planets, globular clusters, and nebulae when the moon is full?

Answer 14

It washes out nearly everything else in the sky

Question 15

The moon rises (on average) about _________ later each day?

Answer 15

50 minutes

Question 16

Why is it ironic that the moon is called “the moon” in regard to the gravitational pull of the earth and sun?

Answer 16

The gravitational pull of the sun on the moon is about twice the pull of the earth on the moon

Question 17

The phases of the moon are not related to the earth’s shadow, but to the ________ of the day side of the moon we can see from our position.

Answer 17

Percentage

Question 18

It takes ______ days for the moon to go through its phases, and _____ days for its orbital period.

Answer 18

29.3, 27.5

Question 19

The motion of the planets is complicated because their apparent motion in the sky is the combination of their _______ around the sun, plus the _____________ in position due to Earth’s motion around the sun.

Answer 19

True motion, apparent shift

Question 20

What is responsible for the seasons on the earth?

Answer 20

The earth’s rotation axis that is tilted relative to its orbit around the sun by 23.4 degrees

Question 21

Describe what the two coordinate systems widely used in astronomy are based on.

Answer 21

The first is based on our local horizon. The second is based on the celestial sphere.

Question 22

________ describes how high above the horizon an object is (in angle).

Answer 22

Altitude

Question 23

_________ describes how far along the horizon an object is to the right of due north.

Answer 23

Azimuth

Question 24

Equatorial coordinates are based on the ______________. In particular, they are based on the celestial _________.

Answer 24

Celesital sphere, equator

Question 25

Stars with a declination that is less than your latitude will pass ________ of zenith when they cross the meridian, and stars with a greater declination will pass ________ of zenith.

Answer 25

South, North

Question 26

Which RA coordinates can be seen depends on the time of _____ and the time of _____.

Answer 26

Day, Year

Question 27

Once calibrated on an object whose RA and Dec you know, you can use ________ circles on a telescope to find any other RA or Dec.

Answer 27

Setting

Question 28

What is the best way to get a feel for the motions in the sky?

Answer 28

It’s best to get outside and watch.

Question 29

A star wheel or planisphere helps you find stars by lining up the ______ with the ______ on the planisphere.

Answer 29

Date, Time

Question 30

A planisphere helps find constellations, but will not help with ____ or ____.

Answer 30

Planets, Moon