Assignment #2

Question 1

Using the cosmic calendar, where the Big Bang happened January 1, in which month did the Milky Way most likely form?

Answer 1

march

Question 2

What is the ecliptic?

Answer 2

the projection of the Earth’s orbit on the sky

Question 3

Why is the term “arc” used to describe units of measure for angular distance?

Answer 3

to avoid confusion with the minutes and seconds of time

Question 4

What is the very first step of the scientific method?

Answer 4

form a hypothesis

Question 5

What process fo scientists use to determine how nature works?

Answer 5

the scientific method

Question 6

Even though modern astronomers know that stars are scattered through space at different distances, they still use what scientific model to describe celestial locations in the sky?

Answer 6

celestial sphere

Question 7

Where is an observer’s nadir?

Answer 7

the point directly opposite the observer’s zenith

Question 8

What was the purpose of the IAU establishing 88 official constellations?

Answer 8

to define boundaries for constellations including every part of the sky

Question 9

Betelgeuse is the brightest star of which constellation?

Answer 9

Orion

Question 10

What kind of letters are used to identify stars in a constellation?

Answer 10

Greek letters

Question 11

What is the reason for compressing the history of the universe into a single year in the cosmic calendar?

Answer 11

to compare astronomical timescales with human experience

Question 12

At which of the following times would you find the Sun on the celestial equator?

Answer 12

autumnal equinox and vernal equinox

Question 13

At what two celestial locations do the celestial equator and the ecliptic coincide?

Answer 13

vernal equinox and autumnal equinox

Question 14

Why are Northern Hemisphere winters colder than Northern Hemisphere summers?

Answer 14

the light from the sun shines more directly on the Northern Hemisphere during the summer

Question 15

What is the term for a set of beliefs that appears to be based on scientific ideas, but which fails to obey the most basic rules of science?

Answer 15

pseudoscience

Question 16

What letter designation conveys information about a star’s location

Answer 16

the Greek letter

Question 17

What language is the source of most star names, such as Aldebaran and Betelgeuse?

Answer 17

Arabic

Question 18

If the apparent visual magnitude of a star is 7.3, what does this tell us about the brightness of the star?

Answer 18

it is not visible with the unaided eye

Question 19

What is the apparent visual magnitude of a star a measure of?

Answer 19

the star’s brightness as seen by human eyes on Earth

Question 20

If the apparent visual magnitude of star A 3.1, and the apparent visual magnitude of star B is 0.5, how do star A and star B compare in terms of apparent brightness as seen from Earth?

Answer 20

star A is fainter than star B

Question 21

Where is the Zenith for an observer standing at a point on the Earth’s equator?

Answer 21

directly overhead

Question 22

If you were standing at the Earth’s North Pole, which of the following would be located at the zenith?

Answer 22

the north celestial pole

Question 23

What casues the precession of Earth’s rotation axis?

Answer 23

the force of gravity from the Sun and Moon on Earth’s equatorial bulge

Question 24

If our year were twice as long (Earth took twice as many days to complete each orbit), but Earth’s rotation period and axis tilt were unchanged, what would our seasons be like?

Answer 24

the four seasons would each be twice as long as they are now

Question 25

What is the term for the point on the celestial sphere directly above an observer, no matter where on the Earth the observer is located?

Answer 25

zenith

Question 26

The moon has an angular diameter of 0.5 degrees. What is the Moon’s angular diameter in minutes of arc?

Answer 26

30 minutes

Question 27

How much of the night sky lies in north of the celestial equator?

Answer 27

exactly half

Question 28

Through the year, the sun moves eastward among the stars following a line called what?

Answer 28

the ecliptic

Question 29

What is the term for the point in the Earth’s orbit where the Earth is closest to the Sun?

Answer 29

perihelion

Question 30

Within the Northern Hemisphere, what does the vernal equinox mark the star of?

Answer 30

spring

Question 31

What are day and night cycles caused by?

Answer 31

the rotation of Earth

Question 32

If Earth rotated about its axis completely upright, what would we fail to experience?

Answer 32

seasons

Question 33

During which event does the sun reach its most southern point in the celestial sphere within the Northern Hemisphere?

Answer 33

winter solstice

Question 34

When is Earth at its closest point to the sun in its orbit?

Answer 34

when the earth is at perihelion

Question 35

What are the names of constellations that appear never to rise or set?

Answer 35

circumpolar constellations

Question 36

What is an example of asterism?

Answer 36

Big Dipper

Question 37

What is the purpose of the magnitude scale?

Answer 37

it measures the apparent brightness of objects that appear in the sky

Question 38

What best describes a constellation?

Answer 38

a region of the sky containing a certain star pattern

Question 39

Earth’s rapid rotation makes its axis sweep out the shape of a cone. What is this motion known as?

Answer 39

precession