Chapter 2 Flashcards
Which of the following best describes the modern definition of a constellation
A region of the celestial sphere
The number of official constellations (as defined by the International Astronomical Union) is
88
the stars stay in “fixed” positions on the celestial sphere because they
Are so far away that our eyes don’t notice their motions through space
The celestial sphere is
A useful illusion/imaginary sphere used to map the stars and other objects in the sky
Which of the following statements about the celestial sphere is not true
The “celestial sphere” is just another name for our universe
What is the ecliptic
the Sun’s apparent annual path around the celestial sphere
On the celestial sphere, the Sun
circles once each year along the path called the ecliptic
You experience night-time when
You are located on the side of the Earth that faces away from the Sun.
Why do we experience night and day on Earth
Earth rotates on its axis once every 24 hours
We can describe the position of an object in our local sky by stating its
Altitude and direction
How many arcminutes are in 1°
60
How many arcseconds are in 1 arcminute
60
How many arcseconds are in 1°
3600
If you hold your fist at arm’s length, you will see it spanning an angle of about
10°
We can describe the location of a point on Earth’s surface by stating its
Latitude and longitude
Is there any place on Earth where we can see stars rise in the west and set in the east (rather than rising in the east and setting in the west)? Why or why not
No, because the rising and setting of stars is caused by Earth’s west to east rotation
If it is midnight in New York, it is
daytime in Sydney, Australia
What is a circumpolar star
A star that always remains above your horizon
Circumpolar stars remain above your horizon at latitudes
True
What makes the North Star, Polaris, special
It appears very near the north celestial pole
You are standing on Earth’s equator. Which way is Polaris, the North star
On the northern horizon
By locating the north celestial pole (NCP) in the sky, how can you determine your latitude
The altitude of the NCP is the same as your latitude
If you see Polaris directly overhead, you must be very close to
The North Pole.
You are standing at the North Pole. Which way is Polaris, the North star
Directly overhead
Seasons on Earth are caused by
tilt of Earth’s axis.
When it is summer in the Northern Hemisphere, it is ________ in the Southern Hemisphere
Winter
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
The Northern and Southern hemispheres have equal illumination from the Sun
On the March and September equinoxes
Suppose that Earth’s rotation axis were tilted by 45 degrees instead of 23.5 degrees. Which ofthe following would be true, and why
The seasons would be more extreme, because the Sun’s rays would be more direct in summer and less direct in winter
Why is January a cold month in the northern United States
the northern hemisphere is tilted away from the sun
Which of the following is not the name of one of the phases of the Moon
half moon
We say that the Moon is gibbous when
It appears to be more than half illuminated, but not full
Which of the following statements about the Moon is not true
The Moon is visible in our sky only at night
Why are lunar eclipses more commonly seen than solar eclipse
Earth casts a bigger shadow than the Moon
When only part of the Moon is covered by Earth’s full shadow (umbra), we see a(n)
Partial lunar eclipse
If a solar eclipse occurs when the Moon is relatively far from Earth, so that its full shadow(umbra) does not reach Earth, then people directly behind the full shadow will experience
An annular eclipse
During a lunar eclipse, the Moon’s phase must be
Full
During a solar eclipse, the Moon’s phase must be
New
Which of the following objects was not recognized as a planet in ancient times?
Neptune
Choose the answer that fills in the three blanks in the correct order: Earth rotates once each________, Earth orbits the Sun once each ________, and the Moon orbits Earth about once each _____
Day, year, month
The reason we do not see stars in the daytime is because
The sky is too bright
