Astronomy Chapter 2 Concept Questions
About how many stars are visible to the naked eye on a clear, dark night away from city lights?
-A couple thosand
You observe a full moon rising at sunset. What will you see at midnight?
-A full moon high in the sky
Which correctly describes the meridian in your local sky?
-A half-circle extending from your horizon due north, through your zenith, to your horizon due south.
We cannot see a new moon in our sky because...
-A new moon is quite near the sun in the sky.
Stars that are visible in the local sky on any clear night of the year, at any time of the night are called...
-Circumpolar
During the period each year when we see Mars undergoing apparent retrograde motion in our sky, what is really going on in space?
-Earth is catching up with passing by Mars in their respective orbits.
For most of history, the lack of observable stellar parallax was interpreted to mean that...
-Earth is stationary at the center of the Universe.
Each choice below describes how a few astronomical phenomena are related to time periods. Which list is entirely correct?
-Earth's rotation defines a day. The cycle of the Moon's phases takes about a month. Earth's orbit defines a year. Earth's cycle of axis procession takes 26,000 years.
Lunar eclipses can occur only during...
-Full moon
When traveling north from the United States into Canada, you'll see the North Star(Polaris) getting...
-Higher in the sky.
If we have a new moon today. when will we have the next full moon?
-In about 2 weeks.
How does Earth's varying distance from the Sun affect our seasons?
-It doesn't, Earth's orbital distance plays no significant role in the seasons.
What is stellar parallax?
-It is the slight back-and-forth shifting of star positions that occurs as we view the stars from different positions in Earth's orbit of the Sun.
Suppose you use the Southern Cross to determine that the south celestial pole appears 40 degrees above your horizon. Then you must be located at...
-Latitude 40 degrees south.
We describe a location on Earth's surface by stating its...
-Latitude and longitude.
An angle of 1 arcsecond is...
-Less than he thickness of a human hair held at arm's length.
Suppose it is full moon. What phase of Earth would someone on the Moon see at this time?
-New Earth
In any particular place on Earth, certain constellations are visible in the evening only at certain times of the year because...
-Our evening view of space depends on where Earth is located in its orbit around the Sun.
During the time that a planet is in its period of apparent retrograde motion:
-Over many days or weeks, the planet moves westward relative to the stars, rather than the usual eastward relative to the stars.
What statement about the celestial sphere is NOT true?
-The "celestial sphere" is another name for our universe.
Suppose you see a photo showing Jupiter half in sunlight and half in shadow (that is, a first quarter Jupiter). This photo might have been taken by...
-The Galileo spacecraft that orbited Jupiter in the 1990s.
If you are located in the Northern Hemisphere, which of the following correctly describes a relationship between the sky and your location?
-The altitude of the north celestial pole equals your latitude.
What statement does not use the term angular size or angular distance correctly?
-The angular distance between those two bright stars in the sky is about 2 meters.
What is the celestial sphere?
-The celestial sphere is a representation of how the entire sky looks as seen from Earth.
If our year were twice as long (that is, if Earth took twice as many days to complete each orbit around the Sun), but Earth's rotation period and axis tilt were unchanged, then...
-The four seasons would each be twice as long as they are now.
Suppose Earth's axis tilt was significantly greater than its current 23.5 degrees, but Earth's rotation period and orbital period were unchanged. What statement would not be true?
-The length of each season (for example, the number of days from the summer solstice to the fall equinox) would be significantly longer than it is now.
The moon always shows nearly the same face to Earth because...
-The moon rotates once in the same amount of time that it takes the moon to orbit Earth once.
All of the following statements are true. Which one explains the reason there is not a solar eclipse at every new moon?
-The orbital plane of the Moon is tilted slightly (by about 5 degrees) to the ecliptic plane.
What do we mean when we talk about the Milky Way in our sky?
-The patchy band of light that outlines he plane of the Milky Way Galaxy as seen from Earth.
What is the ecliptic?
-The path the Sun appears to trace around the celestial sphere each year.
The Sun's path, as viewed from the equator, is highest in the sky on...
-The spring and fall equinoxes.
What is the best way to describe why we have seasons on Earth?
-The tilt of Earth's axis causes different portions of the Earth to receive more or less direct sunlight at different times of the year.
The point directly over your head is called...
-The zenith
It's 6am and the Moon is at its highest point in the sky (crossing the meridian). What is the Moon's phase?
-Third Quarter
Suppose you are facing north and you see the Big Dipper close to your northern horizon, with Polaris (and the Little Dipper) above it. Where will you see the Big Dipper in six hours?
-To the right of Polaris; That is, 90 degrees counterclockwise from its current position.
The Andromeda Galaxy is faintly visible to the naked eye in the constellation Andromeda. Suppose instead it were located in the same direction in space as the center of the Milky Way Galaxy (but still at its current distance). How would it appear to the eye in that case?
-We could not see it at all.
Suppose you live in the United States and you see a crescent moon in your evening sky tonight. What will a friend in South America see tonight?
-Your friend will also see a crescent moon.
What do astronomers mean by constellation?
A constellation is a region in the sky as seen from Earth.
What is the saros cycle?
The roughly 18-year cycle over which the pattern of eclipses repeats.