Astronomy- Chapter 2
If you know that Venus is going to be visible, at what time and where in the sky would you look for it?
(Just before sunrise) to the east; (just after sunset) to the west
Which was the Greek figure most responsible for introducing mathematical explanations of natural phenomena?
Pythagoras
Describe how each celestial object moves through the sky (w/ regard to the equator and poles)
Rise in the east, set in the west, parallel to the equator, around the celestial poles
Suppose you go out at sunset and see Jupiter just rising over the eastern horizon. Where will it be at sunrise?
Setting in the west
You observe a full moon just rising in the east. What time of day is it?
Sunset
Why did the Greeks believe the Earth is flat?
THEY DIDN'T
A star is located at declination 30.0 degrees. You latitude is 45.0 degrees. What is the angle between the star and the zenith?
15 degrees
How long is a sidereal month?
27 days
How long is a synodic month?
29 days
While driving at sunset, you see the Moon high in the sky, with the eastern face bright. What phase is the moon?
3rd quarter (you are looking toward south)
If the moon rose in the east last night at 5:00 pm, what time will it rise tonight?
5:50 pm
True or false: planets change their locations relative to the background stars from night to night.
True
True or false: planets remain near the ecliptic.
True
True or false: planets vary in brightness over the course of a year.
True
True or false: the lower the sun appears in the sky, the higher the latitude it is at.
True
At what time of day might the moon rise when it is in the waxing crescent phase?
About 9 am
At what time of day does the moon rise above the horizon when it is in the 3rd quarter?
About midnight
What astronomical objects always appears near the ecliptic?
Anything in our solar system
Where must you be standing to see Polaris?
Anywhere in the Northern Hemisphere
From which locations on Earth are the same constellations above the horizon at all times of the year?
At the celestial poles
Which was the earliest ancient civilization known to have observed and recorded the positions of the planets over long periods?
Babylonians
Suppose you take a snapshot of the night sky at dusk this evening. At what time would you have to observe the sky 6 months from now in order to find the stars in exactly the same position in the sky?
Dawn (12 hour difference)
A resident in the Northern Hemisphere measures the length of daylight every day for a year. What day is the shortest?
December 21
What were the 4 terrestrial elements according to Aristotle?
Earth, water, air, and fire
While a planet is undergoing retrograde motion, what direction does it move through the sky?
East to West
While a planet is undergoing normal action, what direction does it move through the sky?
East to west
While a planet is undergoing retrograde motion, what direction does it move relative to the stars?
East to west
What causes seasons?
Experiencing more direct illumination from the sun and experiencing longer days during summer than winter
True or false: planets occasionally move west to east across the sky during a single night.
False
If an observer on Earth views a new moon, in what phase would an observer on the moon view Earth to be?
Full
You observe a lunar eclipse. In what phase must the moon be in?
Full
You observe the sun at noon from the U.S on June 21 and December 21. When is the sun higher in the sky, and when is the sun lower in the sky?
Higher in June, lower in December
Which astronomer was responsible for developing the stellar magnitude system still in use today?
Hipparchus
A resident in the Southern Hemisphere observes the Sun's position at noon every day over the course of a year. On what day will the Sun be lowest in the sky?
June 21
From the Northern Hemisphere, on which date is the Sun the highest in the sky?
June 21
Suppose 2 of your friends hold identical boxes. The 1st is standing 2m away, and the 2nd is standing 10m away. The closer box occupies a ___________ angle than the 2nd. By how much?
Larger; 5x
During the month of September, the constellation Aries is high in the sky at midnight. At what time of year is Aries high in the sky at noon?
March (6 month difference)
You observe a solar eclipse. In what phase must the moon be in?
New
Ptolemy's formulation provided the 1st successful set of accurate predictions for what?
The celestial motion of the planets
What is it that causes the synodic month to be about 2 days longer than the sidereal month?
The earth is orbiting the sun
What do we call the Sun's path across the celestial sphere over the course of a year?
The ecliptic
What is the ecliptic?
The path the sun takes through the stars
What is the zodiac?
The set of 12 constellations that lie along the ecliptic
Why did the Greeks reject a heliocentric model of the universe?
There was an apparent lack of periodic movement of any stars
If you observe the moon to be a full moon tonight, what will it be in 3 days?
Waning gibbous
While a planet is undergoing normal action, what direction does it move relative to the stars?
West to east
If a star is at zenith, what is it's declination?
Your latitude
