Review Questions
Discuss how latitude and longitude on Earth are similar to declination and right ascension in the sky.
What is the latitude of the North Pole? The South Pole? Why does longitude have no meaning at the North and South Poles?
Make a list of each main phase of the Moon, describing roughly when the Moon rises and sets for each phase. During which phase can you see the Moon in the middle of the morning? In the middle of the afternoon?
What are advantages and disadvantages of apparent solar time? How is the situation improved by introducing mean solar time and standard time?
What are the two ways that the tilt of Earth’s axis causes the summers in the United States to be warmer than the winters?
Why is it difficult to construct a practical calendar based on the Moon’s cycle of phases?
Explain why there are two high tides and two low tides each day. Strictly speaking, should the period during which there are two high tides be 24 hours? If not, what should the interval be?
What is the phase of the Moon during a total solar eclipse? During a total lunar eclipse?
On a globe or world map, find the nearest marked latitude line to your location. Is this an example of a great circle? Explain.
Explain three lines of evidence that indicate that the seasons in North America are not caused by the changing Earth-Sun distance as a result of Earth’s elliptical orbit around the Sun.
What is the origin of the terms “a.m.” and “p.m.” in our timekeeping?
Explain the origin of the leap year. Why is it necessary?
Explain why the year 1800 was not a leap year, even though years divisible by four are normally considered to be leap years.
What fraction of the Moon’s visible face is illuminated during first quarter phase? Why is this phase called first quarter?
Why don’t lunar eclipses happen during every full moon?
Why does the Moon create tidal bulges on both sides of Earth instead of only on the side of Earth closest to the Moon?
Why do the heights of the tides change over the course of a month?
Explain how tidal forces are causing Earth to slow down.
Explain how tidal forces are causing the Moon to slowly recede from Earth.
Explain why the Gregorian calendar modified the nature of the leap year from its original definition in the Julian calendar.
The term equinox translates as “equal night.” Explain why this translation makes sense from an astronomical point of view.
The term solstice translates as “Sun stop.” Explain why this translation makes sense from an astronomical point of view.
Why is the warmest day of the year in the United States (or in the Northern Hemisphere temperate zone) usually in August rather than on the day of the summer solstice, in late June?