- If the Earth rotated in the opposite sense (clockwise rather
than counterclockwise), how long would the solar day be? -
Suppose that the Earth’s pole was perpendicular to its orbit.
How would the azimuth of sunrise vary throughout the year? How
would the length of day and night vary throughout the year at
the equator? at the North and South Poles? where you live? - You
are an astronaut on the moon. You look up, and see the Earth in
its full phase and on the meridian. What lunar phase do people
on Earth observe? What if you saw a first quarter Earth? new
Earth? third quarter Earth? Draw a picture showing the geometry.
- If a planet always keeps the same side towards the Sun, how
many sidereal days are in a year on that planet? - If on a given
day, the night is 24 hours long at the North Pole, how long is
the night at the South Pole? - On what day of the year are the
nights longest at the equator? - From the fact that the Moon
takes 29.5 days to complete a full cycle of phases, show that it
rises an average o