astronomy ch 2

When we see Saturn going through a period of apparent retrograde motion, it means

Earth is passing Saturn in its orbit, with both planets on the same side of the Sun

If the Sun rises precisely due east:

it must be the day of either the spring or fall equinox.

The North Celestial Pole is 35∘ above your northern horizon. This tells you that you are at:

latitude 35∘ N.

Two stars that are in the same constellation:

may actually be very far away from each other.

If there is going to be a total lunar eclipse tonight, then you know that:

the Moon's phase is full.

The fact that we always see the same face of the Moon tells us that

the Moon's rotation period is the same as its orbital period.

In winter, Earth's axis points toward the star Polaris. In spring:

the axis also points toward Polaris.

A week after full moon, the Moon's phase is:

third quarter

Beijing and Philadelphia have about the same latitude but very different longitudes. Therefore, tonight's night sky in these two places:

will look about the same.

When it is summer in Australia, the season in the United States is

winter.