Exam 2: Users Guide to the Sky: Patterns and Cycles

Which of the following best describes the Big Dipper?

What is the celestial equator?

As the Earth rotates, circumpolar stars appear to move counterclockwise around the north celestial pole.

The second is defined as a fixed interval of time, with no reference to astronomical timescales. If the Earth's period of rotation doubled, but its period of revolution stayed the same, what would happen?

What is the sidereal period of the Moon?

Why are Venus and Mercury often called "morning star" and "evening star"?

The seasons are caused by the precession of the Earth's axis.

Suppose Earth orbited half as far from the Sun but that the size of the Moon and its orbit around Earth were the same as they are today. Which of the following statements would be true?

The constellation of Orion is currently visible in the evenings in January. Precession will not affect this, and 13,000 years from now Orion will still be visible in January.

You look at a time exposure photograph of the night sky taken in the northern hemisphere and notice that each circumpolar star traces one-eighth of a complete circle around Polaris. What was the exposure time for the photograph?

Which of the following best defines the ecliptic?

What is the term for a solar eclipse in which the Moon's umbra does not reach the Earth's surface?

Which of the following is 18 years and 11-1/3 days long?

When and where is a waxing crescent Moon visible?

Which of the following measures time relative to the stars?

____________________ is a measure of the light energy that hits one square metre in one second.

What language is the source of most star names, such as Aldebaran and Betelgeuse?

An observer in the northern hemisphere takes a time exposure photograph of the night sky. If the illustration depicts the photograph taken by the observer, which direction was the camera pointing?

-The diagram shows three approximate locations of the Sun along the western horizon. Which number indicates the location of the Sun at sunset on June 21 (summer solstice) for an observer at a latitude of 77° North?

An observer in the southern hemisphere takes a time exposure photograph of the night sky. If the illustration depicts the photograph taken by the observer, which direction was the camera pointing?