Chapter 21 Final

Alpha Centauri is a famous star because it is one of the closest stars to earth (other than the sun of course). Where would you look in the night sky for Alpha Centauri?

Look for the brightest star in the constellation Centaurus.

At the beginning of spring, the vernal equinox, what is the right ascension of the sun?

0

When Earth is the farthest from the Sun, it is said to be in the perihelion position.

False

The first scientist to use a telescope for astronomical purposes was ________.

Galileo

This scientist was the first to use the telescope in astronomy.

Galileo

Why do the planets "drift" east relative to the stars and then move west for periods of time?

They are moving in the same rotation sense as the earth around the sun, but as the earth moves faster (or slower, depending on the planet) the motion appears to be backwards.

A statement you will sometimes hear people say is that a day is not 24 hours but is really 23 hr. 56 min. and 4 sec. What does this refer to?

This is sidereal time, not solar time; a solar day is 24 hours.

You are studying a constellation of stars and need to rank the stars in order of brightness. Which of the following Greek letters would be used to note the brightest star?

alpha α

The earliest astronomical records appear to have been made by the ancient Chinese, Egyptians, and Babylonians in order to ________.

determine when to plant crops or hunt animals based on seasonal changes

One of the discoveries which led to the modern view of the solar system was that the orbits of the planets are ________.

ellipses

When viewing the planets, Mars appears to move backwards, or retrograde, because ________.

it is rotating around the sun slower than the earth's rotation

A total eclipse of the Sun is only possible at ________.

new moon

What is the modern explanation for "guest stars" that appear in the night sky and then disappear?

stars that go Nova or Supernova and appear as bright objects during the event

The period of time required for the Moon to complete a cycle of phases is called the ________ month.

synodic

Galileo observed several features using the telescope. Which one of the following did he not discover?

the two moons of Mars