Astronomy Test 1 Part 1

Which ancient Greek tinker suggested(long before Copernicus) that the Earth is moving around the Sun?

Aristarchus of Samos

If the Earth goes around the Sun, why is the ecliptic not lined up with the celestial equator?

Because the Earth is tilted on an axis.

The point in the sky directly above your head at any given time is called the ___.

zenith

From horizon to opposite horizon, the sky takes up how much angular distance?

180 degrees

The great astronomer of ancient times who summarized and improved a system of circles upon circles to explain the complicated motions of the planets (and published the system in a book now called The Almagest) is: ______.

Ptolemy

As seen from the continental United States, the Big and Little Dipper _____.

are in the north circumpolar zone throughout the year

How did Eratosthenes measure the size of the Earth?

by measuring the height of the Sun in the sky on the same day in two cities at different latitudes

The 88 sectors into which astronomers today divide the celestial sphere(the whole sky) are called ______.

constellations

The celestial sphere turns once around each day because ______.

the planet is rotating

In Ptolemy's system the planets orbit the Earth and not the Sun. How did the system explain the retrograde motion of planets like Jupiter?

the planets moved on a small circle whose center in turn circled a point near the Earth

The Sun's apparent path around the celestial sphere is called _____.

ecliptic

In the Northern Hemisphere, the altitude(height in degrees above the horizon) of the North Star is always roughly equal to the ____.

latitude of the observer

The slow tipping of the Earth's axis in a circle with a period of about 26,000 years is called_______.

precession

When a planet temporarily moves westward in the sky over the course of several weeks or months (instead of eastward, as it typically does), we call it _____.

retrograde motion

The south celestial pole and the north celestial pole lie in the sky directly above the _____.

Earth's axis

The star that is currently closest to the North Celestial Pole is ______.

Polaris

Every celestial object appears to go around the Earth once a day. In addition to this motion, which celestial object has the fastest apparent motion in the sky?

The Moon.

Where on Earth do stars always circle the zenith(and never rise and set)?

The north pole

The strip of the sky through which the Sun, Moon, and bright planets appear to move in the course of a year is called ____.

The zodiac

Halfway between the celestial poles lies the _____.

celestial equator.