Chapter 21 & 22

________ is the principal gas in the Venusian atmosphere and also a minor component of the atmospheres of Earth and Mars.

Carbon Dioxide

________, a moon orbiting Jupiter, has an unusually smooth, uncratered, ice-covered surface.

Europa

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

Galileo

Galileo believed in a ________ view of the universe.

Heliocentric

Earth is closest to the Sun in ________.

January

There is evidence of water on ________.

Mars

Of the terrestrial planets, ________ exhibits the greatest lateral variations in surface temperatures.

Mercury

The largest known volcano in the solar system is ________.

Olympus Mons on Mars

Which of the following is not a Jovian planet?

Pluto

Where will the North Star be, relative to the celestial coordinates, 12,000 years from now?

Several degrees from the North Pole position, and Vega will be the North Star instead of Polaris.

Which of these men formulated the Law of Universal Gravitation?

Sir Isaac Newton

Earth hits its perihelion position in January. Solar radiation is proportional to the distance squared between the Sun and the earth, so why isn't it hot in "winter" at perihelion?

The ellipticity of the orbit is small, so the affect is small; seasons are caused by tilt of Earth's orbit.

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.

In the Ptolemaic (Greek) model of the universe, the stars are attached to the ________.

celestial sphere

The angular distance north or south of the celestial equator is called ________.

declination

Pluto is now classified as a ________ in our solar system.

dwarf planet

Solar eclipses are ________ lunar eclipses.

less common than

Kepler said that the ________ go(es) around the ________ on ________ orbits.

planets; Sun; elliptical

The ________ side of the Moon is always visible from Earth.

same