Exam 22: The Earths Companions

The moon has active volcanoes and plate tectonic processes.

A compass would be useful to an astronaut lost on the moon.

____ is the most volcanically active object in our solar system at the present time.

Heat left over from this planetary formation process along with radioactive decay,drives the Earth's internal heat engine.

The moon formed from debris blasted out of Mars by an impact of an object about the size of Mercury.

To the best of our knowledge,the Earth,Sun,and Moon are all the same age,about _______ years old.

Venus and Earth have ________ surfaces and atmospheres.

A giant meteor impact crater is found in the United States near ______.

Venus's atmosphere has much more carbon dioxide than that of Earth and its greenhouse effect is much stronger.

As meteors enter the Earth's atmosphere,large numbers are slowed by air resistance and may reach the ground as smaller fragments called meteorites.

All the planets are exactly the same size.

Comets are small solid bodies of rock or iron in the outer part of our solar system.

The inner and outer planets have similar atmospheres.

____ are small,planetlike bodies.

Astronomers think that most comets come from the Oort cloud.

The four outer (giant)planets are composed largely of _______.

The largest part of a(n)______ is its long,glowing tail,a narrow column of dust that may extend for 100 million km.

Planetismals are small planet-like bodies in our solar system.

Mars is named for the Roman god of war,presumably because of its distinct _____ color when seen in the sky.

_____ is the closest moon to Jupiter of the Galilean satellites.