AST -Chap 9

Volcanic activity on Venus is thought to be:

less frequent, but more violent than volcanic activity on Earth

Our most detailed maps of Venus come from:

the Magellan spaceprobe

Because of its slow rotation period, Venus:

presents the same side to Earth at each closest approach.

The surface of Venus can be observed with:

radar observations from Arecibo.

What is the composition of the clouds of Venus?

sulfur and sulfuric acid droplets

Venus' full phase occurs when Venus is at:

superior conjunction

The absence of a magnetic field on Venus probably stems from its:

slow rotation.

Venus is only a little bit (5%) smaller than Earth, and its density is only slightly less than Earth's. Therefore, its mass is:

just a little bit less than Earth's.

Magellan did not find which of these on Venus?

actual volcanic eruptions in progress

Venus has a feature named Aphrodite Terra. What is this feature?

a continental-sized plateau

What resonance exists between Venus' rotational period and its synodic period?

5:1, with the Earth always closest to the same side of Venus when they pass

What is thought to have caused the craters on Venus?

Most are volcanic in origin; some are due to meteoritic impacts.

Comparing the clouds of Earth and Venus, we find that:

ours lie in the troposphere, within 10 kilometer of our surface, but Venus has a higher troposphere, with its clouds about 40 kilometers high.

The main problem spacecraft have encountered in landing on Venus is:

the extremely high temperatures.

What percentage of the surface of Venus could be characterized as continental-sized highlands?

less than 10%

Which statement is true of Venus' surface?

There are two continent sized uplands.

The largest volcanic structures on Venus are called:

coronae.

Maxwell Mons on Venus is a huge:

shield volcano.

At closest approach Venus is about how far from Earth?

0.3 AU

Why is it reasonable to conclude that the internal structure and evolution of Venus are basically Earthlike?

They have similar masses and sizes.

Venus orbits the Sun in 225 days. How long does it take to rotate on its axis?

243 days, even though the Earth's tidal pull is not involved

If Venus once had an ocean, where did it go?

The water broke into hydrogen, which escaped to space, and oxygen, which became trapped in the planet's surface rocks.

Venus' rotation

takes longer than its orbit around the Sun.

Through radar observations it was found that Venus

rotation on its axis is retrograde.

The synodic period of Venus is the time it takes for:

Venus to complete a full cycle of phases

Earth and Venus are often called sister planets; in which ways are they most alike?

size, density, and surface gravity