Astronomy Chapters 9&10

The observation that began the 19th and early 20th century fascination with Mars as a place for life was:

Schiaparelli's seeing what seemed to him to be long straight features on the red planet

One of the most impressive features of the geology of Mars is an uplifted area about the size of North America, with volcanoes on it, which is called the

Tharsis Bulge

Astronomers estimate that the runoff channels seen on Mars must be at least 3.9 billion years old. How do they estimate ages like this?

by counting impact craters in the regions containing these channels

Astronomers estimate that the plains of Venus are only about 500 to 600 million years old. How do they estimate dates like this?

by counting the craters visible on the surface and comparing crater counts to other worlds

The spacecraft that sent back the most detailed radar images of Venus and showed us features as small as a football field is:

d. Magellan

Which of the following is NOT a correct statement about the rotation of Venus?

d. the rotation rate of Venus had to be determined from radar measurements

Which of the following statements about the atmosphere of Mars today is FALSE?

droplets of liquid water rain irrigate the surface of Mars regularly

The same gas makes up most of the atmosphere of Mars and Venus. This gas is:

e. carbon dioxide

The Magellan spacecraft revealed a wide variety of volcanic features on Venus, including some that looked like ticks and spiders. What instrument aboard Magellan was used for these investigations?

imaging radar

The process by which Venus became so much hotter than the Earth is called:

the runaway greenhouse effect

What is one way that we humans are currently making the atmosphere of the Earth more like that of Venus?

we are adding carbon dioxide and other greenhouse gases to the atmosphere, which is leading to global warming

The largest continental (highland) area on Venus is called:

Aphrodite

What makes astronomers believe that Mars once had rivers and running water?

Images from orbiting spacecraft reveal ancient channels that look like dried-up river beds on Earth (and our rovers show geological formations made by running water)

Why are there no smaller craters on the surface of Venus, only bigger ones?

In Venus' thick atmosphere all smaller chunks of material burn up before they can reach the surface

The first spacecraft to orbit another planet circled Mars in 1971. It was:

Mariner 9

Mars appears to have long branching channels that have the appearance of being formed by a flowing liquid. Yet we know that liquids would not stay liquid in the very thin atmosphere we have on the Martian surface? So how can we explain the channels?

Mars may have had a thicker atmosphere long ago when the channels formed

The highest mountain on Venus is also the only feature to be named after a man; its namesake is the Scottish scientist who laid the foundations for our understanding of electro-magnetic waves. This is Mount:

Maxwell

The largest volcano on Mars is called:

Olympus Mons (Mt. Olympus)

The person who really publicized the idea of canals on Mars and impressed it on the public mind was:

Percival Lowell

The spacecraft that soft-landed successfully on the surface of Venus (and briefly sent back pictures while sitting in that destructive environment) were called

Venera

There was a pair of spacecraft whose components both orbited the planet Mars and landed on its surface in 1976. These spacecraft were called:

Viking

The Viking spacecraft were designed -- in part -- to search for life on Mars. Which of the following statements about the results of these experiments is true?

Viking found that the surface of Mars in the two places it searched did not have any life or even life's building blocks

What planet can come closest to the Earth in its orbit and look brightest in our skies?

a. Venus

Which of the following is NOT a way that Venus resembles the Earth?

a. its size (diameter)

I want to examine the surface of a planet which is completely covered by a thick layer of clouds all the time. What wavelength of electromagnetic radiation would I be smartest to use:

a. visible light

Which of the following is evidence for volcanic activity on Venus?

all of the above

The planet that most resembles the Earth in size and internal composition is

b. Venus

Why does Mars have an overall reddish color when we see its surface from afar?

c. The material of Mars' surface contains a lot of iron oxide, the same chemistry that makes rusting metals look reddish

Which of the following is NOT one of the key reasons that so many spacecraft from Earth have visited Venus and Mars?

c. their atmospheres are very similar to the Earth in terms of their chemical make-up

On some parts of Mars, it gets cold enough for a gas to freeze out of the atmosphere that does not freeze out by itself at the temperatures and pressures on Earth. This gas makes up some of the polar caps on Mars and is:

carbon dioxide

A very rich and eccentric tourist in the future hires you to fly him to a region of Venus' atmosphere where the temperatures and pressures are the most Earth-like. Where would you take him?

in the cloud layers about 50 km above the surface

Astronomers believe that Mars formed with a much thicker atmosphere than it has today. Where did this atmosphere go?

it escaped into space (and some later froze out as Mars got cold)

Which of the following statements about the planet Venus is true?

it has a thick layer of clouds containing sulfuric acid droplets

Valles Marineris is a wide, deep network of chasms stretching for some 2500 miles on the surface of Mars. How do we believe such a big set of canyons formed originally?

it was caused by tectonic pressures from deep within the planet

Which of the following statements about Valles Marineris, the great "grand canyon system" on Mars is true?

landslides have helped broaden the canyons since they were first formed

The large circular coronae on Venus are:

large regions where hot magma rising from the interior of Venus puts pressure on the surface material

One way in which Mars closely resembles the Earth is:

length of its day

About 75% of the surface of Venus consists of

lowland lava plains

A crucial difference that helps explain why Venus is so hot and the Earth isn't is that:

on Venus, there was eventually no ocean to remove carbon dioxide from the atmosphere

The canals that late 19th and early 20th observers thought they saw on Mars turned out to be:

optical illusions

The troposphere (the lowest layer in the atmosphere) of Venus

resembles being about a kilometer or so under the Earth's ocean -- a huge mass of air keeps temperatures pretty much the same all over the planet

Which of the following is NOT a way we have studied the planet Mars so far?

sending spacecraft to Mars which have brought samples of the planet back to Earth

The total surface area of planet Mars is roughly equal to the

surface area of the Earth's continents

Which of the following would NOT be one of the problems faced by an unprotected Earthling stranded on Mars? (Unprotected meaning no space suit.)

the extreme (high) heat at most latitudes

Mars rovers (such as Opportunity and Curiosity) have identified evidence that their landing sites were once under water. Which of the following is among the kinds of evidence they have identified?

they found rock formations that show the area was under water and also minerals that only form in water