Astronomy Exam 2 (Section 11)

Questions and Answers

What does Mercury have?

almost no atmosphere

Which of the following planets can be said to have almost no atmosphere?

Venus

Mercury (correct)

Mars

Earth

The presence of frozen water on Mercury is?

possible because it has no axial tilt so that its poles never face the Sun

What is expected about the temperature at the poles of Mercury?

Very hot all of the time on mountain peaks hit by the Sun and very cold all of the time in craters never hit by the Sun Signup and view all the answers

How long does a solar day on Mercury last?

two complete orbits around the Sun Signup and view all the answers

Relative to the distant stars, how many rotations does Mercury complete each time it orbits the Sun?

1.5 rotations Signup and view all the answers

What is the magnetic field of Mercury about?

1% of the Earth's magnetic field Signup and view all the answers

Which of the following planets has a magnetic field whose intensity is about 1% of the intensity of the Earth's?

Mercury Signup and view all the answers

What does the current model for the way that planets acquire magnetic fields require?

rotation and a core that contains a liquid electrical conductor Signup and view all the answers

According to the currently accepted model, what must a rotating planet with a substantial magnetic field contain?

a liquid electrical conductor Signup and view all the answers

The number of moons of Mercury is?

0 Signup and view all the answers

Which of the following planets had no moons at all?

Mercury Signup and view all the answers

Space probes often visit several planets before getting to their final destinations. The main reason they do this is to?

reduce the amount of fuel needed because they can slingshot Signup and view all the answers

What is the main purpose of gravitational slingshot maneuvers used by space probes?

change the direction and speed of the probe without using rockets Signup and view all the answers

What was the first space probe to reach the planet Mercury?

Mariner 10 Signup and view all the answers

Mariner 10 was the first space probe to reach which planet?

Mercury Signup and view all the answers

What was the second space probe to reach the planet Mercury?

MESSENGER Signup and view all the answers

As of 2008, how many successful space probes have visited Mercury?

two (Mariner 10 and MESSENGER) Signup and view all the answers

What kind of atmosphere does Venus have?

an atmosphere of carbon dioxide with about 90 times the surface pressure of Earth's Signup and view all the answers

Which of the following planets has an atmosphere with about 90 times the surface pressure of Earth's?

Venus Signup and view all the answers

The presence of frozen water on Venus is?

impossible because every part of it is too hot for water ice Signup and view all the answers

Which of the following planets had the highest surface temperature?

Venus Signup and view all the answers

What is notable about Venus's rotation?

Venus rotates backwards so that the Sun rises in the West Signup and view all the answers

Relative to the distant stars, Venus completes how many rotations each time it orbits the Sun?

less than one full rotation Signup and view all the answers

What is the magnetic field of Venus like?

essentially zero Signup and view all the answers

Which of the following planets has no magnetic field of any kind?

Venus Signup and view all the answers

The number of moons of Venus is?

0 Signup and view all the answers

Which of the following planets has no moons at all?

All of the above Signup and view all the answers

The first space probes to land on another planet were from the?

Russian Venera series Signup and view all the answers

The Russian Venera 9 space probe was sent to Venus, where it?

landed on the surface and took pictures Signup and view all the answers

Which of the following space probes made detailed three-dimensional maps of Venus using radar from orbit around the planet?

Magellan Signup and view all the answers

As of 2008, how many successful space probes has Venus been visited by?

about 20 Signup and view all the answers

Which of these is a distinctive feature of the Earth's atmosphere?

It permits all three phases of water Signup and view all the answers

Which of the following planets or moons has an atmosphere whose temperature and pressure permit all three forms of water?

Earth Signup and view all the answers

Earth's orbit is currently?

elliptical enough to make the intensity of sunlight vary by 6 percent Signup and view all the answers

At present, the distance from the Earth to the Sun changes enough to make the intensity of sunlight vary by?

6 percent Signup and view all the answers

What do Milankovich cycles refer to?

changes in the intensity of sunlight due to shifts in both the Earth's orbit and rotation axis Signup and view all the answers

What causes Milankovich cycles?

changes in the intensity of sunlight due to shifts in both the Earth's orbit and rotation axis Signup and view all the answers

The Earth's magnetic field plays an essential role in?

protecting the Earth from charged particles from the Sun Signup and view all the answers

Our Sun sends out intense streams of charged particle radiation. The radiation is prevented from hitting the Earth's atmosphere by?

the Earth's magnetic field Signup and view all the answers

How large is the Earth's moon compared to Earth?

1/4 the size of Earth Signup and view all the answers

The Lunar Maria are actually?

ancient lava flows Signup and view all the answers

Ancient lava flows on the Moon are called?

Maria Signup and view all the answers

What do the dark markings on the Full Moon that make up the face of the 'Man in the Moon' refer to?

Lunar Maria Signup and view all the answers

The number of Maria on the side of the Moon facing away from the Earth is?

less than on the side facing the Earth Signup and view all the answers

The side of the Moon that faces away from the Earth has?

only a few small lunar Maria Signup and view all the answers

The circular structures on the surface of the Moon are a result of?

impacts Signup and view all the answers

How often does the Moon rotate on its axis relative to the distant stars?

once every sidereal month Signup and view all the answers

The Moon rotates on its axis so that it always keeps?

the same side toward the Earth Signup and view all the answers

What is the magnetic field of the Earth's Moon like?

essentially zero Signup and view all the answers

Does the Moon's orbit suggest it formed along with the Earth?

yes, that is one reason we do not think that it formed along with the Earth Signup and view all the answers

The key argument against the Moon's forming from the Earth alone, by breakup of a single object, is that the Moon's?

orbit is tilted relative to the Earth's equator Signup and view all the answers

The statement that lunar material is much 'dryer' than Earth material refers to the absence of?

hydrated minerals Signup and view all the answers

Hydrated minerals on the Moon are?

almost completely absent Signup and view all the answers

The currently accepted theory of how the Moon formed is the?

collision theory Signup and view all the answers

The first successful soft landing on the Moon was?

Surveyor 1 in 1966 Signup and view all the answers

The first human landing on the Moon was?

Apollo 11 in 1969 Signup and view all the answers

Mars has an atmosphere of?

carbon dioxide with about 1% the surface pressure of Earth's Signup and view all the answers

What is the range of temperature on Mars?

similar to those in Antarctica Signup and view all the answers

In the surface environment of Mars, water exists?

mostly as ice and water vapor Signup and view all the answers

Mars has a solar day that is?

very close to an Earth day in length Signup and view all the answers

Which of these planets has a solar day that is very close to an Earth day in length?

Mars Signup and view all the answers

Mars's orbit is currently?

elliptical enough to make the intensity of sunlight vary by 40 percent Signup and view all the answers

At present, the distance from Mars to the Sun changes enough to make the intensity of sunlight vary by?

40 percent Signup and view all the answers

What is the magnetic field of Mars like?

essentially zero Signup and view all the answers

Which of the following objects has no overall magnetic field except for small regions due to magnetized ore deposits?

Mars Signup and view all the answers

The number of moons of Mars is?

2 Signup and view all the answers

Which of the following planets has just two moons?

Mars Signup and view all the answers

Which of these moons rises in the west as seen from its primary planet?

Phobos Signup and view all the answers

Which of the following planets has a moon that rises in the west?

Mars Signup and view all the answers

Which spacecraft went into orbit around Mars only to find the surface totally obscured by a planet-wide dust storm?

Mariner 9 Signup and view all the answers

Mariner 9 was an early space probe sent to orbit?

Mars Signup and view all the answers

The first soft landing on Mars was led by the?

Viking landers Signup and view all the answers

Viking 1 and 2 were sent to explore?

the planet Mars Signup and view all the answers

Which of the following was the spacecraft that operated in Mars orbit for nine years, finding traces of water and an early magnetic field?

Mars Global Surveyor Signup and view all the answers

What was the first space probe to test the air-bag landing system?

Pathfinder Signup and view all the answers

Pathfinder was the first to use airbags to land on?

Mars Signup and view all the answers

The first space probe to place a robotic rover on the surface of Mars was?

Pathfinder Signup and view all the answers

Pathfinder was the first to place a robotic rover on the surface of?

Mars Signup and view all the answers

Study Notes

Mercury

Almost no atmosphere, making it the planet with the least atmospheric presence.
Presence of frozen water possible due to lack of axial tilt, preventing poles from facing the Sun.
Temperature extremes: Very hot on sunlit mountain peaks, very cold in permanently shaded craters.
Has a unique solar day lasting two Mercury orbits around the Sun, resulting in 1.5 rotations per orbit.
Magnetic field is roughly 1% of Earth's, requiring a liquid electrical conductor and rotation for generation.
Mercury has no moons, being one of the only two planets (along with Venus) without any.

Venus

Has a thick atmosphere comprised of carbon dioxide, with pressure approximately 90 times that of Earth's.
Surface temperature is the highest among all planets.
Frozen water is impossible on Venus due to excessively high temperatures.
Rotates in the opposite direction; the Sun rises in the West.
Magnetic field intensity is essentially zero, and the planet has no moons.

Earth

Hosts an atmosphere allowing all three phases of water (solid, liquid, and gas).
Orbit variations cause changes in sunlight intensity up to 6%.
Milankovich cycles explain long-term climate changes linked to Earth's orbital shifts.

The Moon

Earth's moon is about 1/4 the size of Earth, unusually large for a natural satellite.
Lunar Maria are ancient lava flows, with fewer visible on the far side of the Moon.
The moon has minimal magnetic field and its surface is largely devoid of hydrated minerals.
The collision theory explains the Moon’s formation rather than simultaneous formation with Earth.

Mars

Mars has a thin atmosphere composed mainly of carbon dioxide, with a pressure about 1% of Earth's.
Surface temperatures resemble those found in Antarctica, with water existing mainly as ice or vapor.
Solar day on Mars closely mirrors Earth's in duration and has an elliptical orbit that significantly varies sunlight intensity.
Mars hosts two moons, Phobos and Deimos, with Phobos rising in the west as seen from the planet.
Notable missions include Mariner 9, which ended up obscured by dust storms, and Viking landers which achieved the first soft landing on Mars.

Space Exploration

Space probes utilize gravitational slingshot maneuvers to save fuel by altering speed and direction without rockets.
The first to reach Mercury was Mariner 10, followed by MESSENGER.
Venus has been visited by around 20 successful probes, with the Venera series making the first landings.
Mars has been explored by multiple missions, including Mars Global Surveyor, which detected traces of water and early magnetic fields, and Pathfinder, which demonstrated airbag landing and deployed a robotic rover.

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Test your knowledge of Mercury and its unique characteristics in this astronomy exam flashcard set. This quiz covers aspects such as its atmosphere, temperature, and presence of frozen water. Perfect for students studying planetary science and celestial dynamics.