Plasma Tailthe Nucleusthe Comathe Multiple Choice

4 PointsWhat is Eris?

1. an icy object that orbits in the Kuiper belt and is larger than Pluto
2. the largest known asteroid
3. a moon of Pluto
4. an extrasolar planet ejected by another solar system and captured by ours

4 PointsWhat is a meteorite?

1. a small moon that orbits one of the giant planets
2. a streak of light caused by a star moving across the sky
3. a comet that burns up in Earth’s atmosphere
4. a streak of light caused by a small particle from space burning up in Earth’s atmosphere
5. a fragment of rock of an asteroid from the solar system that has fallen to Earth’s surface

4 PointsWhen a comet passes near the Sun, part of it takes on the appearance of a large, bright ball from which the tail extends. This part is called ________.

1. the plasma tail
2. the nucleus
3. the coma
4. the Oort core

4 PointsWhich of the following statements about comets and asteroids is true?

1. Most of the trillions of comets in our solar system have tails.
2. Only asteroids collide with Earth.
3. There are about 1 million known asteroids in the solar system.
4. Comets are balls of ice and dust.
5. All asteroids lie in the asteroid belt between Mars and Jupiter.

4 PointsPluto is most like a

1. jovian (gas giant) planet.
2. terrestrial planet.
3. star.
4. comet.

4 PointsPlanetary rings are

1. known to exist for all of the jovian planets.
2. All of these
3. orbiting in the equatorial plane of their planet.
4. composed of a large number of individual particles that orbit their planet in accord with Kepler’s third law.

4 PointsHow is Jupiter’s magnetic field?

1. it does not have
2. weak
3. strong

4 PointsWhich of the following best explains why many jovian moons have been more geologically active than the Moon or Mercury?

1. The jovian moons probably have far more internal heat generated by radioactive decay than do the Moon or Mercury.
2. Jovian moons are made mostly of ice that can melt or deform at lower temperatures than can the rock and metal that make up the Moon and Mercury.
3. The jovian moons are considerably larger than the Moon and Mercury and therefore have retained much more internal heat.
4. Because of their greater distances from the Sun, the jovian moons receive much less heat from the Sun.

4 PointsWhy does Jupiter have several distinct cloud layers?

1. Winds prevent clouds from forming at some altitudes, so we see clouds only at the other altitudes.
2. Different layers represent clouds made of gases that condense at different temperatures.
3. Clouds form randomly, so on average there are always several layers.
4. Different gases are present at different altitudes in Jupiter’s atmosphere.
5. Different layers represent the various regions where the temperature is cool enough for liquid water to condense.

4 PointsAccording to current understanding, which of the following is required in order for a planet to have rings?

1. The planet must be at least as massive as Saturn.
2. The planet must orbit its star at a distance greater than Mars orbits the Sun.
3. The planet must once have had a large moon that came too close to it, shattering the moon and creating the ring particles.
4. The planet must have many small moons that orbit relatively close to the planet in its equatorial plane.

4 PointsWhat’s the fundamental reason that Mars, unlike the Earth, has become virtually geologically dead?

1. its large size compared to the Earth
2. its closer distance than Earth to the Sun
3. its farther distance than Earth to the Sun
4. its small size compared to Earth
5. its slow rotation compared to the Earth
6. its rapid rotation compared to the Earth

4 PointsFrom center to surface, which of the following correctly lists the interior layers of a terrestrial world?

1. mantle, core, crust
2. core, crust, lithosphere
3. mantle, crust, core
4. core, mantle, crust

4 PointsWhy does the burning of fossil fuels increase the greenhouse effect on Earth?

1. Burning produces infrared light, which is then trapped by existing greenhouse gases.
2. Burning releases carbon dioxide into the atmosphere.
3. Burning fuel warms the planet.
4. All of these are true.
5. Burning depletes the amount of ozone, thereby warming the planet.

4 PointsWhich of the following can act like a long-term “thermostat” for the Earth’s average temperature?

1. heat stored in the Earth’s liquid core
2. heat stored in the Earth’s magnetosphere
3. radioactive elements trapped in the Earth’s mantle
4. the carbon dioxide cycle

4 PointsVenus has a thicker atmosphere than Earth.

1. True
2. False

4 PointsAccording to our theory of solar system formation, why do we find some exceptions to the general rules and patterns of the planets?

1. The exceptions probably represent objects that formed recently, rather than early in the history of the solar system.
2. The exceptions probably represent objects that were captured by our solar system from interstellar space.
3. Our theory is not quite correct because it cannot explain these exceptions.
4. Most of the exceptions are the result of giant impacts or close gravitational encounters.
5. The exceptions exist because, even though our theory is as correct as possible, nature never follows rules precisely.

4 PointsAccording to our theory of solar system formation, what are asteroids and comets?

1. chunks of rock or ice that were expelled from planets by volcanoes
2. the shattered remains of collisions between planets
3. leftover planetesimals that never accreted into planets
4. chunks of rock or ice that condensed after the planets and moons finished forming

4 PointsIn essence, the nebular theory holds that ________.

1. nebulae are clouds of gas and dust in space
2. The nebular theory is a discarded idea that imagined planets forming as a result of a near-collision between our Sun and another star.
3. the planets each formed from the collapse of its own separate nebula
4. our solar system formed from the collapse of an interstellar cloud of gas and dust

4 PointsWhich planet (besides Earth) has been visited by the largest number of robotic spacecraft?

1. Mars
2. Jupiter
3. Saturn
4. Venus

4 PointsWhat is the giant impact hypothesis for the origin of the Moon?

1. The Moon formed just like the Earth, from accretion in the solar nebula.
2. The Moon formed when two gigantic asteroids collided with one another.
3. The Moon formed from material blasted out of the Earth’s mantle and crust by the impact of a Mars-size object.
4. The Moon originally was about the same size as Earth, but a giant impact blasted most of it away so that it ended up much smaller than Earth.

4 PointsWhat do we mean by the interstellar medium?

1. the name of an oracle who can channel messages from beings that live near the star called Vega
2. the gas and dust that lie in between the stars in the Milky Way galaxy
3. the middle section of the Milky Way galaxy
4. the dust that fills the halo of the Milky Way galaxy

4 PointsEnergy balance in the Sun refers to a balance between ________.

1. the rate at which fusion generates energy in the Sun’s core and the rate at which the Sun’s surface radiates energy into space
2. the mass that the Sun loses each second and the amount of mass converted into energy each second
3. the amount of energy the Sun radiates into space and the amount of energy that reaches Earth
4. the force of gravity pulling inward and the force due to pressure pushing outward

4 PointsHow do disk stars orbit the center of the galaxy?

1. They follow spiral paths along the spiral arms.
2. They have orbits randomly inclined and in different directions relative to the galactic center.
3. They all orbit in roughly the same plane and in the same direction.
4. They follow orbits that move up and down through the disk, typically taking them about 50,000 light-years above and below the disk on each orbit.

4 PointsWhy do sunspots appear dark?

1. They are composed of different elements than the rest of the sun.
2. They are thick clouds on the sun, blocking its light.
3. They are regions that are significantly cooler than the rest of the photosphere.
4. They are regions nearly devoid of gas.

4 PointsWhat do sunspots, solar prominences, and solar flares all have in common?

1. They are all shaped by the solar wind.
2. They are all strongly influenced by magnetic fields on the Sun.
3. They all have about the same temperature.
4. They all occur only in the Sun’s photosphere.