Astro Ch. 6 – Flashcards

Compared to the distance between Earth and Mars, the distance between Jupiter and Saturn is _________. - much smaller - much larger - about the same - just slightly less

How is Einstein's famous equation, E=mc2, important in understanding the Sun? - the Sun generates energy to shine by losing 4 million tons of mass each second - the Sun's surface temperature is about 6,000° Celsius - the Sun has a magnetic field strong enough to influence the atmospheres of the planets - the Sun is extremely massive

In what way is Venus most similar to Earth? - Both planets have warm days and cool nights. - Both planets have very similar atmospheres. - Both planets have similar surface geology. - Both planets are nearly the same size.

Which planet listed below has the most extreme seasons? Mars Uranus Earth Jupiter

Which of the following is not a major pattern of motion in the solar system? - The Sun and most of the planets rotate in the same direction in which the planets orbit the Sun. - All of the planets orbit the Sun in the same direction - counterclockwise as viewed from above Earth's north pole. - Most of the solar system's large moons orbit in their planet's equatorial plane. - Nearly all comets orbit the Sun in same direction and roughly the same plane.

Which of the following is not a major difference between the terrestrial and jovian planets in our solar system? - Terrestrial planets orbit much closer to the Sun than jovian planets. - Terrestrial planets contain large quantities of ice and jovian planets do not. - Terrestrial planets are higher in average density than jovian planets. - Jovian planets have rings and terrestrial planets do not.

The following statements are all true. Which one counts as an "exception to the rule" in being unusual for our solar system? - Saturn has no solid surface. - The diameter of Earth's Moon is about 1/4 that of Earth. - Venus does not have a moon. - Jupiter has a very small axis tilt.

According to our theory of solar system formation, which law best explains why the solar nebula spun faster as it shrank in size? - The law of conservation of angular momentum - Einstein's law E=mc2 - The law of universal gravitation - The law of conservation of energy

According to our theory of solar system formation, which law best explains why the central regions of the solar nebula got hotter as the nebula shrank in size? - The law of conservation of angular momentum - Newton's third law - The law of conservation of energy - The two laws of thermal radiation

According to our present theory of solar system formation, which of the following best explains why the solar nebula ended up with a disk shape as it collapsed? - It flattened as a natural consequence of collisions between particles in the nebula. - The force of gravity pulled the material downward into a flat disk. - The law of conservation of energy. - It was fairly flat to begin with, and retained this flat shape as it collapsed.

What is the primary basis upon which we divide the ingredients of the solar nebula into four categories (hydrogen/helium; hydrogen compound; rock; metal)? - The atomic mass numbers of various materials. - The amounts of energy required to ionize various materials. - The temperatures at which various materials will condense from gaseous form to solid form. - The locations of various materials in the solar nebula.

According to our present theory of solar system formation, which of the following statements about the growth of terrestrial and jovian planets is not true? - The terrestrial planets formed inside the frost line of the solar nebula and the jovian planets formed beyond it. - Swirling disks of gas, like the solar nebula in miniature, formed around the growing jovian planets but not around the growing terrestrial planets. - Both types of planet begun with planetesimals growing through the process of accretion, but only the jovian planets were able to capture hydrogen and helium gas from the solar nebula. - The jovian planets began from planetesimals made only of ice, while the terrestrial planets began from planetesimals made only of rock and metal.

Many meteorites appear to have formed very early in the solar system's history. How do these meteorites support our theory about how the terrestrial planets formed? - The meteorites appearance and composition is just what we'd expect if metal and rock condensed and accreted as our theory suggests. - Their overall composition is just what we believe the composition of the solar nebula to have been: mostly hydrogen and helium. - The meteorites sizes are just what we'd expect if metal and rock condensed and accreted as our theory suggests. - Their appearance and composition matches what we observe in comets today, suggesting that they were once pieces of icy planetesimals.

According to our present theory of solar system formation, how did Earth end up with enough water to make oceans? The water was brought to the forming Earth by planetesimals that accreted near Earth's orbit. The water was brought to the forming Earth by planetesimals that accreted beyond the orbit of Mars. The water was formed by chemical reactions among the minerals in the Earth's core. Earth formed at a distance from the Sun at which liquid water happened to be plentiful in the solar nebula.

According to our basic scenario of solar system formation, why do the jovian planets have numerous large moons? - As the growing jovian planets captured gas from the solar nebula, the gas formed swirling disks around them, and moons formed from condensation accretion within these disks. - Because of their strong gravity, the jovian planets were able to capture numerous asteroids that happened to be passing nearby, and these became the major moons of the jovian planets. - The many moons of the jovian planets remains one of the unexplained mysteries of the formation of our solar system. - The large moons of the jovian planets originally formed in the inner solar system and these moons then migrated out to join up with the jovian planets.

Which of the following is not evidence supporting the idea that our Moon formed as a result of a giant impact? - The Pacific Ocean appears to be a large crater - probably the one made by the giant impact. - The Moon has a much smaller proportion of easily vaporized materials than Earth. - Computer simulations show that the Moon could really have formed in this way. - The Moon's average density suggests it is made of rock much more like that of the Earth's outer layers than that of the Earth as a whole.

Why are terrestrial planets denser than jovian planets? - Actually, the jovian planets are denser than the terrestrial planets. - The terrestrial planets formed in the inner solar nebula, where only dense materials could condense. - The Sun's gravity gathered dense materials into the inner solar system. - Gravity compresses terrestrial planets to a higher degree, making them denser.

About 2% of our solar nebula consisted of elements besides hydrogen and helium. However, the very first generation of star systems in the universe probably consisted only of hydrogen and helium. Which of the following statements is most likely to have been true about these first-generation star systems? - There were no comets or asteroids in these first-generation star systems. - These first-generation star systems typically had several terrestrial planets in addition to jovian planets. - Like the jovian planets in our solar system, the jovian planets in these first-generation systems were orbited by rings. - Jovian planets in these first-generation star systems had clouds made of water and other hydrogen compounds.

Suppose you find a rock that contains 10 micrograms of radioactive potassium-40, which has a half-life of 1.25 billion years. By measuring the amount of its decay product (argon-40) present in the rock, you conclude that there must have been 80 micrograms of potassium-40 when the rock solidified. How old is the rock? - 1.25 billion years - 3.75 billion years - 5.0 billion years - 2.5 billion years

How do scientists determine the age of the solar system? - Radiometric dating of Moon rocks - Radiometric dating of meteorites - Theoretical calculations tell us how long it has taken the planets to evolve to their present forms - Radiometric dating of the oldest Earth rocks

Which of the following lists the planets of our solar system in the correct order from closest to farthest from the Sun? - Mercury, Earth, Venus, Mars, Jupiter, Saturn, Neptune, Uranus - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune - Earth, Mars, Mercury, Venus, Jupiter, Saturn, Uranus, Neptune - Mercury, Venus, Mars, Earth, Saturn, Jupiter, Neptune, Uranus

Which of the following statements about our Sun is not true? -The Sun is a star. - The Sun is made mostly of hydrogen and helium. - The Sun's diameter is about 5 times that of Earth. - The Sun contains more than 98% of all the mass in our solar system.

Which of the following statements about Mars is not true? - We have landed spacecraft on its surface. - It is frozen today, but once had flowing water. - It is considered part of our inner solar system. - We could survive on Mars without spacesuits, as long as we brought oxygen in scuba tanks.

The planet in our solar system with the highest average surface temperature is _________. Earth Mercury Venus Neptune

Suppose you view the solar system from high above Earth's North Pole. Which of the following statements about planetary orbits will be true? - All the planets except Uranus orbit the Sun counterclockwise; Uranus orbits in the opposite direction. - All the planets orbit counterclockwise around the Sun. - The inner planets orbit the Sun clockwise while the outer planets orbit the Sun counterclockwise. - The inner planets orbit the Sun counterclockwise while the outer planets orbit the Sun clockwise.

The terrestrial planets in our solar system are _________. - Mars, Jupiter, Saturn, Uranus, and Neptune. - Jupiter, Saturn, Uranus, and Neptune - Mercury, Venus, Earth, and Mars. - Pluto and Eris.

The jovian planets in our solar system are _________. - Pluto and Eris - Mercury, Venus, Earth, and Mars - Io, Europa, Ganymede, and Callisto - Jupiter, Saturn, Uranus, and Neptune.

When we say that jovian planets contain significant amounts of hydrogen compounds, we mean all the following chemicals except _________. methane carbon dioxide ammonia water

In essence, the nebular theory holds that _________. - each planet formed from the collapse of its own separate nebula -our solar system formed from the collapse of an interstellar cloud of gas and dust - the planets formed as a result of a near-collision between our Sun and another star. - nebulae are clouds of gas and dust in space

According to modern science, what was the approximate chemical composition of the solar nebula? - 98% hydrogen and helium, 2% everything else - Roughly equal proportions of hydrogen, helium, water, and methane - 98% hydrogen, 2% helium - 50% hydrogen and helium, 50% everything else

The terrestrial planets are made almost entirely of elements heavier than hydrogen and helium. According to modern science, where did these elements come from? - They were made by chemical reactions in interstellar gas. - They were produced by gravity in the solar nebula as it collapsed. - They have been present in the universe since its birth. - They were produced by stars that lived and died before our solar system was born.

According to our theory of solar system formation, what three major changes occurred in the solar nebula as it shrank in size? - Its mass, temperature, and density all increased. - Its gas clumped up to form the terrestrial planets, nuclear fusion produced heavy elements to make the jovian planets, and central temperatures rose to more than a trillion Kelvin. - It gained energy, it gained angular momentum, and it flattened into a disk. - It got hotter, its rate of rotation increased, and it flattened into a disk.

Which of the following types of material can condense into what we call ice at low temperatures? - Hydrogen and helium - Metal - Hydrogen compounds - Rock

According to our present theory of solar system formation, which of the following lists the major ingredients of the solar nebula in order from the most abundant to the least abundant? - hydrogen and helium gas; hydrogen compounds; rock; metal - hydrogen compounds; hydrogen and helium gas; metal; rock - hydrogen, water, methane, helium - hydrogen and helium gas; rock; metal; hydrogen compounds

What do we mean by the frost line when we discuss the formation of planets in the solar nebula? - It is a circle at a particular distance from the Sun, beyond which the temperature was low enough for ices to condense. - It is another way of stating the temperature at which water freezes into ice. - It marks the special distance from the Sun at which hydrogen compounds become abundant; closer to the Sun, there are no hydrogen compounds. - It is the altitude in a planet's atmosphere at which snow can form.

What do we mean by accretion in the context of planet formation? - The growth of the Sun as the density of gas increased in the center of the solar nebula - The solidification of ices, rocks, and metal from the gas of the solar nebular - The formation of moons around planets - The growth of planetesimals from smaller solid particles that collided and stuck together

According to our theory of solar system formation, what are asteroids and comets? - The shattered remains of collisions between planets - Chunks of rock or ice that were expelled from planets by volcanoes - Chunks of rock or ice that condensed after the planets and moons finished forming - Leftover planetesimals that never accreted into planets

What do we mean by the period of heavy bombardment in the context of the history of our solar system? - The period about 65 million years ago when an impact is thought to have led to the extinction of the dinosaurs - The time during which heavy elements condensed into rock and metal in the solar nebula - The time before planetesimals finished accreting into planets, during which many growing planetesimals must have shattered in collisions - The first few hundred million years after the planets formed, which is when most impact craters were formed

What is the giant impact hypothesis for the origin of the Moon? - The Moon formed when two gigantic asteroids collided with one another. - 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. - The Moon formed just like the Earth, from accretion in the solar nebula. - The Moon formed from material blasted out of the Earth's mantle and crust by the impact of a Mars-size object.

Suppose you start with 1 kilogram of a radioactive substance that has a half-life of 10 years. Which of the following statements will be true after 20 years pass? All the material will have completely decayed. You'll have 0.5 kilogram of the radioactive substance remaining. You'll have 0.75 kilogram of the radioactive substance remaining. You'll have 0.25 kilogram of the radioactive substance remaining.

According to modern scientific dating techniques, approximately how old is the solar system? 4.5 billion years 10,000 years 4.5 million years 14 billion years