Within the frost line, bits of rock and metal clumped together to make planetesimals. By measuring the amount of its decay product (argon-40) present in the rock, you realize that there must have been 72 grams of potassium-40 when the rock solidified. The frost line marked an important dividing point in the solar nebula. What would be your best estimate of that planetary system's age?The age of the solar system can be established by radiometric dating ofWhich of the following does the solar nebular theory not predict?Which of the apparent exceptions to the solar nebular theory cannot be explained by a giant impact event?the orbit of Triton in the opposite direction to Neptune's rotationThe heavy bombardment phase of the solar system lastedAccording to our theory of solar system formation, why do we find some exceptions to the general rules and patterns of the planets?Most of the exceptions are the result of giant impacts or close gravitational encounters.Which of the following are relatively unchanged fragments from the early period of planet building in the solar system?Observations of young stars (as well as theory) tell us that when the Sun was young, the solar windWhat kind of material in the solar nebula could condense at temperatures as high as 1,500 K, such as existed in the inner region of the nebula?What percentage of the mass of the solar nebula consisted of elements other than hydrogen and helium?What percentage of the solar nebula's mass consisted of hydrogen and helium gases?According to our theory of solar system formation, why do all the planets orbit the Sun in the same direction and in nearly the same plane?The laws of conservation of energy and conservation of angular momentum ensure that any rotating, collapsing cloud will end up as a spinning disk.As the cloud shrank, its gravitational potential energy was converted to thermal energy.What can we conclude from the fact that Neptune's large moon Triton orbits in a direction opposite to the direction in which Neptune rotates?Which of the following is not a characteristic of the outer planets?On average, a cupful of which planet would weigh the least?Which planet has the most extreme temperature difference between day and night?Which planet could an astronaut visit without the need for a spacesuit (and survive)?None; an astronaut would need a spacesuit to survive a visit to any other planet in the solar system.Which of the following observations indicates that Mars had a warmer, thicker atmosphere in the past?Which planet has the highest average surface temperature, and why?Venus, because of its dense carbon dioxide atmosphereHow does the Sun's mass compare with that of the planets?It is about a thousand times more massive than all the planets combined.According to modern scientific dating techniques, approximately how old is the solar system?According to our theory of solar system formation, what are asteroids and comets?leftover planetesimals that never accreted into planetsWhat do we mean by accretion in the context of planet formation?the growth of planetesimals from smaller solid particles that collided and stuck togetherWhat 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.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; metalAccording to our theory of solar system formation, what three major changes occurred in the solar nebula as it shrank in size?It got hotter, its rate of rotation increased, and it flattened into a disk.Why would we expect to find a higher percentage of heavy elements in a young star, as opposed to an older star?Heavy elements are produced by stars living and dying, so more heavy elements get incorporated into future generations of stars.When we say that jovian planets contain significant amounts of hydrogen compounds, we mean all the following chemical compounds except ________.In essence, the solar nebular theory states that ________.our solar system formed from the collapse of an interstellar cloud of gas and dustWhich planet (besides Earth) has been visited by the largest number of robotic spacecraft?The Cassini mission to Saturn consists of ________.an orbiter that orbits Saturn and a probe that descended to the surface of TitanWhich moons are sometimes called the Galilean moons?the four largest moons of Jupiter: Io, Europa, Ganymede, and CallistoWhich of the following statements does not apply to the formation of gas giants like Jupiter, compared to terrestrial planets?The terrestrial planets are made almost entirely of elements heavier than hydrogen and helium.