12/21/12 12:22 AMHW#6 - Jovian Systems and Asteroids & Comets (Chapters 8 & 9)Page 13 of 43http://session.masteringastronomy.com/myct/assignmentPrintView?assignmentID=1301156Which of the following best explains why Jupiter’s density is higher than Saturn's?Hint 1. How does mass affect density?Suppose that two planets have the exactly the same composition but very different masses. Which statement will be true?ANSWER:ANSWER:CorrectBecause Jupiter and Saturn have nearly identical composition, Jupiter’s higher density indicates that its interior is more compressed thanSaturn’s. This greater compression is due to gravity, which is stronger for Jupiter because of its greater mass.Part EBased on the leading scientific theory of solar system formation, which of the following statements best explains why Uranus and Neptune have asignificantly different composition and higher density than Jupiter and Saturn?Hint 1. How did the jovian planets form?Which of the following best describes the leading model for the formation of the jovian planets?ANSWER:ANSWER:As long as the compositions are the same, both planets will have equal density.The more massive planet will have lower density.The more massive planet will have higher density.Jupiter is closer to the Sun than Saturn.Jupiter has a stronger magnetic field than Saturn.Jupiter has a higher proportion of hydrogen compounds and rock than Saturn.Jupiter is more massive than Saturn.Accretion built solid planetesimals of rock and ice with about 10 times the mass of Earth, and the gravity of these planetesimalsthen pulled in hydrogen and helium gas from the surrounding nebula.Huge balls of gas formed from the solar nebula, which then differentiated so that heavier ingredients sunk to the center while lightergases escaped into space.Each planet formed with a composition that reflected the general composition of the solar nebula at its particular distance from theSun.Jupiter and Saturn formed closer to the Sun, where there was more hydrogen and helium gas and less hydrogen compounds and rock.Jupiter and Saturn captured more gas from the solar nebula than Uranus and Neptune.
Now consider the second major characteristic (two types of planets). Which of the following statements are true? Check all that apply. Jovian planets are higher in average density than terrestrial planets. Jovian planets orbit farther from the Sun than terrestrial planets. Jovian planets have more moons than terrestrial planets. Jovian planets are larger in size than terrestrial planets. Jovian planets are larger in mass than terrestrial planets. The solar system contains vast numbers of small bodies, which we call asteroids when they are rocky and comets when they are icy. These small bodies are concentrated in the region(s) of the solar system that we call __________. Check all that apply. the comet belt the solar corona the Doppler belt the Kuiper belt the Oort cloud the asteroid belt All the following statements are true. Which of them are considered to be "exceptions" to the general trends described by the first three major characteristics of the solar system? Check all that apply. Pluto is in the outer solar system but is ice-rich in composition. Our Moon has a diameter more than 1/4 the diameter of Earth. Jupiter's largest moon, Ganymede, is even larger than Earth's moon. Uranus rotates with an axis tilt that lies nearly in the ecliptic plane. Venus rotates in a direction opposite to the rotation of the other terrestrial planets. Consider only the observed patterns of motion in the solar system. Scientifically, which of the following possible conclusions is justified from the patterns of motion alone? The planets were born from a giant cloud of gas that rotated in the same direction that the Milky Way Galaxy rotates. The planets were not each born in a separate, random event. The planets were not born within the past million years, but instead they must have been born billions of years ago. The planets started out quite small and grew to their current sizes as they gradually accreted more material. Now consider why the observed patterns of motion lead to the conclusion that the planets were not born in separate, random events. The reason for this conclusion is that, if the planets had been born in separate, random events, we would expect that __________.