Review Exam 2 1. Planet X has a radius 3 times larger than the earth’s radius. How does this planet’s volume compare to Earth’s volume? a. The volume is 3 times larger than the Earth’s radius. b. The volume is 1/9 the Earth’s radius. c. The volume is 27 times the Earth’s Radius. d. The volume is 1/27 times the Earth’s radius. 2. The moons X and Y orbit 2 different planets. They have the same orbital velocity, but the distance of X from its planet is 2 times the distance of planet Y from its planet. Which planet has more Mass? PLANET X 3. The Earth’s average density is 5.5 kg/L. A planet discovered orbiting another star has an average density of 3.2 kg/L. What does this tell us about this planet? e. The planet must be farther from the star than Earth. f. The planet must have a smaller mass than the Earth, so the mass per Liter is less. g. The planet must be made of a higher proportion of gases and ices than the Earth. h. The planet must have a larger volume than the Earth making the density decrease because matter is more spread out. i. The planet must be terrestrial, with lots of rock and metal. 4. Galaxy Sand and Galaxy Witch are the same distance from Earth, but the angular diameter of Sand is 2X larger. How do the physical diameter’s compare? j. Sand is ½ the diameter of Witch. k. Sand is 2x the diameter of Witch. l. Sand is ¼ the diameter of Witch. m. It cannot be determined from this information n. Sand is 8 times the diameter of Witch. 5. The Lolli Nebula and the Pop Nebula have the same angular diameter. The Pop nebula is 5 times farther than the Lolli Nebula. How do their physical diameters compare? o. Lolli is 5x smaller than Pop. p. Lolli is 25x smaller than Pop. q. Lolli is 5x larger than Pop. r. Lolli has 25x larger than Pop. 6. Planet Aladdin has an average density of 6.0 kg/L. We know that it’s surface density is about 2 kg/L. What does this tell us about the core? s. The core must be very hot. t. The core must be liquid. u. The core must be made of lower density material. v. The core must be made of much more dense material. 7. What if the densities from the last question were switched? What does that mean about the core? w. The core must be very hot. x. The core must be liquid. y. The core must be made of lower density material. z. The core must be made of much more dense material. 8. Why do the Jovian planets have so much more mass than the Terrestrial Planets? {. They are farther from the sun so the gas doesn’t float away. |. There’s more mass on the outer parts of the Protoplanetary Disk. }. There are much more ices and gases in the planetary nebula. ~. They don’t necessarily have more mass, its just gas so it is more spread out. 9. Put the Steps of Solar System Formation in Order. B, D, E, A, C . Period of Heavy Bombardment and Differentiation . Collapse of the Solar Nebula . Protostar becomes a Star . Condensation of Gases . Accretion of solid bits of material into planets 10. Protostars can only be detected using INFRARED LIGHT because Otherwise they are hidden from sight because of dust clouds.

11. Imagine that the solar system formed with the temperatures as indicated by the graph below. The graph shows that the distance from the center of the protoplanetary disk on the x-axis, and the temperature on the y-axis. The horizontal dashed line marked “water” indicates the temperature at which water would condense. If the solar system had formed with the temperatures indicated at these distances what would the planets be made of and why? ANSWER: Outer Planets are Terrestrial and the Inner Planets are Jovian. This is because the temperature is lower at the center of the protoplanetary disk in this scenario and in this case OUTSIDE the frost line actually means that it gets hotter the farther away, and so water would melt outside this water line and the outer planets would be Jovian.
ANSWER: Outer Planets are Terrestrial and the Inner Planets are Jovian. This is because the temperature is lower at the center of the protoplanetary disk in this scenario and in this case OUTSIDE the frost line actually means that it gets hotter the farther away, and so water would melt outside this water line and the outer planets would be Jovian.

12. If we find a Jovian planet inside the frost line of a star, what can we assume about its formation? Jovian Planets can only form outside the frost line, so it must have moved inward. We assume it has moved in because it could not have formed there. 13. Seismic Waves inside the Earth . Cannot travel through liquids . Travel at different speeds in materials of different densities or compositions and change direction as they move from one material to another. . Travel in straight lines with speeds that change as the waves move through materials of different densities or compositions. . Always travel in a straight line at a constant speed. 14. The Earth’s interior received its heat energy from the impacts of planetesimals and from radioactivity. This heat and energy is gradually radiating into space. As the Earth’s interior continues to cool, we can expect that, in the distant future, . The entire interior will become one homogeneous solid. . The mantle will become molten while the core will become solid. . The inner core will become molten like the outer core. . The outer core will become solid like the inner core. 15. Aurorae on the Earth are caused by . Electrical Currents in the ionosphere, generated by dynamo action in the Earth’s core . Charged particles from the Sun moving along the Earth’s magnetic field and striking the upper atmosphere. . The reflection of sunlight from arctic and Antarctic ice into the polar night skies . UV radiation from the Sun ionizing atoms in the upper atmosphere. 16. Imagine a spacecraft is sent to visit a terrestrial planet orbiting another star. The spacecraft measures that the diameter of the planet is 1.5 times the Earth’s diameter, and its average density is about 8 kg/L. It also measures that the planet’s rotation period is about 72 hours. Would you expect this planet to have a magnetic field or not? Explain your reasoning. . Two things necessary for Magnetic Field: i. Fast Rotation ii. Convection (larger planet, means more likely still hot inside and thus probably has convection) . As long as you support you answer either way would be ok. This planet is about the same size as the earth, which means it probably has convection because the heat wouldn’t have had time to escape all the way and that keeps convection going. It has a rotation period of 72. Since that is slower than earth, it is too slow rotation, so probably doesn’t have a magnetic field…. iii. OR you could say 72 hours is still pretty fast rotation so it probably has a magnetic field. (As long as you give the right reason you will be fine, no one knows the IDEAL time of rotation.) 17. Which one of the following correctly describes the locations within the Earth that have convection? . Only in the mantle . In the mantle and the outer core . Only in the outer core . In the inner and outer core . In the inner core and the mantle 18. The Earth and Venus have fewer impact craters on their surfaces than do Mars and Mercury. Why should we expect this? . Large bodies are more likely to retain an atmosphere, and thus most large projectiles burn up before striking the ground. . Large bodies actually receive more hits because of their larger size, but later craters obliterate earlier ones, and we only see evidence of the most recent. . The gravity of large bodies deflects incoming projectiles and thus there are fewer collisions. . Large bodies cool more slowly and are more likely to retain internal heat and be geologically active, capable of resurfacing the planet and obliterating craters. 19. The motion of large portions of the Earth’s surface are caused by . The varying pressure of the Earth’s atmosphere, both daily and seasonally. . Flexing of the surface due to solar heating and nighttime cooling. . Tidal forces from the Moon and the Sun, acting on continental landmasses. . Convective flow of matter in the Earth’s interior. 20. Which of the following properties accurately describe the Earth’s MANTLE? I. Mostly solid material II. Mostly liquid material III. Rocky IV. Metallic V. Has convection VI. Hottest part of the Earth’s interior . I, III, and V only . II, III, and V only . II, IV, V, and VI only . I and III only 21. The cratering which we see on the Moon is not found to the same extent on the Earth at the present time because . Plate tectonics has returned cratered surface layers into the Earth’s interior, and volcanism and erosion have obliterated the more recent craters. . All the potentially damaging interplanetary bodies were stopped by the Earth’s atmosphere. . Interplanetary objects have happened to miss the Earth during its history. . The moon protected the Earth from impacts, and this resulted in the craters on the moon. 22. Which one of the following is part of the Earth’s natural greenhouse effect? . The Earth’s surface and atmospheric gases absorb energy and then emit infrared light. . The ozone hole causes significant increases in surface temperature. . Infrared light becomes permanently trapped in our atmosphere by greenhouse gases . The Earth’s atmosphere continually becomes thicker with greenhouse gases. . Heat is transferred in the atmosphere through the circulation of greenhouse gases. 23. C. 9 W/m2 24. A 25. Stellar parallax is the . Apparent shift in the position of a nearby star because of Earth’s motion . Elliptical motion of a star in a binary system, as the two stars orbit around each other. . Assumed change in the distance of a star when it dims as it passes through an interstellar cloud . Motion of a star as it orbits around the center of our galaxy 26. If two observations of the stars Sirius and Arcturus are made at 6 month intervals, Sirius reveals a greater parallax because Sirius is . More massive than Arcturus . More distant than Arcturus . Hotter than Arcturus . Closer to us than Arcturus 27. An astronomer finds an object at a distance of 5.6 pc from the earth. Based on the distance, which one of the following is this object most likely to be? . An asteroid in our solar system . An artificial satellite orbiting the earth . A star in our galaxy . A distant galaxy 28. Sirius in Canis Major, is approximately 2.6 pc away. Vega, in Lyra, has a parallax that is about 1/3 of the parallax of Sirius. Which one of the choices below correctly states the distance of Vega? . 0.77 pc . 0.28 pc . 7.8 pc . 23 pc 29. The star Antares in Scorpius has a surface temperature of 3400 K and a parallax of 0.006 arcseconds. What is the distance of Antares? Show your work, including your original equation. Use proper scientific notations – no fractions. . D=1/parallax so 1/.006 = 1/(6x10-2) = 6x102 pc 30. The luminosity of a star is . The light emitted by 1 square meter of its surface into space at all wavelengths. . The light emitted at all wavelengths into space in all directions. . Its brightness when measured from a distance of 10 pc . Its brightness when measured from earth. 31.

Emission, through low density material, higher temp Unique wavelengths of materials, based on spectrum

32. B. Y, Z, X only look at wavelength here. Shorter wavelength, higher temperature 32. Which star has the highest surface temperature? Star A has the highest Surface Temperature, 33. A. Star L it has a HIGH temperature, but a low luminosity, so it must have a small radius.