ASTR 2003 H Test 2 2/27/2003 Version 1 1. The volume of Mars is about ___ that of the Earth. (a) 1/2 (b) 1/4 (c) 1/8 (d) 1/16 2. The Earth is about ___ the size of the Sun. (a) 1/10 (b) 1/20 (c) 1/50 (d) 1/100 3. The oldest rocks in the solar system are meteorites. (a) true (b) false - some lunar breccias are older (c) false - Pluto's surface is older 4. At the center of the Earth is (a) solid rock (b) liquid rock (c) solid metal (d) liquid metal. 5. Tectonic plates usually move a few _____ per year. (a) mm (b) inches (c) yards (d) miles 6. Due to tidal forces, the Moon's orbit is expanding and the Earth's (a) orbit is contracting (b) orbit is expanding (c) spin is speeding up (d) spin is slowing down. 7. The Moon orbits the Earth in about a (a) day (b) week (c) month (d) year. 8. The craters on the Moon are volcanic in origin. (a) true (b) false - tectonic in origin (c) false - formed by impacts 9. The Moon contains essentially no (a) basalt (b) breccia (c) regolith (d) iron. 10. Mercury spins ___ time(s) per orbit. (a) 1/2 (b) 2/3 (c) 1 (d) 3/2 11. The orbit of Venus is (a) prograde (b) retrograde (c) highly eccentric (d) distorted. 12. The surface of Venus is about ____ K. (a) 500 (b) 750 (c) 900 (d) 1200 13. The polar caps on Mars are almost pure CO2. (a) true (b) false 14. The Viking landers found (a) no signs of life (b) only very primitive bacteria (c) simple plants (d) small plants and animals. 15. How big is Phobos? (a) 1 mile (b) 20 miles (c) 100 km (d) 200 km 16. How many moons does Jupiter have? (a) 6 (b) 12 (c) 18 (d) 32 17. Saturn is mainly made of (a) hydrogen (b) helium (c) silicate rock (d) basalt. 18. The core of Jupiter contains mainly (a) iron (b) basalt (c) solid helium (d) liquid metallic hydrogen. 19. The core of Jupiter spins (a) faster than the Earth (b) slower than the Earth. 20. How many giant planets have rings (a) 1 (b) 2 (c) 3 (d) 4 (e) 5 21. How many Galilean moons are there? (a) 2 (b) 3 (c) 4 (d) 5 (e) 6 22. The rings of Saturn are made of (a) rock or dust (b) glass (c) ice (d) hydrogen. 23. The rings of Neptune are made of (a) rock or dust (b) glass (c) ice (d) hydrogen. 24. How many moons are known to have atmospheres? (a) 0 (b) 1 (c) 2 (d) 3 (e) 4 25. We have now discovered Earth-like planets orbiting nearby Sun-like stars. (a) true (b) false 26. _________ is about 1/2 the size of Pluto. (a) Earth's moon (b) Charon (c) Ganymede (d) Phobos (e) Titan 27. Oort-cloud comets do not orbit the Sun. (a) true (b) false 28. Halley's comet is a (a) long-period comet (b) escaped moon of Pluto (c) non-trapped comet (d) trapped comet. 29. The nucleus of Halley's comet is about ___ km in size. (a) 10 (b) 100 (c) 1000 (d) 10000 30. Comets were born in the Oort cloud, very far from the Sun. (a) true (b) false 31. Meteors, or "shooting stars," are typically the size of (a) a grain of sand (b) a bread box (c) a refrigerator (d) a small car (e) a house. 32. The most common meteorites to fall are the (a) irons (b) stony-irons (c) stony type (d) achondrites. 33. Most meteorites are pieces of (a) comets (b) planets (c) moons (d) asteroids. 34. Most asteroids are found near (a) Mercury and Venus (b) Pluto and Neptune (c) Uranus and Neptune (d) Mars and Jupiter. 35. Some asteroids have little moonlets. (a) true (b) false 36. The Sun's core is at a temperature of _____ K. (a) a few thousand (b) tens of thousands (c) a million (d) 15 million (e) 52 million 37. Because of mixing, the Sun's surface and core have the same chemical composition. (a) true (b) false 38. Sunspots are associated with (a) aurorae (b) fusion reactions (c) magnetic fields (d) spicules. 39. Suppose 2002 was a year of sunspot maximum. The next such occurrence will be in (a) 2007 (b) 2013 (c) 2020 (d) 2024 (e) 2050. 40. Suppose that in 2002 the Sun's North Pole had north magnetic polarity. The next such occurrence will be in (a) 2007 (b) 2013 (c) 2020 (d) 2024 (e) 2050. 41. Granulation is a surface manifestation of (a) conduction (b) radiation (c) convection (d) fusion (e) fission. 42. A loop of hot solar gas is a (a) spicule (b) prominence (c) aurora (d) corona (e) filament. 43. Matter from the Sun streams through (a) solar plages (b) solar spicules (c) photospheric gaps (d) coronal holes. 44. The Moon's shadow on the Earth is never bigger than a few (a) miles (b) tens of miles (c) hundred miles (d) thousand miles. 45. There are no partial lunar eclipses. (a) true (b) false 46. During a total solar eclipse, stars near the Sun appear shifted ______ the Sun. (a) toward (b) away from 47. Gas pressure depends on the _____ of the gas. (a) mass (b) size (c) radioactivity (d) temperature 48. Due to conservation of _______, a contracting gas cloud spins faster. (a) angular momentum (b) energy (c) mass (d) potential energy 49. Magnetic braking explains the current ______ of the Sun. (a) mass (b) size (c) momentum (d) spin 50. The chemical composition of a planetary body depends mainly on the _______ at which it formed. (a) temperature (b) density (c) time