Review for Exam 3 Chapters 9-14 PHYS 1050 May 2002 N. B. Errors in the Key of Test #2 resulted in a 4 point correction that will be applied to each student’s score for the 2nd test Purpose • This document is a study guide, NOT a comprehensive list of all topics included on the exam. • The exam will cover material from both the text, class notes, and class demonstrations. • SUMMARY and REVIEW AND DISCUSSION at the end of the text chapters are also good sources of information and comprehension assessment. Equations and Constants • True size distance x angular size – diameter/(2 x distance) = angular diameter/360o • F = ma • Fgrav = Gm1m2/r2 • P2 = a3 • (M+m) P2 = a3 • circumference of circle = 2 x radius = 2 r • area of circle = r2 • volume of sphere = 4/3 r3 • diameter = 2 x radius OR D = 2r • density = mass/volume • distance = speed x time • 3600 in a circle •VENUS – Appearance and motions of Venus as viewed from Earth. • Venus is an inferior planet and never moves more than 47o from the Sun. • Are phases observed (like for the Moon) ? • Why is Venus the third brightest object in the sky (after Sun and Moon)? – Review basic properties of Venus (p. 207), especially unusual properties. • Compare to Earth: mass, size, density, surface temperature, seasons, satellites,rotation rate, and orbital period. – Basic structure of atmosphere. • composition, surface density compared to Earth • nature and location of cloud layers • temperature profile, average surface temperature – Understand how the greenhouse effect has changed Venus. – Does Venus have a magnetosphere? Why or why not? – Basic large-scale topography • relatively smooth surface of mostly rolling plains. • ~8% of surface “continents” • No oceans/ice deposits. Why? – Surface structures known from radar maps. • volcanic, meteor impact craters, evidence for plate tectonics, global geologic activity. – History of exploration: spacecraft and information provided. – Compare spheres on Venus to those of other terrestrial planets and Earth’s Moon. •MARS – Appearance and motions of Mars as viewed from Earth. • Mars is a superior planet. How does it appear to move in the sky? • Why does Mars appear red to an Earth-bound observer? – Review basic properties of Mars (p. 225), especially unusual properties. • Compare to Earth: mass, size, density, surface temperature, seasons, satellites, rotation rate, orbital period, magnetosphere. – Atmosphere • composition, surface density compared to Earth • nature and location of cloud layers, weather, dust storms • average surface temperature (day/night) and relationship to thickness of atmosphere • Does the greenhouse effect operate in the Martian atmosphere? Explain. – Large-scale topography and surface features • N-hemisphere contrasted to S-hemisphere: craters, age, elevation, geology. • Olympus Mons, Valles Marineris, Tharsis bulge, polar ice caps. – Small-scale topographic features discovered by Mariner, Viking, Mars Global Surveyor. • impact craters with fluid ejecta, runoff and outflow channels, sand dunes • relationship to geologic properties of surface, presence of water, weather changes – Two small moons, Phobos and Deimos. Compare/contrast to Earth’s Moon. – Has evidence for life on Mars been found? Possibility of life under surface? – Compare spheres to those of other terrestrial planets and Earth’s Moon. – Exploration from space: Mariner, Viking, Mars Global Surveyor, Mars Odyssey. •Jupiter – Appearance of Jupiter as viewed from Earth. • Describe Jupiter’s appearance through a telescope. What are you seeing? • Which constellations does Jupiter move through? How often does it pass from one to another? • How bright is Jupiter compared to other solar system objects? – Review basic properties of Jupiter (p. 281). • Compare to Earth/Sun: mass, size, density, composition, rotation rate, orbital period, magnetosphere. – Atmosphere • Composition: atmosphere and clouds • What are the belts and zones in atmosphere? (relative temperature & elevation) • What is the Great Red Spot? • What are the ovals, barges, loops and eddies? • List three factors that contribute to atmospheric features observed. • Compare to features in Earth’s atmosphere. – Internal structure • Is there a solid surface to the planet? • Describe the inferred internal structure. • What is at the core? Site evidence for inference. •Jupiter (continued) – Jupiter radiates twice as much energy as it receives from the Sun. • What is the source of this “excess” heat ? – Moons • Understand the basic properties of the four, large Galilean moons. –order from planet –relative sizes and densities (compared to Earth’s Moon) –unique features » (volcanoes, sub-surface ocean, largest size, magnetic field, etc.) – Magnetosphere • Driven by rapid rotation and inferred metallic hydrogen layer near core. • Unique aurora torus associated with Moon Io. • Sea of energetic, charged particles that are hazardous to people and electronics. – Ring system • Appearance and location wrt moons. • Discovery – History of exploration: spacecraft and information provided. – In 1994, comet Shoemaker-Levy crashed into Jupiter’s atmosphere. • Only recorded occurrence of such an event. •Saturn –Appearance of Saturn as viewed from Earth. •Describe Saturn’s appearance through a telescope. What are you seeing? –Review basic properties of Saturn (p. 308). •Compare to Earth/Jupiter: mass, size, density, composition, rotation rate, orbital period, magnetosphere. –Atmosphere •What is the composition of the atmosphere? How does it compare to Jupiter? •Are there belts and zones in atmosphere? •What is the composition of the clouds in Saturn’s atmosphere? •What are the spots sometimes seen in the atmosphere? •Compare wind speed and structure to that of Jupiter. –Internal structure: compare to Jupiter. –Saturn radiates more energy than it receives from the Sun. •What is the source of this “excess” heat ? •Saturn (continued) –Rings •What are the rings? (composition, particle size, separation) •How were they discovered? •What is believed to be the origin of the rings? •What causes some of the structure observed in the rings? (e.g., Cassini Division produced by gravitational influence of small moon) •Understand meaning of “Roche limit” •Relationship to tidal forces, ring formation. – Moons •Large moon: Titan – atmosphere – possible surface material •Medium-sized moons – properties of surfaces – icy compositions – History of exploration: spacecraft and information provided. •Uranus –Edge of visibility without optical aid. •Who discovered Uranus? When? How? •What color does Uranus appear to be? Why is it that color? –Review basic properties of Uranus (p. 332). •Compare to Earth/Jupiter: mass, size, density, composition, rotation rate, orbital period. –Uranus’ rotation axis tilted 98o from normal to orbital plane. •How does this affect the “seasons” on Uranus? –Atmosphere •Uranus appears to bland when compared to other jovian planets. Why? •Compare its composition and clouds to Jupiter/Saturn and Neptune. –Interior Structure •Compare to Jupiter/Saturn and Neptune. •Excess energy? •Magnetic field size, orientation, generation. •Uranus –System of narrow, rope-like rings discovered around Uranus in 1970’s. • How were they detected? •What are they made of? • Why are they not immediately visible through a telescope, as are Saturn’s rings? –Moons •Describe the moon system about Uranus. • Are there any large moons? • How do the mid-sized moons compare to the mid-sized moons of Saturn? –History of exploration: • spacecraft and information provided. •Neptune –Cannot be seen without a telescope. •Who discovered Neptune? When? •Neptune’s existence was predicted, then confirmed. –Review basic properties of Neptune (p. 341). •Compare to Earth: mass, size, density, composition, rotation rate, orbital period. –Describe the appearance of Neptune by telescope and as imaged by spacecraft. •Why does Neptune appear so blue in color? –Atmosphere •Compare its composition and clouds to Jupiter/Saturn and Uranus. •Storms, zonal flow, belts and zones? –Interior Structure •Compare to Jupiter/Saturn and Uranus. •Excess energy? •Magnetic field size, orientation, generation. •Neptune (continued) –System of narrow rings was discovered around Neptune. •How were they detected? •What are they made of? •What is odd about their structure? –Moons •Describe the moon system about Neptune. •Are there any large moons? •Describe any unusual features or properties of these moons. –History of exploration: spacecraft and information provided. •Pluto – Cannot be seen without a telescope. • Who discovered Pluto? When? – Review basic properties of Pluto (p. 347). • Compare to Earth: mass, size, density, composition, rotation rate, orbital period. • Pluto’s orbit is tilted 17o to the ecliptic - largest value for any planet. • Pluto’s orbit has an eccentricity of 0.249 - largest value for any planet. – Describe the appearance of Pluto by telescope. – Atmosphere • Composition, seasonal variations – Pluto is not a jovian planet - it has a surface. • Describe current ideas describing this surface. • What is believed to be the overall composition and structure of this planet? • What object in the solar system does it most resemble? – Moon • Describe Pluto’s one large moon, Charon. • Describe the unusual characteristics of the Pluto/Charon system. • What are some theories for the formation and evolution of Pluto/Charon. – History of exploration: spacecraft and information provided.