Astronomy 150 - Midterm Name:October 26, 2000 TA’s Name & Section (2 pts):Answer all questions in the space provided. If you have any questions, raise your hand. 100points possible.-1 (3 pts) Water has a density of g/cm3, rocks have a density of about g/cm3and iron has adensity of g/cm3.0 (4 pts) Write down the equation that describes the force of gravity between you and the Earth [be sureto say what your variables mean].Four planets are orbiting a star that is identical to our Sun. From the Earth we observed these planets andcollected the following data:Planet Mass Diameter Density [g/cm3] Average Distance[Earth = 1] [Earth = 1] Compressed Uncompressed from star [AU]Kenny 0.20 0.50 8.0 8.0 0.5Kyle 0.50 0.75 6.0 5.0 0.8Stan 1.0 1.0 5.0 4.0 1.0Cartman 4.0 2.0 2.5 1.0 3.01 (2 pts) Which of the planets takes the shortest time to orbit around the star?2 (3 pts) How long does it take the planet Stan to orbit the star [show your work]?3 (4 pts) If we assume that these planet are made of the same materials as our solar system (ice, rock andiron) what is the most likely compositions of the planet Kenny?4 (4 pts) What is the most likely composition of the planet Stan?5 (4 pts) Which of the planets is most likely the least geologically active? [Explain your answer].6 (5 pts) The planet Cartman is larger and more massive than the Earth. However, you would weigh thesame on Cartman as you would on the Earth. Explain why this is [show your work].You are part of the team of scientists that is sent to explore this planetary system. As you approach thesystem you measure the properties of the atmospheres the these planets.Planet Surface Pressure Surface Temperature Composition[atm] Range [◦C]Kenny . . . -100 – 300 No AtmosphereKyle 0.1 0 – 200 96% CO2, 4% N2Stan 1.0 10 – 50 95% CO2, 5% N2Cartman 10.0 90 – 110 98% CO2, 2% N27 (6 pts) The planet Cartman is further away from the central star than Stan is, yet it has a higher surfacetemperature and a smaller range in temperatures. Explain how this can be.8 (6 pts) Explain why it is unlikely than any of these planets have any Earth-like plant life on their surfaceseven though some of the planets have warm, thick atmospheres.101.00.10100 200Pressure (atm)SolidTemperature (C)LiquidGasScientists on the Earth have proposed that a substancecalled GUNK may be found on the surfaces of some of theplanets. On the left is a phase diagram for GUNK.9 (4 pts) On the surface of Kyle, GUNK can existin all three states. On Kyle the boiling point of GUNK is[◦C] and the freezing point is [◦C].10 (4 pts) Before you arrived in the planetary system, it was theorized that large seas of GUNK may existon the surface of the planet Stan. Based on the data you collected so far, explain if this is possible?11 (5 pts) On the surface of Cartman, GUNK can only exist as a gas. However, clouds of liquid GUNKwere detected in the atmosphere. Explain how this can be.CCDBAAED12 (5 pts) From orbit around Cartman you createthe geological map of a possible landing site. Indicatethe relative ages of the various landforms from oldest(1, formed first) to youngest (5, formed last).A - Cratered TerrainB - Lava FlowC - Sinuous RilleD - Straight Rille (Fault)E - Crater and Ejecta13 (5 pts) You notice from your mapping that even on the cratered terrain there are no craters smaller thanabout 10 km. Explain why this may be.14 (5 pts) How would you determine the absolute age of the Cratered Terrain?After landing on the surface of Cartman the first thing you is walk to the rim of the crater [E] collectingrocks. Back in the lab you determine what type of rocks you found. Your results are shown in the table onthe below.0m100m50mABDCRock Distance from Rock Rock AgeRim (meters) Type [million yrs]A 0 Basalt 20B 25 Basalt 10C 50 Basalt 10D 75 Breccia 215 (6 pts) Most of the rocks you found around the crater were basalts. We have seen basalt or basalt-likerocks on every world so far. Describe what basalt looks like and how it is formed.16 (2 pts) Look at the geological map on the previous page. What landform is the most likely origin of thebasalts you found?17 (5 pts) I said that an impact crater evacuates material from a maximum depth of about 1/10 the craterdiameter. Assume that crater [E] is 1000 meters in diameter. Is the lava flow that crater [E] fell on greateror less than 100 meters thick? [Explain your answer]18 (6 pts) Look at the age of the rocks you collected. Explain why they get older as you get closer to therim.19 (6 pts) You analyze the rocks at your landing site and find that they are rich in heavy elements likeplatinum and iridium. Why should such heavy elements be rare in the crust of the planet Cartman.20 (4 pts) What is the most likely origin of these heavy elements?If you drop your keys in molten lava just let ’em go ’cause man,they’re gone.– Deep Thoughts by Jack Handey