Astronomy 150 – Midterm Name:February 4, 2010 – Winter 2010 TA’s Name & Section (2 pts):Answer all questions in the space provided. If you have any questions, raise your hand.100 points possible. NO CALCULATORS OR ANY ELECTRONIC DEVICES.1 (3 pts) Which of the following characteristics of the Moon is the best evidence that the Moon has beenextensively heated?(a) Mass of the moon(b) Moon orb it inclination(c) Lack of volatiles(d) Lack of iron core(e) Oxygen isotopes like the Earth2 (3 pts) Which of the following features on Mars is most likely to have an age of about 3.8 billion years?(a) The Hellas giant impact basin(b) The Tharsis shield volcanic region(c) The landing site of Viking I on the Northern Plains(d) The South Pole CO2ice(e) The salt-rich rocks at the Opportunity site3 (3 pts) The d istance between the Earth and Moon is increasing. This leads to(a) A shorter day on the Earth(b) A longer day on the Earth(c) A increase of th e tilt of the Earth’s axis(d) A decrease of the tilt of the Earth’s axis4 (3 pts) The impact of a 10km asteroid on the Earth is especially deadly due to(a) The large shock wave sent through the interior of the Earth(b) The melting of materials at the impact site(c) The fact that it makes dinosaurs particularly angry(d) The interaction of the ejected material and the Earth’s atmosphere(e) The ejected material buried large land masses5 (3 pts) The image on the left shows two different orbits. Compared to orbitA (solid line), the orbit B (d ashed line) has a ...(a) shorter period and a larger variation in orbital speed(b) longer period and a larger var iation in orbital s peed(c) shorter period and a smaller variation in orbital speed(d) longer period and a smaller variation in orbital speed6 (8 pts) Impact breccia is very common on the Moon’s surface. Explain how this type of rock was formedand describe the source of energy that was used in its formation.7 (8 pts) Would you expect a world with a surface made of water ice to have a similar secondary atmosphereas a world with a surface made of rock? Why or Why not?8 (8 pts) Explain why the Apollo lunar samples are key to determining the age of the surface of Mercury.9 (8 pts) Explain why rocks found on th e rims of impact craters are generally older than rocks found fartheraway.10 (8 pts) Volcano es on Venu s released a lot of water into the early atmosphere of Venus. There is no waterin the current atmosphere of Venus. Explain what happened to the water in Venus’ atmosphere.11 (3 pts) When did most of the surface of the Moon we see today actually form? Be specific.12 (3 pts) When did most of the surface of Venus we see today actually form? Be specific.13 (6 pts) Explain why your weight would change if you increased the size of the E arth, without changingthe mass of you or the Earth. Would you r weight increase or decrease?14 (2 pts) What is the density of a world that is composed mostly of rock with a little iron mixed in?15 (3 pts) Describe how the Moment-of-Inertia factor of a world changes as it differentiates.16 (8 p ts) Explain why it is unlikely that a Moon-sized world , 0.5 AU from the Sun, would have anatmosphere.17 (8 pts) Describe (in words) the relative numb er of different sized craters on a typical mare su rface onthe Moon.18 (10 pts) In the space below, sketch a possible phase diagram for a substance with the following charac-teristics:1. It is solid at room temperatur e and room pressure.2. It is liquid when the temperature and pressure are each twice what they are in this room.3. It is gaseous when the temperature and pressure are one half what th ey are in this room.4. Make sure to label your