The second exam is on Friday, May 14. It will cover chapter 4 sections 3-6, chapters 5,6,7 and chapter 8 section 1. it will also cover the material we discussed regarding the human influence on global climate change. Also, there will be a few questions about light and spectroscopy.

The list below is not intended to be a complete study guide, but rather to assist you in recalling the different topics and concepts that were covered. I don't recommend simply downloading the lectures and studying straight off of them alone.

Make sure you know that light-years (LY) are the units for distance in astronomy!!!!!

Review list for Physics 101 Exam 2

Chapter 4

• the origin of the atmosphere and oceans: the water came in as ice and hydrated minerals in objects that condensed further away from the Sun in the solar nebula. after these objected were incorporated into the proto-earth, these rocks melted in the intense heat of the newly-formed earth, releasing their water in a process called outgassing, forming the atmosphere and oceans.
• what do we mean by a geologically old vs. younger terrain?
• relative ages of planetary surfaces from cratering
• the period of heavy bombardment ended about 3. 8 billion years ago
• why the moon and mercury are heavily cratered but earth is not
• impact sterilization of the early earth. life may have begun and been wiped out numerous times from 4.5 to 3.8 billion years ago
• continental crust vs. seafloor crust
• internal energy source of the earth, why earth is not geologically dead but the moon and mars do seem to be
• mantle convection as the force driving plate tectonics
• subduction of the seafloor and how it factors into regulation of climate via the carbon dioxide cycle
• Snowball earth
• the greenhouse effect, what causes it and why it is a good thing
• human-induced climate change: global warming - what causes it and why it is a bad thing ... know the three solid facts about human induced global climate change. see p106-107

Chapter 5

• Miller-Urey experiment
• how is DNA a "living fossil"?
• the rise of oxygen in the earth's atmosphere
• photosynthesis released oxygen
• cyanobacteria are thought to be a very primitive form of life, perhaps the oldest form of life existing on earth today
• eukaryotes are thought to have evolved as simpler organisms (bacteria, archea) joined in a process called symbiosis: making a more complex organism from simpler ones
• support for endosymbiosis is found today in the form of chloroplasts, which are photosyntheetic organelles in all plant cells. also, alpha proteo bacteria are identical to mitochondria of animal cells.
• the cambrian explosion
• the extinction of the dinosaurs! Ka-BOOM! Know the lines of evidence supporting the impact theory of the KT extinction
• there have been 5 mass extinctions. hve they all been caused by impact?
• the impact hazard today
• know the general idea behind the evolution diagrams shown in Fig. 5-22.

Chapter 6

• why do we focus our search for life by studying life on earth? it is the only example we have, and we need to direct our search. it's not because of lack of imagination, or assuming everyone else must be just like us!
• environmental requirements for life
• inverse square law for the amount of light a planet gets from its parent star. what is the Habitable Zone and why is it so narrow.
• why water is a great liquid and others aren't that great, as far as life is concerned.
• how do we learn about other worlds? collect samples (meteorites or via sample-return missions such as apollo and stardust), or collect light with a telescope
• telescopes: spectra vs. images.
• what is resolution? how do we get better resolution images/spectra?
• ways of improving images: interferometry, get above the atmosphere, larger collecting area, adaptive optics
• why do we think that the Moon, Mercury, Jupiter, and other bodies in the solar system are not likely to support life?
• why is Mars thoguht to be a place where life once existed, or may even exist still today?

Chapter 7

• what is mars like today? compare to earth, and certain environments on earth
• what causes the seasons on earth? I PROMISE I WILL ASK YOU THIS ON THE TEST! :-)
• what causes the seasons on mars, and how is this different than for earth?
• similarities and differences between mars and earth: think dust storms, polar ice caps, atmosphere (amount, composition, etc), geology
• evidence for water environments in Mars' distant past
• comparing martian geology to earth's: river valleys and catastrophic flood channels
• climate history of mars. why does Mars' climate seem to change so much? (because it's tilt changes chaotically over millions of years). why doesn't earth's change quite so much? (Because we have a large moon, which keeps our tilt relatively steady)
• searching for life on Mars: results of the Viking biology experiments
• martian meteorites: the question of "evidence for life" in ALH84001
• why do we go to antarctica to search for meteorites?
• new results from the Mars exploration rovers. They carry microscopic imagers unlike the other mars missions in the past. microscopic data are consistent with the idea that water was present at Mars' surface in the distant past.

Chapter 8

• there will be a kepler's law problem with Jupiter's moons. If I give you P and a of one moon, you can use those to find the a of another, if you also know P of that other moon. P^2/a^3 of Io = P^2/a^3 of Europa, for instance. Galileo showed that they obey Kepler's third law.
• know what tides are, what causes them on earth, and what causes them on europa.
• how is the internal energy source of Io different from earth? (hint: know that tidal heating, and tidal friction are)
• what does tidally locked mean? (it is also called synchronous rotation)
• why are the mountains and volcanoes on Io so big compared to those on earth?