This will be a closed-book, closed-notes exam, with 50 multiple-choice questions, and will last until 1:50 p.m. Bring number 2 pencils, scientific calculators, and (most importantly) 882-ES or or 882-E Scantron forms, available in the campus bookstore: any student without a Scantron will be unable to take the exam.

Devices that can communicate outside the classroom, including Blackberries or cell phones, may not be used during PSci 21 exams, even if only used as calculators with the communications functions switched off.

• There will be NO constellation identification (from maps). Those will be on the Final Exam.

• Pages 90 to 163 of the Class Notes. Take notes while reading, it really does help.
  

• Chapters 2, 8, 9, 10, and 11 of Astronomy (6th ed.), by Dinah Moche',
  

• Pages 136-138 of The Stars, by H. A. Rey (on Moon phases),
  

• What everything is made of, and what molecules, isotopes, radioactivity, and plasma are, and the characteristics of the various states of matter. (See pages 96-100 of the Class Notes.)
  

• Be able to convert between the Fahrenheit, Celsius, and Kelvin temperature scales. What is the significance of 0 Kelvin? [It is absolute zero, the total absence of heat, when molecular motion should stop completely.] (See page 100 of the Class Notes.)
  

• Know the difference between heat and temperature, and know the laws of thermodynamics (how energy moves around). (See pages 101-103 of the Class Notes.)
  

• How radio waves, visible light, X-rays, and all other forms of electromagnetic radiation are all essentially the same thing, namely light, although human eyes can see only visible light. The shorter the wavelength, the higher the frequency, and the higher the energy. Bluer light will therefore have a shorter wavelength, a higher frequency, and a higher energy per photon. (See page 104-105 of the Class Notes.)
  

• How any hot, opaque object makes a thermal spectrum (also called a blackbody spectrum), and how this spectrum acts at different temperatures. [The peak wavelength (at which the brightness is greatest) becomes bluer, as temperature increases, so hot stars are blue, whereas cooler star are red. Cooler objects, such as human bodies, make infrared light. Really hot objects, with temperatures of millions of degrees, make X-rays.] (See pages 105-107 of the Class Notes.)
  

• Kirchoff's laws of spectral lines: (1) blackbodies make continuous spectra; (2) thin gases make emission [bright line] spectra; (3) hot objects surrounded by thin gas such as stars make absorption [dark line] spectra. (See page 105 of the Class Notes).
  

• Aside from the physical state of the gas, what else do spectra tell us? Many things, including: (1) Chemical composition; (2) Temperatures; (3) Motion toward or away from the observer, by the Doppler effect. How does the Doppler effect work? [By compressing the waves made by objects moving toward you, which causes a blue shift for light (or the pitch to rise, for sound), and by stretching the waves of objects going away from you, which causes a red shift for light (or the pitch to fall, for sound).] (See 104-108 pages of the Class Notes.)
  

• Telescopes and detectors: the difference between refractors and reflectors (see page 109 of the Class Notes).
  

• How to calculate a telescope's magnification, given the focal length of the objective (or telescope) and the focal length of the eyepiece. (See page 110 of the Class Notes.)
  

• The properties of telescopes, in order of importance: (1) (Most important, since without it you can't see anything) Light-gathering power; (2) Image resolution (or in other words, how clearly you can see things, or in other words, the smallest detail you can see); (2a) Portability, for small telescopes; (3) Magnification (which is the least important, since you can change it just by changing eyepieces). (See pages 111-112 of the Class Notes.)
  

• How a telescope's collecting area (which depends on the square of the aperture) determines the faintest objects it can detect. (See page 112 of the Class Notes.)
  

• What do astronomers specifically mean by the term "seeing"? [Seeing is the amount of atmospheric turbulence. "Good seeing" means little turbulence, allowing images with resolutions of less than 1 arcsecond to be made. In "poor seeing," the air is turbulent, only allowing image resolution of 3-4 arcseconds, or more.] (See page 111-113 of the Class Notes.)
  

• Why are mountaintops often good astronomical sites? [Because they often have excellent seeing, since the Earth's atmosphere has not broken up into turbulence.] (See page 113 of the Class Notes.)
  

• Why is it desirable to put telescopes on spacecraft? [Because the seeing in space is perfect, since one is above the Earth's turbulent atmosphere; and also one can detect radiation that doesn't get through Earth's atmosphere, such as ultraviolet and higher-energy radiation, which is absorbed by the ozone layer, and infrared light, which is absorbed by water vapor.] (See pages 111 and 113 of the Class Notes.)
  

• How the wave phenomenon of diffraction limits the smallest detail any telescope can clearly resolve, and how it is possible to beat this by connecting more than one telescope, in an interferometer, which has the resolution of a telescope with an aperture as large as the distance between the telescopes (which can be thousands of km!). (See page 113 of the Class Notes.)
  

• Why digital CCDs are nearly perfect astronomical detectors (see page 111 of the Class Notes), and the properties of other detectors, including the eye and photography (see pages 114 and 119 of the Class Notes).
  

• Why one should never buy a telescope that has "600 power" written on the box. (See pages 115-116 of the Class Notes.)
  

• The advantages of binoculars as a first telescope, and how they are classified, for example: 7x50 binoculars have a magnification of 7x [or 7 power] and an aperture of 50mm. (See page 118 of the Class Notes.)
  

• How do we know how the Solar System formed? How do we know how old rocks are? (Answers: The presence of impact craters shows the importance of planetesimal accretion in the early Solar System. Radioactive dating is used to find the ages of rocks. We can also use the crater density of a surface to find its relative age [heavily cratered = older], if we have samples that show its absolute age. See pages 122-133 of the Class Notes)
  

• What four types of extrasolar planets have been found so far? How were they detected? Why were the first three types surprises? (Answers: pulsar planets, hot Jupiters, eccentric Jupiters, and classical Jupiters. The first three classes were completely unexpected, because they were unlike anything in the Solar System. We might threfore expect to find a lot more that's strange and unexpected, out there.) (See pages 123 of the Class Notes.)
  

• The four primary geological processes (impact cratering, tectonism, volcanism, and gradation), and their relative importance in shaping the surfaces of the Earth, Earth's Moon, the other terrestrial planets (Mercury, Venus, and Mars). Look them up in the Class Notes, and write them down yourself into a table.
  

• Why the Moon has phases, and at what times of night the Moon rises and sets, at different phases (shown on page 135 of the Class Notes, and on pages 136-138 of The Stars, by H. A. Rey).
  

• What happens during lunar and solar eclipses (including partial, annular, and total solar eclipses), and what causes them, and especially, eye safety for eclipse observing! (See pages 136-139 of the Class Notes).
  

• What is serendipity? [It's a happy accident, so useful in science, like for example the discovery of X-rays, or how the Allende meteorite fell in 1969, just when the lab for examining the Moon rocks was built.] (See page 152 of the Class Notes.)
  

• What's the difference between a meteoroid, a meteor, and a meteorite? (Look it up, on page 153 of the Class Notes.) What's the difference between an asteroid and a comet? (Not much: asteroids are mostly rocky and are mainly from the Inner Solar System, and comets are mostly icy and are from the Outer Solar System, but the more we learn about both, the more we find they are similar.) What are Kuiper Belt Objects? (KBOs are also called Trans-Neptunian Objects, or Ice Dwarfs, or Plutinos: they are small, icy bodies, beyond the orbit of Neptune, over 100 of which have been discovered only recently, since 1992.) What is the status of Pluto? (It occupies a unique place, much like Australia does: Pluto is the smallest planet, but it is also the largest Trans-Neptunian Object.)
  

• Compare the temperatures, densities, and compositions of the atmospheres of Venus, Earth, and Mars. (The atmosphere of Venus is hot enough to melt tin and lead, has a pressure about equal to the water at the bottom of Earth's oceans and so would crush a human to death instantly, has no free oxygen or water, is full of clouds of sulfuric acid. Venus is hotter than Mercury, even though it is farther from the Sun, because of the Greenhouse effect: What is this? [Look it up, in the text by Neil Comins.] The atmosphere of Mars is cold and thin, but is made mainly of carbon dioxide, much like the atmosphere of Venus. Earth's atmosphere is about 70% nitrogen gas, which is fairly inert, but is also extremely rich in oxygen, comprising over 20%. So much oxygen should not be here---it is so reactive, it should chemically react out of the atmosphere instantly, with other gases that are present---but it is replenished every day by life, mainly photosynthetic bacteria and plants.) (See pages 154-159 of the Class Notes.)
  

• Where do we find complex organic matter ("brown organic tarry gunk", the chemical precursor of life) in space? (It's found seemingly everywhere it can exist: comets, asteroids, meteorites, the atmospheres of Titan, Triton, and the Jovian planets, but not the surfaces of Mercury or Venus, where it's much too hot, or Earth, where life forms ate it all long ago, or Mars, where ultraviolet light from the Sun breaks it down, because the atmosphere of Mars is too thin to have an ozone layer.) See pages 160-161 of the Class Notes on "Brown organic tarry gunk" in the Outer Solar System.)
  

• How are Jovian planets different from Terrestrial planets, compositionally? [They are almost all hydrogen and helium gas, much like the Sun, although cooler.] How are the Jovian planets, or "gas giants," similar to miniature Solar Systems? (Look it up, on page 162 of the Class Notes.)
  

• How the four primary geological processes have shaped landforms on the outer planets' large satellites, including Io, Europa, Ganymede, and Callisto (Jupiter's large moons), Titan (Saturn's large moon), and Triton (Neptune's large moon). (See page 163 of the Class Notes.)