1.  Read units 11, 12, 21, 22, 29 in the textbook, list questions you have about the reading, and ask them during class time.

1a.  Go to the following website for a quick, easy, good summary of electromagnetic radiation:
http://imagers.gsfc.nasa.gov/ems/waves3.html

1b.  Another short, sweet summary (with illustrations) of different types of spectrum (emission, absorption, black-body) is at the following website:  http://csep10.phys.utk.edu/astr162/lect/light/absorption.html

1c.  For supplemental reading, go to unit 2 instructor notes.

1d.  The following website answers almost every question about the use of light, including the history of how astronomers learned to use it to identify the chemical makeup of the Sun.  Also see links to other references as well as applets for exercises to enhance your understanding.
http://outreach.atnf.csiro.au/education/senior/astrophysics/spectro_history.html

1e.  For a look at the emission line spectra for some chemical elements (including the all-important hydrogen and helium), go to the following page:
http://astro.u-strasbg.fr/~koppen/discharge/

1f.  Different types of objects and/or processes in astronomy result in different kinds of electromagnetic spectra.  Go to the following link for a vivid, short example of this - we'll discuss it briefly in class:
http://heasarc.gsfc.nasa.gov/docs/objects/heapow/archive/active_galaxies/m81_xmm.html

1g.  A firestorm of controversy erupted after President Bush proposed redirecting part of the NASA budget to support a new Moon-Mars initiative.  The proposed redirection includes letting the Hubble Space Telescope degrade until it no longer functions (2-3 years).  For a non-partisan discussion of the challenges, costs, and scientific tradeoffs of such a long-range mission, read a comprehensive article by Steven Weinberg, one of the world's top physicists (also active and influential in astronomy):  http://www.slick-net.com/rnr/wrg_stf.phtml This saga will serve as an excellent tutorial (some day) about big-bucks science and politics.  For much more typical caustic comments on the Moon-Mars initiative, see the following:  http://blog.zmag.org/ee_links/federal_budget

2.  Respond with written answers to the unit 2 discussion questions.   I'll take questions about these during class time.   Assess your responses by comparing with my unit 2 DQ responses (available sometime Friday) on this web-site, as instructed on my responses page.  Turn in your self-assessed discussion questions the first day of unit 3.