A survey of modern topics in astronomy with an emphasis on developing conceptual models for the interactions between light and matter underpinning energetic phenomena in the universe. Topics include telescopes and detectors, solar system exploration, planetary climates, nuclear fusion and chemical enrichment, stars and stellar evolution, interstellar material, pulsars, quasars, gamma ray bursts, the Big Bang and the possibility of life beyond Earth. Cross Listings: ASTR 155, PHYSICS 155, PHY-SCI 155.