Introduction to the physical universe. Topics include: constellations, gravity, radiation, the Sun, structure and evolution of stars, neutron stars, and black holes, the Milky Way galaxy, normal galaxies, active galaxies, quasars, cosmology, and the search for extraterrestrial life. There is one required text for this course. This course fulfills the natural and mathematical sciences requirements. Credit is not given for both A105 and A110.