New horizons in astronomy.

Besides the study of astronomy itself, other topics included cover the geological and biological developments on earth and basic physics of matter, heat, and light. Optical and radio telescopes are discussed, as well as photographic and photoelectric means of detection. The immediate solar system is described by topics on the properties and atmospheres of the inner and outer planets, the sun's energy, sunspots, and the solar spectrum. Stars both on and off the main sequence are discussed in terms of distances, intrinsic properties, lifetimes and evolution. The Milky Way is compared to other galaxies in size, star population and structure, and the different galaxy shapes are pictured. Topics of most recent interest are covered by results of the lunar explorations, new concepts of Mars, and problems of space travel. Problems of modern astronomy include pulsars, neutron stars, and quasars.