Look to the stars. Although Astronomy has been around for more than 5,500 years, astronomers say that we've learned more than 90% of what we know about the universe in just the last 50-and much of that in the last decade! The Complete Idiot's Guide(r) to Astronomy, Fourth Edition, continues to be the most comprehensive introduction to the topic, covering all the latest advances and discoveries, including: • The demotion of Pluto and promotion of Ceres as planetary objects • Breakthrough evidence of recent water flow on Mars • New developments in asteroid-tracking programs • New information on the nature and shape of our universe • Mind-bending theories concerning multiple universes • Information on the latest telescopes As a bonus, this book includes a fascinating CDROM with more than 200 of the most spectacular images from NASA, star maps, and other tools for backyard astronomers.