Dr. Plait created his popular web site: http://www.badastronomy.com/index.html, to debunk bad astronomy in popular culture. This website proved popular, which led to this first book by Plait, that carries on from the website and in a detailed and clear fashion criticises and disproves popular myths and misconceptions relating to astronomy, and promotes science as a means of explaining the skies.

The work describes 24 common astronomical fallacies, including the beliefs that the Coriolis effect determines the direction that water drains in a bathtub, and that planetary alignments can cause disaster on Earth. The author sharply and convincingly dismisses astrology, creationism, and UFO sightings, and explains the principles behind basic general concepts (the Big Bang, why the sky is blue, etc.).