In the vastness of the universe, there must be other planets with life forms on them, a belief held by many in the scientific community and beyond. Planet Hunters by Dutch astronomer Lucas Ellerbroek introduces readers to the men and women who are on the hunt for viable exoplanets, those in the "Goldilocks zone," where the conditions are right for some form of life to exist, even on a microscopic scale. Ellerbroek examines how the first astronomers gazed at the stars--with the naked eye and then with early telescopes--and shares their thoughts and discoveries. As he does, he provides great examples to help readers understand the immense distances in space and the difficulties inherent in studying the "wobbles" of stars and planets so many millions of miles away.
Ellerbroek explains that the hunt for other livable planets was once an acceptable practice before it fell out of favor among scientists. It has since found favor as an exciting field again, now that thousands of potential life spots have been discovered. With the advent of better technology, new methods of measuring planets have emerged. Spectroscopy, for instance, breaks down light emitted from a star into a barcode of varying wavelengths based on chemical composition. Meticulous and well-researched, but not dull, Planet Hunters is infused with the enthusiasm of the many people who have devoted their lives to searching for a potential neighbor in the enormity of space. --Lee E. Cart, freelance writer and book reviewer