Lonely Planets: The Natural Philosophy of Alien Life

In Lonely Planets, astronomer David Grinspoon is buoyantly optimistic about the possibility that we are not alone in the universe. Grinspoon, who serves as principal scientist in the Department of Space Studies at the Southwest Research Institute, lays out a detailed but not boring case for life on other planets, dropping authoritative quotes and goofy footnotes in equal measure. The Grinspoon family hung out with Carl Sagan and other astronomical royalty, giving young David an early appreciation for SETI and the heady astrobiological theorizing of the 1970s. In the 21st century, scientists are still split on the question of extraterrestrial life. Grinspoon believes that a "natural philosophy" approach is the key to furthering our knowledge in this field, since there is precious little evidence with which to apply the scientific method. Instead of looking for the familiar and testable, he writes, we should expect the unexpected.

Expecting to find DNA elsewhere is like expecting a Star Trek universe with humanoid aliens who speak English and insist that we join them for dinner at eight.

Lonely Planets is a substantial book, covering the origins of life on Earth as well as the changes in religious and social thought that have affected astronomers' search for other planets and their theoretical inhabitants. Grinspoon's style is exuberant, even a little cocky, and the result is delightful readability. Lonely Planets lets readers share the dismay of finding out there are probably no Martians and the thrill of wondering if there might be Europans. "I think our galaxy is full of species," writes Grinspoon. "The wise ones are out there waiting for us to join them." --Therese Littleton