Exoplanets

January 2, 2017
Readers tour several bizarre worlds in this slim read, as Summers and Trefil, professors of physics at George Mason University, show how “defining a ‘planet’ has been made significantly more difficult” in the exoplanet age. Astronomical investigations outside our celestial backyard are ripe with paradigm shifts because scientists suffered “the curse of the single example”: our solar system and carbon-based life. Detailed photos and illustrations aid “visits” to unusual worlds, including 55 Cancri e, where volcanoes spew liquid diamond; Kepler 186f, with its vast lagoons and black flora that absorb “what energy they can from the faint sun”; and a rogue planet wandering dark space, where any life “must see in the infrared” and be warmed by the planet’s core. The authors temper runaway imaginations with scientific uncertainties about each location, and they reexamine the Drake equation—used in the search for extraterrestrial life—in light of our current understanding of exosystem frequency and dynamics. Summers and Trefil write confidently and straightforwardly for lay readers, who will long ponder what planets circle other suns and the peculiar possibilities of life beyond our blue marble. Illus. Agent: Leslie Gardner, Artellus Ltd. (U.K.).