Our planet occupies a unique spot in the solar system. It is just the right distance from the Sun—within the so-called Goldilocks Zone—to be not too hot or too cold for liquid water to be stable on its surface, which, together with a protective shielding atmosphere, allowed the four-billion-year journey from a single-celled organism to an upright humanoid species. Most of primordial life, if seen today, would be classified as “alien,” as it bears little resemblance to anything that currently exists. We can learn much about the possibilities of extraterrestrial life by studying the conveyer belt of life forms from our planet's history and by exploring organisms still present in harsh environments on Earth that mimic those on other worlds. Goldilocks and the Water Bears is an accessible introduction to the most fascinating of all the astro-sciences—the quest to learn whether we are alone in the universe. Preston’s accessible writing style, enthusiasm, and optimism succeed at informing as well as tickling readers’ imaginations. - Publishers WeeklyThis fascinating selection will help readers contemplate life on Earth and beyond, as Preston thoroughly explains scientific terms and concepts. A background in science is not necessary to enjoy this title. - Library Journal.