Though Beyond Earth is only the most basic introduction to the quest for life in space, one quite suitable for junior high students and up, it is wonderfully clear and comprehensive.
The author first recounts humankind's earliest creation myths, from Babylonian times up through the time of the Copernican revolution. Then he methodically outlines basic concepts of physics, chemistry and biology that he relates not only to life on Earth, but also to his point that natural laws as we know them may dictate the whereabouts and form of life in space. Also, Gallant does a good job of recounting the current theories of the universe's origin, helping to link earlier material to the dimensions of the universe.
Though past books have also accomplished these aims admirably and are still useful, this book is valuable today because it contains a detailed account of the most recent life-search methods used currently…. (p. 50)
Perhaps aware of the fact that all this talk about binary star systems and hydrocarbons can get a bit dry, Gallant has included selections of classic science fiction showing how authors of several decades have depicted other-worldly beings…. [He] keeps hands off and lets the reader enjoy the perhaps improbable scenarios, allowing the reader a moment of escape and romance that is yet not too far removed from the facts. (pp. 50-1)
John Adams, "'Beyond Earth: The Search for Extraterrestrial Life'," in Young Adult Cooperative Book Review Group of Massachusetts, Vol. 14, No. 3, February, 1978, pp. 50-1.