Life on our planet is certainly miraculous - not in a theological sense, but in the extraordinary sequence of events and processes that seem to have been crucial in creating an Earth suitable for life.
Ah, "not in a theological sense." It's an enormously incredible confluence of specific circumstances that allows life, justifying the term "miraculous." But we can't talk about God, can we?
The book reviewed is celebrated science writer John Gribbin's The Reason Why: The Miracle of Life on Earth. So Gribbin uses "miracle" too, and in his title. Nice touch.
The upshot of the book is that the existence of the moon is the most important factor of many in allowing life to develop and thrive here. Why that's so important is aptly summarized in the review, as is the implication that other potentially life-bearing planets are all the more unlikely as a result.
But, apparently, still not as unlikely as God.