Mark Wolverton

Recent scientific inquiry suggests that the possibility of intelligent extraterrestrial life is remote, writes Mark Wolverton in the following viewpoint. While simple life forms may be relatively common on other planets, the emergence of complex life depends on several factors, including a planet’s distance from its sun, climate, geological forces, and the effects of moons and other objects in the solar system. The odds that all such factors will converge in a way that allows the development of complex organisms are extremely poor, Wolverton explains. So far, Earth appears to be the only planet where all the conditions necessary to sustain complex life are present. Wolverton is a freelance science writer.

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1. According to scientists Peter Ward and Donald Brownlee, cited by the author, what...