IS THERE LIFE IN OUTER SPACE?

WRITING HIS NATURAL HISTORY IN THE FIRST CENTURY A.D., Pliny the Elder reported that when water rises into the atmosphere to form rain clouds, it sucks up with it shoals of fish and sometimes quantities of stones. Fish and stones hover above us in the sky. Elsewhere, Pliny offered an item about a woman who gave birth to an elephant. He was, occasionally, a supermarket-tabloid sort of Roman.

A Pliny pattern persists. The scientific side of the observer's mind demands objective evidence, as the great naturalist usually did; but the brain's mythopoeic, magic-thinking side is lured to marvels--to alchemy, to spells,...