Planetary Science: A Space Odyssey

摘要

Millennia before anyone realized Earth was only one member of a family of planets orbiting the sun, astute observers noticed a handful of stars that were different. They moved relative to the rest of the stars, which all traveled across the sky as though they were fixed to an enormous rotating bowl. These unusual stars appeared to wander. They became known by the Greek word for wanderers—planets, in English. Planetary science entered its first great epoch of discovery in the 16th century as the scientific revolution itself was developing momentum. Planetary motion was one of the first test-beds for the new physics that was emerging. The second great epoch of discovery, which continues today, began a half-century ago. With the advent of the Space Age in the late 1950s and the continuous development of powerful new tools of observation, planetary scientists have been generating a steady flow of startling revelations, including the recent discovery of planets around other stars, as well as some conditions for life in extraterrestrial settings.