More giants in focus

摘要

The Sun's planetary configuration seems ideally suited to the emergence of advanced life. Small, rocky planets lie in the pleasantly warm region close to the Sun. The giant, gas-rich planets orbit far enough away to avoid disturbing the rocky planets, while their gravitational perturbations help scatter incoming comets that represent a collision hazard. Is the Solar System typical or is this arrangement unusual, perhaps even unique? Writing in The Astrophysical Journal, Gould et al. present an analysis of extrasolar planetary discoveries that brings us a step closer to answering this question.