Padua, Italy—During the January nights in 1610 when Galileo discovered Jupiter’s four largest moons from a balcony in this city, he remarked how the planet with its circling satellites resembled the sun and its retinue of planets. In January 2010, as celebrants from 16 countries gathered here to consider “Galileo’s Medicean Moons: Their Impact on 400 Years of Discovery,” the controversial bodies were still sparking comparisons throughout the solar system and beyond to exoplanets scattered across the Milky Way.
One of the great Italian astronomer’s own telescopes stood on public display in the palazzo where the symposium took place. The homemade appearance of the instrument—a wooden tube covered with brown paper and fitted with two small lenses—cut an impossible contrast to the remote sensing devices and future spacecraft designs that dominated the scientific presentations. Nevertheless, at every coffee break during the three-day meeting, one or more participants would gravitate to the telescope. Hyped on the genuine espresso and cappuccino being served, they stared as though they might never tire of looking at it.
