Although the looping tour through the Jovian system was planned to end two years later, Galileo’s mission was extended twice so scientists could get closer pictures of Europa, with its iced-over ...

Galileo was the first to discover the moons of Jupiter. Michael Benson / Kinetikon Pictures / Corbis (Jupiter) / Scala / Art Resource, NY (Galileo) Inside a glass case was a plain-looking tube ...