Proxima Centauri lies in the constellation of Centaurus (The Centaur), just over four light-years from Earth. Although it looks bright through the eye of Hubble, Proxima Centauri is not visible to the naked eye.
ESA/Hubble & NASA
When the Galileo spacecraft swooped by Jupiter's frozen moon Europa in Nov. 1997, views of its blistered surface strengthened suspicions that a briny ocean harboring life could lie beneath an icy crust.
An image of Europa released by the Jet Propulsion Laboratory in Pasadena, Calif., in 1996 by the Galileo spacecraft. NASA says a new probe dedicated to studying the Jovian moon, is going into the development phase.