From a home observatory in a London house on July 26, 1609, an epic journey began both for exploration, and for the lives of two pioneers: one famous, one not so much. The first known drawing of the ...

Along with countering the geocentric system, Galileo demonstrated that our Moon was not a perfect sphere, as this had also been a long-standing belief. He was the first to deduce the Moon had craters, ...

On this date, Jan. 7, 1610, astronomer Galileo Galilei, with a homemade telescope, noticed three points of light near Jupiter. Initially believing they were distant stars, Galileo’s repeated ...

On Jan. 7, 1610, Galileo discovered four moons revolving around Jupiter — a discovery that would change his life forever. These four moons are Jupiter’s largest satellites — lo, Europa, Ganymede and ...

Most of us know four moons of Jupiter, called the Galilean moons because they were first discovered by Galileo in 1610. Named for figures closely associated with Jupiter from Greek mythology, Io, ...

Turn a telescope to the eastern sky in the hours following midnight on Nov. 5 to see two colossal shadows darken the cloud tops of the gas giant Jupiter as the Galilean moons Io and Europa pass ...