with a homemade telescope, noticed three points of light near Jupiter. Initially believing they were distant stars, Galileo’s repeated observations over several nights and realized they were ...

Galileo's telescope opened the skies to observation; Hawking's equations made the invisible visible, from black holes to the Big Bang. It's staggering to think about what these two men accomplished.

Inset: Galileo's sketch of the triple body he saw through his early telescope. Credit ... is known about Saturn's rings today comes from observations made by the Voyager probes and Cassini's ...

In his 2006 book, Galileo’s Instruments of Credit: Telescopes, Images ... starting with Galileo’s observations of the four largest moons of Jupiter in January, 1610. It is a discovery that ...