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 ...

The document contains drafts that refer to Galileo's presentation of a new telescope to the Doge of Venice on August 24, 1609 and his observations of Jupiter using a telescope in January 1610.

By Michael Blanding Galileo Galilei was peering through a new telescope in 1610 when he noticed something strange: several bright objects flickering around the planet Jupiter that seemed to change ...

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 July 30, 1610, the famous astronomer Galileo Galilei became the first to observe rings around the planet Saturn. Shortly after the telescope was invented in 1608, Galileo peered out into the ...

By Michael Blanding When the University of Michigan Library announced last month that one of its most prized possessions, a manuscript said to have been written by Galileo around 1610, was in fact ...

Improving on the original Dutch invention, Galileo made a device that could magnify 20 or even 30 times. In the fall of 1609 and the winter of 1610, he aimed this instrument at the night sky and ...