At more than 5,000 kilometers (more than 3,000 miles) across, Ganymede rivals Mercury in size ... created by an asteroid impact about 4 billion years ago, but we were unsure how big this impact ...

The enormous visitor to our solar system may have been about 8 times the mass of Jupiter, and come nearly as close to the sun ...

Four billion years ago, Ganymede literally got knocked sideways ... solar system’s largest moon Ganymede is a moon larger ...

Mercury will become part of HP Software, pushing that group's revenue past $2 billion annually ... felt like two companies sat down five years ago and said, 'We'll go build all this ...