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 ...

Scientists have long thought that tectonic plates needed to dive beneath each other to create the chemical fingerprint we see ...

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 ...