Stephen Hawking Nasa

Professor Stephen Hawking was a longtime friend to NASA, and a brilliant cosmologist and an inspiration to generations around the world, said the US space agency in honor of the acclaimed British physicist, who died a day ago.

A US spacecraft sailed past the tiny planet Pluto in the distant reaches of the solar system on Tuesday, capping a journey of 3 billion miles (4.88 billion km) that began nine and a half years ago.

For decades, US astrophysicists seeking to make contact with extraterrestrials have basically just been listening for signals from space.

Professor Stephen Hawking was a longtime friend to NASA, and a brilliant cosmologist and an inspiration to generations around the world, said the US space agency in honor of the acclaimed British physicist, who died a day ago.

A US spacecraft sailed past the tiny planet Pluto in the distant reaches of the solar system on Tuesday, capping a journey of 3 billion miles (4.88 billion km) that began nine and a half years ago.

For decades, US astrophysicists seeking to make contact with extraterrestrials have basically just been listening for signals from space.