Nasa’s Voyager 2 has become only the second human-made object to reach the space between stars.
Nasa said on Monday that Voyager 2 exited the region of the sun’s influence last month.
The spacecraft is now beyond the outer boundary of the heliosphere, some 11 billion miles from Earth.
It is trailing Voyager 1, which reached interstellar space in 2012.
Interstellar space is the vast mostly emptiness between star systems.
According to Nasa, the Voyagers are still technically in our solar system.
Scientists maintain the solar system stretches to the outer edge of the so-called Oort Cloud.
It will take thousands of years for the spacecraft to get that far.
Despite the great distance, flight controllers are still in contact with Voyager 2.
The Voyagers launched from Cape Canaveral, Florida, in 1977.