Voyager leaves solar system 36 years after launch - first man-made object to leave the solar system -
Measurements recorded by the probe suggest that it has left the Sun's sphere of influence and entered interstellar space, the vast cold and dark region between stars.
The probe, which was launched in 1977 to study the outer planets in our solar system, has now drifted almost 12 billion miles (19 billion km) from Earth.
It actually left the hot bubble of plasma from the Sun more than a year ago, but it has taken until now for scientists to compile enough evidence to prove it is no longer under the Sun's influence.
Ed Stone, the mission's chief scientists, said: "It's a milestone and the beginning of a new journey."
The team now hopes to use the spacecraft to study exotic particles in a region of space that has never before been explored, and beam its findings back to Earth.
Should it be intercepted by any intelligent alien civilisation, they will find a gold-plated disc containing a series of multicultural greetings, songs and photographs.
Voyager-1 was launched along with its twin, Voyager-2, 36 years ago to explore the solar system's gas giants.
Last year scientists noticed that the number of charged particles interacting with the craft's sensors suddenly dropped, suggesting it had broken through into interstellar space.
There was also a corresponding rise in galactic cosmic rays hitting the craft from the other side, but there was no noticeable change in the magnetism around the craft, suggesting it was still being influenced by the Sun.
But recently a chance solar eruption caused the space around the craft to echo like a bell, proving that the boundary had already been crossed.
Don Gurnett, of the University of Iowa, who published the data in the Science journal, said: "It took us 10 seconds to realise we were in interstellar space."
Other scientists were more sceptical, however.
Jonathan McDowell, an astrophysicist from Harvard University, said: "I'm actually not going to believe it for another year or two."
Read more -
Measurements recorded by the probe suggest that it has left the Sun's sphere of influence and entered interstellar space, the vast cold and dark region between stars.
The probe, which was launched in 1977 to study the outer planets in our solar system, has now drifted almost 12 billion miles (19 billion km) from Earth.
It actually left the hot bubble of plasma from the Sun more than a year ago, but it has taken until now for scientists to compile enough evidence to prove it is no longer under the Sun's influence.
Ed Stone, the mission's chief scientists, said: "It's a milestone and the beginning of a new journey."
The team now hopes to use the spacecraft to study exotic particles in a region of space that has never before been explored, and beam its findings back to Earth.
Should it be intercepted by any intelligent alien civilisation, they will find a gold-plated disc containing a series of multicultural greetings, songs and photographs.
Voyager-1 was launched along with its twin, Voyager-2, 36 years ago to explore the solar system's gas giants.
Last year scientists noticed that the number of charged particles interacting with the craft's sensors suddenly dropped, suggesting it had broken through into interstellar space.
There was also a corresponding rise in galactic cosmic rays hitting the craft from the other side, but there was no noticeable change in the magnetism around the craft, suggesting it was still being influenced by the Sun.
But recently a chance solar eruption caused the space around the craft to echo like a bell, proving that the boundary had already been crossed.
Don Gurnett, of the University of Iowa, who published the data in the Science journal, said: "It took us 10 seconds to realise we were in interstellar space."
Other scientists were more sceptical, however.
Jonathan McDowell, an astrophysicist from Harvard University, said: "I'm actually not going to believe it for another year or two."
Read more -
