Washington, June 28 (ANI): NASA's Voyager 1 is close to becoming the first human-made object to reach interstellar space.
Research using Voyager 1 data provides new detail on the last region the spacecraft will cross before it leaves the heliosphere, or the bubble around our Sun, and enters interstellar space.
Three papers describe how Voyager 1's entry into a region called the magnetic highway resulted in simultaneous observations of the highest rate so far of charged particles from outside heliosphere and the disappearance of charged particles from inside the heliosphere.
Scientists have seen two of the three signs of interstellar arrival they expected to see: charged particles disappearing as they zoom out along the solar magnetic field, and cosmic rays from far outside zooming in.
Scientists have not yet seen the third sign, an abrupt change in the direction of the magnetic field, which would indicate the presence of the interstellar magnetic field.
"This strange, last region before interstellar space is coming into focus, thanks to Voyager 1, humankind's most distant scout," Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena, said.
"If you looked at the cosmic ray and energetic particle data in isolation, you might think Voyager had reached interstellar space, but the team feels Voyager 1 has not yet gotten there because we are still within the domain of the Sun's magnetic field," he said.
Scientists do not know exactly how far Voyager 1 has to go to reach interstellar space.
They estimate it could take several more months, or even years, to get there.
The heliosphere extends at least 8 billion miles (13 billion kilometers) beyond all the planets in our solar system.
Voyager 1 and its twin spacecraft, Voyager 2, were launched in 1977.
They toured Jupiter, Saturn, Uranus and Neptune before embarking on their interstellar mission in 1990.
They now aim to leave the heliosphere. Measuring the size of the heliosphere is part of the Voyagers' mission.
The findings are published in the journal Science. (ANI)