Los Angeles: NASA's Voyager 1 has reached a strange new region at the outer reaches of the solar system, a new research has said, suggesting that it has entered interstellar space.
First launched in 1977, the unmanned spacecraft has become the first human-made object to enter interstellar space, scientists say.
Further, scientists were earlier thinking if it has already left our solar system, but new research pin-points that it has not yet broken through the heliosphere, or the bubble around our Sun, and into interstellar space.
Chief scientist Ed Stone of the NASA Jet Propulsion Laboratory was quoted as saying by a news agency, "It could actually be anytime or it could be several more years”.
Stone first described this unexpected zone at a meeting of the American Geophysical Union last year. Three papers published online on Thursday in the journal Science confirmed just how strange this new layer is.
Soon after Voyager 1 crossed into this region last August, low-energy charged particles that had been plentiful suddenly zipped outside while high-energy cosmic rays from interstellar space streamed inward. Readings by one of Voyager 1's instruments showed an abrupt increase in the magnetic field strength, but there was no change in the direction of the magnetic field lines — a sign that Voyager 1 has not yet exited the solar system.
Voyager 1 and its twin, Voyager 2, were launched in 1977 to visit the giant gas planets, beaming back dazzling postcards of Jupiter, Saturn and their moons. Voyager 2 went on to tour Uranus and Neptune. After planet-hopping, they were sent on a trajectory toward interstellar space.
Voyager 1 is about 11 ½ billion miles from the sun. Voyager 2 is about 9½ billion miles from the sun. The nuclear-powered spacecraft has enough fuel to operate its instruments until around 2020.
In the meantime, scientists are looking for any clues of a departure. Given the time it takes to process the data, mission scientist Leonard Burlaga said there will be a lag between when Voyager 1 finally sails into interstellar space and when the team can confirm the act. Then there's always the possibility of surprises beyond the solar system.
"Crossing may not be an instantaneous thing," Burlaga said. "It may be complicated."
(With Agency inputs)
Source: Zee Media Bureau