Voyager may already left solar system for interstellar space
Nasa's long-lived Voyager probe probably crossed into interstellar space last year, becoming the first man-made object to leave the solar system, research suggests.
Nasa's long-lived Voyager probe probably crossed into interstellar space last year, becoming the first man-made object to leave the solar system, research suggests.
Scientists had been waiting for Voyager to detect a magnetic field that flows in a different direction to the solar system's magnetic field, but those behind the new research say that scenario is not accurate.
"We think that the magnetic field within the solar system and in the interstellar are aligned enough that you can actually pass through without seeing a huge change in direction," University of Maryland physicist Marc Swisdak said.
That would mean that Voyager reached interstellar space last summer, when it detected a sudden drop in the number of particles coming from the sun and a corresponding rise in the number of galactic cosmic rays coming from interstellar space.
Not everyone is convinced, however.
Voyager lead scientist Edward Stone, now retired from the US space agency's jet propulsion laboratory said Swisdak's research was interesting but different computer models were portraying different scenarios to explain the Voyager data.
"We know where Voyager is in terms of distance and we know what it is observing. The challenge is relating that to these complex models of the interaction between the interstellar medium and the heliosphere," Stone said, referring to the bubble of space that falls under the sun's influence.
Stone and other scientists believe Voyager is in a previously unknown region, dubbed a "magnetic highway", that exists between the heliosphere and interstellar space.
Voyager 1 and a sister probe, Voyager 2, were launched in 1977 to study the outer planets. Voyager 1 is now about 120 times farther away from the sun than earth. Voyager 2 is heading out of the solar system in a different direction.
