Voyager 1 achieved the milestone in 2012
The Voyager 2 has become only the second spacecraft to escape the heliosphere, a bubble-shaped region dominated by solar winds at the edge of the solar system.
The spacecraft launched more than 40 years ago has now entered the Interstellar Medium (ISM) a transition zone between the heliosphere and interstellar space, according to scientists at the University of Iowa.
Its twin spacecraft, Voyager 1, which was launched almost simultaneously in 1977 achieved this milestone in 2012.
The study, which was published in the journal Nature Astronomy confirmed this crossing on November 5, 2018, after the spacecraft travelled over 11 billion miles into the ISM by noting a definitive jump in plasma density detected by a plasma wave instrument on the spacecraft.
Two energetic particle detectors onboard the Voyager 2 have confirmed a huge decline in heliospheric particles and at the same time a great increase in the level of high energy cosmic rays which come from interstellar space.
These changes have confirmed the fact that the spacecraft has entered a new space zone. The Voyager 1 had also experienced such a jump in the change of particles.
Voyager 2’s crossing also reconfirmed that there is a definite boundary of the heliosphere and did not wilt away into interstellar space.
While both the Voyagers were on a different missions and pushed through different trajectories, they crossed into the ISM at similar distances. It pointed to the fact that Heliosphere is symmetric with a windsock like structure that extended to outer perimeter of the solar system.
Both these spacecrafts continue to operate and communicate data to NASA's deep space network 42 years after they were launched. Voyager 1 is the farthest a man-made object has ever travelled from the earth.
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