The layer is being called a "highway" because it allows particles into and out of the solar system, Scientific American explained. While the outer region is connected to interstellar space, it also remains inside the Sun's magnetic field.
“Although Voyager 1 still is inside the sun’s environment, we now can taste what it’s like on the outside because the particles are zipping in and out on this magnetic highway,” Voyager team member Edward Stone said in a NASA press release.
“We believe this is the last leg of our journey to interstellar space," he continued. "Our best guess is it’s likely just a few months to a couple years away. The new region isn’t what we expected, but we’ve come to expect the unexpected from Voyager.”
Voyager 1 and its sister probe Voyager 2 were launched into space in 1977, and are inching closer and closer to becoming the first man-made objects to exit the solar system, Mashable reported.
The pair run on radioactive batteries, and are expected to stop operating in 2025. They will most likely make it out of the heliosphere — the solar system's outermost cushion — by then, Reuters reported.