One of the two identical Voyager probes, as photographed by NASA.
One of the two identical Voyager probes, as photographed by NASA. NASA

More than three decades after launching from Earth, Voyager 1 is about to leave the solar system. The probe, which was originally launched along with companion spacecraft Voyager 2 in 1977, has entered a new and uncharted region of space between our solar system and the interstellar space beyond that NASA is calling a kind of “cosmic purgatory,” the Telegraph reports.

The Voyager missions were launched to study Jupiter and Saturn, but thus far they have just kept on trucking toward the far reaches of interstellar space. Each has enough fuel on board to keep going until 2020, when it is estimated Voyager 1 will be some 12.4 billion miles away from the sun.

For now, Voyager 1 is about 11 billion miles from the sun and traveling at just less than 11 miles per second, beaming back data across that distance as it goes. The cosmic purgatory is so-defined because it’s a kind of stagnation region on the cusp of the bubble that envelopes our solar system and the space beyond. Solar winds here are erratic and–for the first time–blowing back inward at Voyager. This stagnation layer was long theorized to be at the fringe of the solar system, but this is the first hard evidence of its existence out there.

Voyager 1 will likely spend months to perhaps more than a year traversing the stagnation zone before emerging into interstellar space (Voyager 2 will follow). When it crosses into interstellar space, it will be the first man-made object to do so and will remain the most well-traveled man-made object in the universe. At that point we’ll get our first data back from the galactic space in between stars, and our first real glimpse of what lays beyond the confines of our own solar system.