Voyager 1, the world’s first and only spacecraft to ever enter interstellar space, is currently surfing a big wave caused by the sun.
There is no longer any debate—Voyager 1 is in interstellar space. Launched in 1977 to explore Jupiter and Saturn, the resilient little craft is still going strong, even now that it has unequivocally entered the heliopause, the region of space where particles emitted by the sun constantly collide with the molecules of the thin gas that occupies interstellar space. Even so, Voyager 1, despite some headlines last year, has not left the Solar System.
Aboard Voyager 1 is a plasma wave detector designed by Don Gurnett of the University of Iowa, and the instrument is providing valuable insight into the craft’s immediate environment.
“It’s extremely quiet out there,” said Gurnett. “The magnetic fields are constant, the flux of cosmic rays is constant”—a sharp contrast to the turmoil of the so-called termination shock, where particles racing outward at a million miles per hour slam into the relatively stationary particles that make up the interstellar medium.”
Currently, however, as Gurnett explained this week in an annual meeting of the American Geophysical Union in San Francisco, the heliopause is reeling from a blast of particles released by a large solar storm back in February. The eruption, called a coronal mass ejection, is of a kind and magnitude that can potentially knock out communications and electrical grids on Earth.
Out in space, the blast of particles is causing a kind of massive cosmic tsunami that Gurnett likened to the vibrations produced in surrounding air by a giant ringing bell. NASA released a recording made by Voyager 1 of the phenomenon.
“This shows us how much influence the Sun can have on the surrounding area,” said Ed Stone, Caltech physicist and Voyager project scientist since 1972. “[A]nd it’s very likely to be the same with other stars.”