Voyager scientists say the spacecraft, launched in 1977, has encountered a region in space where the intensity of charged particles from beyond the solar system has markedly increased, leading to the historic conclusion humanity's first emissary to interstellar space is about to depart the solar system, NASA's Jet Propulsion Laboratory in Pasadena, Calif., reported Friday.
"The laws of physics say that someday Voyager will become the first human-made object to enter interstellar space but we still do not know exactly when that someday will be," Voyager project scientist Ed Stone said.
"The latest data indicate that we are clearly in a new region where things are changing more quickly. It is very exciting. We are approaching the solar system's frontier."
Launched in 1977, Voyager 1 and its sibling Voyager 2 are in good order. Voyager 1 is 11.1 billion miles from the sun while Voyager 2 is at 9.1 billion miles distance.
"When the Voyagers launched in 1977, the space age was all of 20 years old," Stone said. "Many of us on the team dreamed of reaching interstellar space, but we really had no way of knowing how long a journey it would be -- or if these two vehicles that we invested so much time and energy in would operate long enough to reach it."