Launched in 1977, Voyager 1 is now poised to become the first craft to enter interstellar space.
The Voyager 1 probe has entered a region of space with a markedly higher flow of charged particles from beyond our solar system, researchers said. Mission scientists suspect this increased flow indicates that the spacecraft — currently 11.1 billion miles (17.8 billion kilometers) from its home planet — may be poised to cross the boundary into interstellar space.
"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," said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena, in a statement.
"The latest data indicate that we are clearly in a new region where things are changing more quickly," Stone added. "It is very exciting. We are approaching the solar system's frontier." [Photos From NASA's Voyager 1 and 2 Probes]