Information the probes transmit has allowed scientists to construct a better picture of what it's like on the edge of the solar system that abuts the space beyond, the BBC reported.
Computer modeling based on the Voyager data indicates the edge of the solar system could be similar to an "agitated Jacuzzi," said Eugene Parker from the University of Chicago.
Magnetic field lines carried in the "wind" of material break and reconnect, creating distinct bubbles tens of millions of kilometers wide, researchers said. The assessment could affect the understanding of cosmic rays.
"It's more like a membrane that is permeable to the galactic cosmic rays, so we expect the galactic cosmic rays to enter and slowly wander through this sea of magnetic bubbles until they can access field lines that connect back to the sun and quickly escape," Parker said.
Researchers say they're surprised at the amount of activity found on the outer reaches of the solar system.
"The findings are significant as we will have to change our view on how the sun interacts with particles, fields and gases from other stars, and this has consequences that reach down to Earth," said Arik Posner, Voyager program scientist at NASA.
The Voyager probes first surveyed Jupiter, Saturn, Uranus and Neptune, completing those missions in 1989. Now their primary task is to define the sun's limits.