Voyager 2 spacecraft escapes the sun’s bubble

Craft is about 11B miles from Earth

Since it left Earth 41 years ago, the Voyager 2 spacecraft has sailed across the solar system on a stream of energetic particles from the sun.

But on Nov. 5, the solar wind abruptly stopped. The current of charged particles dissipated. There was a period of turbulence, and then the probe found a strange new quality to the environment around it.

Voyager had crossed the heliopause, where the river of solar particles meets the vast ocean of interstellar space. It is now beyond the bubble of our sun’s influence, NASA announced Monday.

For the second time, a humanmade object has ventured into the void between the stars.

Its companion probe, Voyager 1, crossed that threshold in 2012. But Voyager 2 still possesses a working plasma instrument. This allows the spacecraft to sense a different kind of charged particle, called galactic cosmic rays.

After decades of looking at the galaxy “through the clouded lens of our heliosphere,” NASA physicist Georgia de Nolfo said, “we’re now able to take a step outside with Voyager and contemplate the vistas of our local galactic neighborhood.”

The spacecraft is about 11 billion miles from Earth — so far that it takes signals traveling at the speed of light 16.5 hours to reach mission control at the Jet Propulsion Laboratory in California. That’s 37 times farther than the journey from Earth to Mars.

Neither of the Voyager probes has technically left the solar system, said Ed Stone, project scientist for the mission since 1972. In about 300 years, they will reach the edge of the Oort cloud — a halo of icy bodies loosely bound by the sun’s gravity that is thought to be the source of comets. It will take another 40,000 years for the spacecraft to exit that cloud and be influenced by another star.