“We’ve entered a totally new region of space,” says Ed Stone, Voyager project scientist and the former director of JPL.
Our entire solar system—planets and all—sits inside a gargantuan bubble of gas about four times wider than the orbit of Neptune.
The sun is responsible.
It blows the bubble by means of the solar wind. Astronomers call the bubble itself “the heliosphere” and its outer membrane “the heliosheath.”
The heliosheath is 3 to 4 billion miles in thickness, and Voyager 1 will be inside it for another 10 years or so. Story at PhysOrg