On 30 August, NASA’s Voyager 2 spacecraft — which has been sailing through space since 1977 — crossed the ‘termination shock’, the boundary between the bubble in space dominated by the solar wind coming from the Sun and the transition region beyond that lies between Earth and interstellar space.
Voyager 2’s twin, Voyager 1, crossed this same boundary in December 2004. But Voyager 2 did it while almost 1 billion miles closer to the Sun, suggesting that something — such as an interstellar magnetic field — is compressing the bubble of the solar wind on that side.
Because Voyager 2 crossed the heliosheath boundary, called the solar wind termination shock, about 10 billion miles away from Voyager 1 and almost a billion miles closer to the sun, it confirmed that our solar system is ” squashed” or ” dented”- that the bubble carved into interstellar space by the solar wind is not perfectly round. Where Voyager 2 made its crossing, the bubble is pushed in closer to the sun by the local interstellar magnetic field.
“Termination shock” is a poetic piece of jargon. Astronomers are actually calling it the “final frontier.”