Voyager 1’s Journey Continues to Stump Scientists

Jeffrey Kluger, writing for Time:

Reanalyzing data from last year, scientists determined that the spacecraft is now in a region it calls the heliosphere depletion region. The previously unidentified zone is characterized by a dramatic spike in cosmic rays—the exotic stuff that streams in from the stars—and an extreme decline in particles from the sun. So far, about what was expected—even if the measurements are better than ever.

Much more significantly, the magnetic field lines at last began to change significantly, with particles following the magnetic lines flowing out from the sun all but disappearing, meaning that solar magnetism was at last losing its influence and being overtaken by the interstellar magnetism. But the magnetic lines still did not change their direction, as they would have to if they were truly locking into the grid of deeper space.

An artist's rendering of the positions of the Voyager 1 (top) and Voyager 2 (bottom) relative to what we think is the edge of the solar system.

As new data like these are analyzed, scientists revise their models and expectations of what the edge of the solar system will look like, exatctly. But they also acknowledge, according to David McComas, head of NASA’s IBEX mission, which is also probing the outer reaches of our solar system, that we won’t know for sure until we’re there:

Every new bit of data coming from the venerable spacecraft is teaching us more about this uncharted territory. All of this information is new, and we are learning more every day.

But that doesn’t mean sceintists like McComas don’t have any hypotheses. Find out what (we think) we’ll see when Voyager 1 finally enters the interstellar medium by reading McComas’s commentary here on NOVA Next.