Ancient space probes sent out on a long-distance research mission during the 1970s are continuing to send back valuable data 30 years after they first launched. The Voyager 1 and Voyager 2 spacecraft have each now entered a vast region of space on the very edge of the solar system, a point where the solar wind blowing outward meets the interstellar wind blowing in.
You can think of it a bit like a balloon or bubble. The probes each crossed the threshold – excitingly named the Termination Shock (there’s a superbly poor taste abortion joke in there somewhere) – at different points a mere 10 billion or so miles from each other. However, the twist is that Voyager 2 reached it considerably closer than its twin, taking scientists by surprise.
They were, of course, extremely excited. The probe encountered a “complex, rippled, quasi-perpendicular supercritical magnetohydrodynamic shock of moderate strength undergoing reformation on a scale of a few hours,” they said. Oh yeah? Well, they should have seen what I found in the sink this morning.
The upshot of all this is that Solar System is not quite the neat sphere we thought it was. It’s more like an oblong, or possibly a blob squashing up against something. No doubt some yahoo backed a star into it at some point. They probably didn’t even leave a note.
The Voyager probes are by no means finished with their epic journey either. They are continuing to march onward ever further into deep space. Researchers expect the Voyager 1 to reach interstellar space in the five to seven years. Who knows what kind of fascinating shape that will turn out to be?
(via Ars Technica)