It was sort of a romantic notion, I guess: the idea that, as the solar system moves through the interstellar medium, the interaction between the outward flowing solar wind and the medium creates shockwave. Makes us seem like a missile traveling through space. At least, it makes for a pretty picture, as these examples around other stars shows:
Heliosheath (Courtesy NASA)
Heliosheath 2 (Courtesy NASA)
Well, no such luck. It turns out our velocity vector isn’t in quite the right direction and its magnitude with respect to the interstellar medium isn’t great enough to produce a bow shock. Sucks, doesn’t it? I mean, we knew our Sun was pretty average as far as stars come, but give it a bow shock and, I don’t know, it sort of adds character. Now, we’re just back to being boring. Alien astronomers probably don’t even give our Sun a second look. And this was what was responsible for bursting our bubble:
IBEX (Courtesy NASA)
That’s IBEX – the Interstellar Boundary Explorer – and its goal seems to be to make us feel even more inferior than we already felt in this unremarkable arm of the Milky Way. We can’t really blame it, though – it’s only doing its job. I blame the scientists who for decades based their research on the existence of the bow shock, convincing us casual observers that our Sun really did produce such a fascinating phenomenon. It was such a glamorous theory that they lulled themselves into believing it before the evidence was in. Well, IBEX has just served them up a piece of humble pie. Serves them right.
Actually, this is a huge gift to the astronomers who were wrong, because now they can get paid redoing all their research based on the new facts. Go figure.