I was looking back for the best, most impressive astronomy images of the year 2012—ready to post a winner when this dropped in my NASA feed. The image is stunning on its own, but the description just made my head spin. Combined with its sheer beauty, it made it the winner. Here is why:
The blue star in the center of the image is Zeta Ophiuchi, a titanic object "six times hotter, eight times wider, 20 times more massive, and about 80,000 times as bright" than our Sun. Located 370 light-years away from us, Zeta Ophiuchi is travelling across the Universe on its own, zooming through at 24 kilometers per second. That's an incredible 54,000mph. In the image, the star is going from the right side to the left.
For an object of that size, this is quite remarkable on its own—but there is more. The reason why this image taken by the Spitzer Space Telescope is so awesome is not the star itself, but what surrounds it.
Look at the pink and green threads of dust to the left, ahead of it. They are twisted and curved, as if they were running away from the star. The fact is that these columns of stellar dust are running away from it—they weren't like this a few years ago.
They are curved because of the bow shock from Zeta Ophiuchi. As it travels, the massive star emits such powerful stellar winds that it blows away anything on its path. The star's hot gas particles travel ahead of the star—half light-year ahead. That's "almost 800 times the distance from the sun to Pluto". According to NASA, "the speed of the winds added to the star's supersonic motion result in the spectacular collision seen here."
The particles travel much faster than the star, adding to their own speed the speed of Zeta Ophiuchi. And as the particles collide with the calm dust column, they move its particles, deforming it violently.
And that is what makes my head spin: to think that this exists, that this magnificent scene happened 370 years ago and that, by now, that towering dust is probably shredded to pieces. I consider it a tiny preview of what is going to happen to the Pillars of Creation once the supernova shock gets there.
So is this the best astronomy image of the year? I think so. You can post your favorite in the comments. [NASA]