’Last night, after seven years and five billion kilometers, Stardust came home at last.
The comet mission sample container was ejected from the main spacecraft right on time, re-entered Earth’s atmosphere, and fell to the Utah desert pretty much as planned (though windy conditions blew it around a bit, making it harder to find in the desert). It was picked up and flown to the U.S. Air Force Utah Test and Training Range, and eventually will find its way to a NASA lab where scientists can study the captured comet particles, and investigate the make-up of these orbiting snowballs.
I went out last night to try to see it, but I missed it. Maybe if I had planned as well as my friend Bill Keel, an astronomer at the university of Alabama, I might have seen it. He and his students caught it while it was still 160,000 km from the Earth:
(Click the image for a larger version). Once the sample capsule hit the Earth’s atmosphere at 46,000+ km/hour, it became quite a spectacle:
Hard to believe I missed it, isn’t it? I was trying to figure out why last night as I got into bed at 3:00 a.m. At first, I figured it was just too low in my sky, but then I found out about someone in San Jose who saw it. That’s south of me, farther from the re-entry point. If they saw it, I should have. It might have happened behind some mountains north of me (maybe, plus smoke coming out of my neighbor’s chimney would have helped obscure it had it been visible). But that still seemed unlikely to me.
But then I started thinking about it differently, and now I wonder. I was thinking of this as being like a satellite, moving slowly across the sky. But that’s the wrong model for this! It was moving, 13 kilometers/second, more like a meteor than a satellite. I realized suddenly the whole thing was over in ten seconds or so, and it was only really bright for less than that (I’m waiting for more reports to see if anyone timed the events). A neighbor’s friend pulled up in her car right around the time of re-entry, and I went over to ask her to turn her lights off because I was hoping to take pictures of the sky. Did it happen at that moment? I’m not sure. Arrrrg!
I should have had a watch with me. I should have paid attention to time better. I should have plotted its path using sky-mapping software so I’d have been looking at just the right spot. I should have should have should have. Given that Mrs. Bad Astronomer and the Littlest Astronomer got up to see this as well, I’d better plan things more carefully next time! I doubt I’ll be able to get Mrs. BA out for the next early morning astronomical event as it is.
In the end, I missed it because I blew it. Next time I’ll know better. I hope.
The important thing is that it’s home, it’s safe, and it’s on its way to the people best suited to study it. In fact, there’s a way you (yes, you) can help study the comet’s particles, but that’s a story for my next blog entry.’