It turns out that Chicken Little wasn’t entirely wrong. Technically it’s not the sky that’s falling, but a lot of stuff in the sky is. Some of it is quite a bit bigger than the acorn that landed on Chicken Little, too.
In case you missed it — and thank goodness, it missed you! — a German satellite weighing 2½ tons fell out of orbit in late October. It seems to have crashed into the Indian Ocean.
The month before that (September, 2011), an even larger piece of hardware tumbled from the sky. That one, a dead NASA satellite, was the size of a bus and weighed 6 tons. According to the news agency Reuters, it was torn apart during re-entry, but more than 20 pieces didn’t burn up during the fall — the largest was estimated to have weighed 330 pounds.
Fortunately, those chunks of UARS (Upper Atmosphere Research Satellite) didn’t hit a populated area. They splashed into the Pacific Ocean, probably causing a lot of fish to exclaim, “What the hell was that!?”
Until its sudden descent, it was one of over 20,000 hunks of space debris that are large enough to be monitored from earth. When you include screws and bolts and chips of paint and other objects floating around up there that can’t be seen on a tracking screen, the pieces of debris are estimated by NASA to number in the tens of millions.
The International Space Station is equipped with shields that protect it from the inevitable impacts with small objects. According to The Week magazine, however, the crew has had to maneuver the station 5 times since 2008 to avoid large, potentially damaging objects. In June, the crew was prepared to abandon ship when a piece of junk was headed toward the space station; it missed impact by less than a quarter mile.
There are occasional collisions in space; in 2009 a Russian communications satellite that was no longer in service smacked into an American satellite that was. That caused the abrupt end of some phone conversations on earth: “Dude, I was thinking we could hang out, have a coupla brews, and… hello? Hello?” The collision also created, as The Week reported, “another 2,000 chunks of orbiting scrap.”
That stuff will probably be joining us one of these days, through the process NASA calls “natural orbital decay”. The space agency estimates that at least one piece of trash hits our planet every day. The good news is that the odds of it hitting you (yes, you personally) are, well, astronomical — at least a billion to one.
In fact, since the space age began in the 1950s, only one person on earth has been hit by falling space junk. In 1977, Lottie Williams of Tulsa, Oklahoma, was in a local park around 3:30 a.m. when she saw a ball of fire in the sky.
A little while later she felt something tap her on the shoulder. The thing bounced off and made a metallic clank when it hit the ground. It was about the size of her hand, Ms. Williams told ABC News, but very light; she wasn’t injured. Eventually it was determined to have been part of a Delta II rocket body.
Even if the chances of being hit by space junk are slim, I’m going to take precautions. For starters, I intend to stay out of public parks at 3:30 in the morning.