The US Air Force tracks about 20,000 pieces of orbiting space junk and that includes dead satellites. The most obvious sign that space is polluted with junk is the frequency with which pieces of debris have falling out of the sky. In the last two years, a defunct NASA satellite and a failed Russian space probe have fallen to the Earth. While the odds that anyone here on Earth will get hit are low, the chances that all this orbiting litter will interfere with working satellites or the International Space Station, which dodges pieces of debris with increasing frequency, are getting higher, according to a recent report by the National Research Council. The non-profit group, which dispenses advice on scientific matters, concluded that the problem of extra-terrestrial clutter had reached a point where, if nothing was done, a cascade of collisions would eventually make low-Earth orbit unusable.
Researchers are stepping in with a variety of creative solutions, including nets that would round up wayward items and drag them into the Earth’s atmosphere, where they would harmlessly burn up.