Indeed. This might come as a surprise but a stray 5-inch chunk of an old rocket engine in orbit was recently threatening to damage the International Space Station. So much that the crew had moved into an escape vehicle in case the impact occurred. Thankfully, the chunk passed a safe distance from the station. Now you might wonder how a 5-inch piece of metal could harm the ISS. That’s because you probably don’t know that it was traveling at a few thousand miles an hour; space junk, and everything else in a near-earth orbit moves at such speeds. If it would’ve hit, it’d been catastrophic.
All through the Cold War, the US and the erstwhile Soviet Union were involved in what we call the Space Race: domination of the limitless beyond. It all started with the Soviets sending Sputnik into orbit, and then it was a snowball in no time. Hundreds of artificial satellites were launched during that time for purposes still secret and classified, and all of it remained up there. You see, satellites have no real engine, just small thrusters to help them maintain orbit, so they can’t be shot back to the Earth, and though there is technology to shoot down satellites, it is expensive. So once a satellite is past its age, it is simply discarded in orbit, or at most moved to what is called a graveyard orbit, a few hundred kilometres above the geosynchronous orbit.
However, it is not these defunct satellites themselves that pose a threat, but small pieces of debris which now dot outer space. Below orbits of 2,000 kms, the average impact speed is 36,000 kmph. At these speeds, even a 1 mm metal chip can do as much damage as a rifle bullet, and a pea-size ball is equivalent to a 400 pound safe travelling at 100 kmph. And a metal sphere the size of the junk that threatened the ISS is as lethal as 40 sticks of dynamite. Infact NASA has to frequently replace windows on the space shuttle that have been damaged by objects as small as a flake of paint.
There are currently about 6000 defunct satellites in orbit, and another 10,000 to 11,000 pieces of junk that can be tracked by other satellites. An estimated 15,000 to 20,000 pieces of debris lie scatted in orbit, too small to be tracked. The ISS, however, is not completely defenceless, and can lift orbit to avoid larger objects (though it is apparent that it did not lift its orbit this time, which means it was defenceless in this case). What worries me is that now we’re so tired of polluting the Earth, we’ve started doing the same to outer space. And then Christians say God created humans. Had God created humans, He’d not have given us the power to pollute places we can’t even see.