INTRODUCTION HEAVY METAL A group of Vietnamese officials inspect a metal container believed to be a Russian air tank that fell from space In January 2016 a sound like thunder rumbled through the skies of northern Vietnam Right after that three round metal containers fell to the ground The largest container about 39 inches 99 centimeters across and about 99 pounds 45 kilograms came to rest near a stream A smaller container landed in a neighborhood yard The smallest one hit a roof and then rolled onto the ground Officials from Vietnam’s defense department examined the containers The investigation showed that they were tanks for holding compressed air and that they’d been made in Russia One aerospace expert guessed that the tanks had come from an 4
This artists’s depiction shows several satellites orbiting Earth artificial satellite a human-made craft designed to orbit circle around Earth in space Controlled by humans on the ground more than a thousand working satellites orbit Earth They do different jobs such as studying weather transmitting telephone signals and making photographs of Earth from space Most people rarely think about satellites But occasionally parts of satellites and other spacecraft come crashing to the ground reminding us that the space around Earth is not empty Not only is it home to satellites it is also home to millions of pieces of human-made debris commonly called space junk Sometimes old satellites explode shooting pieces of debris into space
This large piece of space junk landed in Texas after falling from orbit DANGER ZONE This wasn’t the first time something had fallen to Earth from space Space junk has been a growing problem ever since space exploration began In 2013 for example about 600 pounds 272 kg of metal from a European satellite fell from the sky and landed in the South Atlantic Ocean And this kind of garbage is even more dangerous in space Millions of pieces of metal old spacecraft and satellites orbit Earth at up to 17,500 miles 28,164 kilometers per hour Working spacecraft and astronauts have a high chance of being hit by this orbiting garbage In fact in 2015 three astronauts aboard the International Space Station ISS were ready to head back to Earth in a space capsule to avoid being hit by a piece of a satellite hurtling toward them 6
The space around Earth is filled with so much junk that agencies on the ground monitor it around the clock They track all but the smallest pieces of space junk using radar telescopes and other equipment If monitors see that a large piece of junk is headed for a spacecraft or a satellite they alert the craft’s controllers who move the craft out of the way Orbiting space junk made this hole in a satellite inset Operators in the main control room for the European Space Agency ESA monitor space junk and control spacecraft below 7
