Think outer space is a featureless zone of nothing for thousands and thousands of vacuumed miles beyond Earth’s surface? Well, maybe it used to be, but in the mere handful of decades that humans have been playing around up there, we’ve managed to leave plenty of our toys flying around for somebody else to pick up. In fact, Earth is surrounded on all sides by a veritable mechanical atmosphere of man-made debris from missions past, even the smallest pieces of which can be hazardous to those space toys with which we still want to play. Over our heads at any given moment are dead satellites, parts of launch vehicles, and plenty of smaller bits and pieces discarded from various missions.
To give you an idea of how vast this trash blanket is, there are over 21,000 pieces of junk over 4 inches long and 500,000 pieces between 10 and 1 cm long. Those pieces under 1 cm across are thought to number in the millions. These smaller pieces may not sound like much of an issue, but the European Space Agency asserts that “even a 1 cm nut could hit with the force of a hand grenade.”
(European Space Agency)
In case you’re not taking these tinier space fragments seriously yet, the following stat should drive the point home: Objects in Low-Earth Orbit whip around at 4 miles per second – yes, PER SECOND – meaning that getting hit by a tiny paint flake from a NASA logo would be like getting hit with a 550 pound object (an adult wildebeest, for example) traveling at 60 mph.
The video below shows how big space trash can become smaller space trash, and how that small space trash can quickly get in everyone’s back yard.
Incredibly, the U.S. and Russian governments actually have a pretty good handle on the exact location of each piece of trash. Pieces down to 4 inches can be found using Earth based optical telescopes and radar devices. Before a launch, mission control can produce a map of exactly where problematic debris will be at a given time and can try to plot a course that avoids it. Working spacecraft in orbit can also alter their courses to avoid oncoming pieces as well.
While we’re able to monitor most of the mess, those punch-packing parcels under 4 inches are still an issue. For this reason, most of today’s space craft are heavily armored so an impact with a rogue screw won’t mean the end of the mission. To read about some ideas to clean up the debris, check out Space.com’s 7 Wild Ways to Destroy Orbital Debris, and in the mean time, watch out for speeding wildebeests.