As the video above shows, since the Soviet Union first launched Sputnik in 1957, an excess of debris has piled up around Earth. The visualization above—created by Dr Stuart Grey, University College London, for the Royal Institution of Great Britain (RIGB)—makes it crystal-clear: Space has a littering problem.
While the video may appear to show random specks circling the globe, it doesn’t. The animation is based on tracking data from Space-Track.org, and each of those “specks” is in fact a piece of orbiting space trash. The RIGB has also posted a detailed interactive version with explanatory captions as part of their advent calendar, which is full of space-related stuff worth seeing.
As for the mess we made after decades in space, it wasn’t always such a dire situation. It started slowly, with just a few things left behind as the Soviet and American space efforts escalated in the early 1960s. Since then, it’s been a steady stream of missions—with an accompanying swirling mass of left-behind debris. It's estimated that there are currently about of 20,000 pieces of space debris in orbit, ranging from the size of an apple to a school bus.
Space exploration has made many invaluable breakthroughs possible—from landing on the moon to reliable cell phone service. Going forward though, one hopes we’ll do a better job of housekeeping amongst the stars.