Humans are messy, and not just here on Earth. Now, you can see all the junk we’ve launched into space for yourself with a data-driven animation created for the United Kingdom's Royal Institution by Stuart Grey, an astronomer at University College London. It all begins in 1957 when the Soviet Union launches Sputnik, a 58.5-centimeter-wide ball emitting radio pulses. A piece of the rocket that took it into orbit was the very first piece of space junk. The United States launched its own satellite, Explorer 1, the next year. Almost every mission into space has created new debris, either from the launch vehicles, objects falling off satellites, or unintended collisions. By the time the USSR launched the first human into space, cosmonaut Yuri Gagarin, there were 200 objects floating around up there. By 1980 we had landed a man on the moon and left nearly 5000 objects in orbit. And because of deep space exploration, not all of them are tiny. Entire rocket engines are lurking around up there. The number of objects remained stable at about 9000 until suddenly, in 2007, a Chinese ballistic missile test exploded and added 2000 chunks of metal to the mix. In 2009, a couple of big satellites collided and added yet another 2000. You get the picture. We now stand at about 20,000 known pieces of space debris bigger than an apple—that is, an apple capable of ripping through a steel wall at 17,000 miles per hour—and there's bound to be more. Space is becoming a very cluttered place, making it all the more dangerous to send humans up there to our orbit and beyond.

(Video credit: Stuart Grey)