Right now, more than half a million pieces of man-made space junk orbit Earth, and if we don't' put a stop to the ever-growing clutter, it could become too dangerous for manned travel to space.
Our beautiful planet wasn't always like this. The overwhelming amount of space junk didn't start until after humans cracked the code on spaceflight and began sending satellites into orbit in the late '50s.
Stuart Grey, a lecturer at the University College London and a member of the Space Geodesy and Navigation Laboratory, tells the story of how it all began in this 1-minute visualization below:
Space junk accumulates because we don't clean up after ourselves. Instead of returning defunct satellites, we usually leave them out in space. But out there, they run the risk of colliding with meteors or other human-made debris, which is traveling at blazing speeds of more than 17,000 miles per hour.
A single collision will completely obliterate a satellite and turn it into hundreds of smaller pieces.
As you can imagine, this only exacerbates the problem because, after these collisions, the junk doesn't simply go flying off into space. Instead, Earth's gravity traps it in nearby orbits, which is rapidly cluttering up our path to space.
And if that path gets too crowded, it might be too dangerous to send anything into space, ever again, because the chances of a collision would be too great. It would be like sending a soldier through a mine field.
"The only way to [solve this problem] is to bring back the larger objects," NASA scientist Donald Kessler, who lead NASA's Orbital Debris Program Office for nearly 20 years, told Huffington Post in 2013.
But if we're going to do anything about this problem, then we better do it fast, Kessler said earlier this year.
"We're at what we call a 'critical density' - where there are enough large objects in space that they will collide with one another and create small debris faster than it can be removed," Kessler told Marketplace in September.
You can check out an interactive version of Grey's animation here.