Leaving Earth for another planet is going to be a challenge. Sure, there's the matter of building the rocket and launching it, but what do you do after you get into low orbit and have to make your way through the thousands of satellites that are huddled around Earth?

If the European Space Agency's (ESA) short video, "Space Debris: A Journey to Earth," is any indication, you'll end up like the space station in the Sandra Bullock movie "Gravity."

Produced for the European Conference on Space Debris, the video suggests a "Cosmos" like journey into outer space before we're yanked back to Earth to face the truth of our satellite obsession. Thousands of machines surround our planet, providing us with telecommunications, survey data and more, but many of them don't work any longer; they just spin around our planet at something like 17,500 mph, and we just hope they don't crash into something.

Except the odds are getting ever higher that that's exactly what's going to happen.

There are an estimated 750,000 pieces of space junk out there larger than 1 centimeter, according to the ESA, and more 20,000 of them are bigger than softballs. Some of them, however, are just flecks of paint or shards of previously crashed satellites. (Oh, paint shards, you might say. What can they do? Well, they can crack the window of a space shuttle, and that can go badly quickly.)

Of particular concern to the ESA are small satellites that practically anyone with access to a rocket payload can launch. These micro satellites are great for communications, but they're horrible at practically everything else, reports the Washington Post. They don't have navigation and as such, they'll just keep orbiting long after they've stopped working, making them prime targets for a collision. In fact, according to one researcher at the conference, the wall of tiny satellites that's potentially on its way more than doubles the risk for space debris collisions.

The ESA's video makes recommendations on how to handle all this space junk, and here's a big one: make sure the spacecraft can fall back to Earth. But this is a difficult recommendation to enforce, so it may be a while until many of us can get away safely from our planet to explore the great beyond.

Editor's note: This file has been updated since it was published in April 2017.

Houston, we have a space debris problem
The European Space Agency's film "Space Debris - A Journey to Earth" takes a somber look at the threats of space junk.