Our planet has a space junk problem.
In 1957, Russian scientists launched the tiny satellite Sputnik, whose beeping signal would mark the start of the Space Race, provoking Americans to launch Explorer I soon after. The metal sphere was just the first of many satellites, rocket parts and spacecraft debris that make up the more than 500,000 bits of miscellany larger than a marble that now orbit Earth.
A new visualization by astronomer Stuart Grey, of University College London, makes the scope of the issue abundantly clear. “Almost every mission into space has created new debris, either from the launch vehicles, objects falling off satellites, or unintended collisions,” writes John Bohannon for Science.
The visualization jettisons along through the history of space junk since Sputnik’s launch. And though the early years seem fast, wait till you see the year 2007, when a Chinese ballistic missile tests exploded, adding 2,000 more pieces to the space. A collision between two satellites in 2009 added about 2,000 more.
The objects in the visualization aren't to scale, but are all larger than an apple, “that is, an apple capable of ripping through a steel wall at 17,000 miles per hour,” Bohannon writes. The speed at which these objects orbit means that each of the roughly 20,000 items in this size class can do a bit of damage. The largest piece out there is about the size of a bus, according to Grey’s visualization.
The concern isn’t that the space junk will fall to Earth and cause damage (though it can happen) but rather that they could wreck crafts that venture outside the planet’s atmosphere. The International Space Station has to dodge orbiting debris several times a year.
Possible solutions for the problem include a Swiss craft that will gobble up non-functional satellites like a PacMan and fitting the International Space Station with a laser to zap incoming debris.
First, however, experts need to better understand the scope of the junk cloud surrounding the planet. That’s why Grey’s visualization is useful. He draws on data from Space-Track.org, a project developed by the U.S. Air Force to keep track of artificial satellites and space probes. And their ability to track will continue to improve. Early in 2015, the Air Force started building a more sophisticated radar system to see smaller pieces. That system should be online in 2019.
Earth’s orbit is looking mighty crowded and dangerous.