In February, about 500 miles above Siberia, a U.S. communications satellite smashed into a defunct Russian orbiter at 25,000 miles per hour, annihilating them both. It was the first wreck of its kind—two intact spacecraft accidentally plowing into each other at hypervelocity—in the half-century that humans have been launching objects into space.
Initially the crash left behind some 1,500 pieces of wreckage bigger than four inches in diameter, along with hundreds of thousands of smaller fragments, estimates Nicholas Johnson, chief scientist of the Orbital Debris Program Office at NASA’s Johnson Space Center in Houston. The debris clouds, initially distributed along the orbital paths of the satellites, are spreading to enshroud the entire planet, joining the roughly 19,000 large chunks of orbiting space junk (as seen in this image) already tracked by the Department of Defense.
Even if we stop launching objects into space, the amount of trash will continue to grow. “Things will keep running into each other at a faster rate than debris will fall out of orbit,” Johnson says. Another major collision is certain to happen eventually, he adds. In March, a 5-inch fragment from a spent rocket engine whizzed closely past the International Space Station. Scientists and policymakers are exploring ways to prevent future accidents by removing large, defunct objects from orbit.