The International Space Station has been hit by fast-moving debris — but it didn't cause too much damage. Space junk hurtling towards the station smashed into one of its robotic arms, leaving a hole. NASA and the Canadian Space Agency first noticed the damage on Canadarm2 on May 12, according to a recent statement.

How is the ISS protected from space debris?

The ISS has shields called Whipple bumpers. They are multi-layered with spaces between the layers. The intent is that impact with a layer will both slow and hopefully break apart the projectile, so that by the time it gets to the bottom layer it is no longer harmful.

How much debris hits the ISS?

A piece of space debris has struck the International Space Station. NASA found a hole in one of the station's robotic arms, though it's still working. Scientists monitor 23,000 pieces of space junk that could harm the station, but some debris is too small to track.