I've seen enough sci-fi shows to know that frightening things can lurk outside windows in space. In fiction, those things are usually aliens that want to eat you, but in real life there are different dangers out there in the dark expanse. European Space Agency astronaut Tim Peake tweeted a photo on Thursday showing a disconcerting sight through a window on the International Space Station.
Peake's close-up shows a chip caused by an impact from space debris. The damage is located in the cupola, a place that's used as an observatory with multiple windows giving a good view of Earth. The chip, about a quarter of an inch (7 millimeters), looks a lot like what happens when a small rock strikes your car windshield. The ESA says it could have been caused by impact from an object as small as a paint flake.
The ESA notes chips like this one "pose no threat." The window is extremely thick and in no danger of breaking. Space debris is a growing problem as evidenced by this video of the build-up of orbital junk over the past six decades. The ESA says a piece of debris larger than about 4 inches (10 centimeters) "could shatter a satellite or spacecraft into pieces." So far, the ISS is doing a good job of avoiding that problem.