(Photo: ESA)

The Cupola on the International Space Station provides, as the European Space Agency puts it, the best room with a view anywhere. 

Built as an observatory, the seven-windowed module was attached to the ISS six years ago, used by astronauts for experiments, to aid in docking, and for staring out into the dark abyss. 

The windows are the largest ever put in space. Each is thick too, containing four panes of glass, because there’s a lot of space garbage out there. And even the tiniest fleck can cause a huge amount of damage, since the ISS orbits the earth at approximately 17,150 miles per hour. 

(Photo: NASA/Public Domain)

So yesterday, when Tim Peake, a British astronaut, tweeted the top image, it was both reassuring and a little frightening. ESA said that the chip in one of the Cupola’s windows was likely caused by a fleck the size of flake of paint, or possibly an even smaller piece of metal debris. 

The episode raised fresh questions about what some scientists have worried about for years: the Kessler Syndrome, the idea that we’re putting so much garbage into space that we may soon render it uninhabitable, and impossible for orbiting satellites. More space debris means more collisions between space debris, meaning even tinier and more numerous space debris, until you reach a point of no return, the theory goes. (For a visual representation of what this might look like, see the film Gravity.)

Still, we’re not quite there yet, and, for his part, Peake didn’t seem too concerned. “I am often asked if the International Space Station is hit by space debris,” Peake tweeted. “Yes–this is the chip in one of our Cupola windows, glad it is quadruple glazed!”