Space is a dangerous place. It’s not just the lack of oxygen or gravity; the biggest threat, at least in low Earth orbit, is micrometeorites and other debris that circle our planet at very high speeds.
At several kilometers (miles) per second, or faster, even small objects pack a punch, so much so that they can pierce through the International Space Station.
There is so much debris and micrometeorites floating around in space that impact is inevitable. In fact, one just hit the ISS though, thankfully, it just pierced through the solar panels. ISS Commander Chris Hadfield provided the Twitter evidence.
It did leave a bullet hole though as a reminder of what might happen if one were to hit the hull.
Luckily, the ISS’ hull is made up of multiple layers designed to contain and slow down debris so that it doesn’t pierce through. The ISS also navigates around areas where large quantities of debris are known to exist.