Hard to believe this has never happened: Two satellites—one American, one Russian, insert Cold War pun here—have crashed in space near the International Space Station, spewing a cloud of debris. The crash of the commercial Iridium communications satellite and the defunct Russian Cosmos 2251 satellite occurred over northern Siberia and is said to be no threat to the space station, though the resulting 600 pieces of debris may put other satellites at risk. "They collided at an altitude of 790 kilometers (491 miles) over northern Siberia Tuesday about noon Washington time," said NASA's chief scientist for orbital debris. "The US space surveillance network detected a large number of debris from both objects." Asked which satellite was at fault, he said, "They ran into each other. Nothing has the right of way up there. We don't have an air traffic controller in space. There is no universal way of knowing what's coming in your direction." Most of the debris is expected to burn up in Earth's atmosphere.