Complex sentence: The collision occurred at 16:56 UTC on February 10,2009, at above the Taymyr Peninsula in Siberia, when Iridium 33 and Kosmos-2251 collided at a speed of 42,120 km/h (26,170 mi/h).
Split into simpler sentences: The collision occurred at 16:56 UTC on February 10,2009, at above the Taymyr Peninsula in Siberia, when Iridium 33 and Kosmos-2251 collided. The satellites collided at a speed of 42,120 km/h (26,170 mi/h).