This day in 2009 marked the first time in history that two artificial satellites collided at high velocity in the Earth’s orbit.
The satellites in question were the Russian Kosmos-2251 and the American Iridium 33. The Russian satellite had a mass of around 900 kilograms and was non-functional at the time of the collision (it had stopped functioning back in 1995, but remained in orbit).
On the other hand, the American satellite was active, a part of the Iridium global satellite network, intended for telecommunication (the network has 66 active satellites in orbit, which allow people on Earth to use satellite phones).
Since the satellites were approaching each other from opposite directions, they collided at a combined velocity of 42,120 km/h. Of course, such a powerful collision released a large amount of energy, and also produced much shrapnel. There existed a fear that space debris could threaten other objects in the Earth’s orbit, especially the International Space Station.
Namely, NASA estimated that around 1,000 pieces of shrapnel larger than 10 cm and an even larger number of smaller pieces were created by the collision. The collision occurred at an altitude of 789 km, above the Taymyr Peninsula in Siberia.