13 September 1959
The USSR Luna 2 probe impacts into another world.
This Soviet probe was the first man-made object to ever land on the Moon.
The 390 kilogram heavy probe reaches the Moon after only 36 hours of flight and landed about 800km from the center of the visible disk.
In order to confirm impact the spacecraft release a vapor cloud soon after impact that would release with a diameter of 650 kilometer that could be seen by observatories on Earth.
At the time the US thought it was well ahead in terms of guidance systems. The crash landing of the Luna 2 proved that was not the case.
The landing site of the Luna was close to the later Apollo 15 landing, as can be seen in the map below: