July, 1965: The intrepid probe named Mariner 4 makes its famous flyby of the planet Mars.
It was a great moment in the history of NASA, especially since people had been working so long at trying to get a probe to Mars. Six previous attempts had failed, and people were beginning to joke about a mysterious force that was keeping humans from observing Mars too closely. Mariner put an end to the mystery, cruising by at six thousand miles altitude and sending back the first images of the surface of Mars.
After sweeping past Mars, its mission was over, so mariner 4 headed back into deep space since it didn't have enough fuel to remain near Mars. Mission control just left it in orbit in the region between Mars and Earth. Back home, the public didn't hear anything more about it. The mission had been a success, and that was that.
Now here's the surprise. Two years later, in September of 1967, something completely unexpected happened. The probe was just drifting along in empty space, still sending signals to Earth. Suddenly, out of the darkness, an enormous shower of meteors started pummeling it. They battered poor Mariner so hard they tore off insulation and turned the craft around in space. For three quarters of an hour Mariner was kicked up one side and down the other by a meteor shower more intense than any recorded on Earth.
Until this point, astronomers through the area between Earth and Mars was just empty space. However, this occurance changed their minds.