Luna 1, launched January 2, 1959 from the Soviet Union, made its closest approach to the Moon on January 4. It was the first flyby of the moon by a man-made object, although it was meant to crash into the moon. It missed the moon by about 3700 miles and remains in a heliocentric orbit between Earth and Mars.
It still managed to send back data on Earth’s outer Van Allen radiation belt and determined the Moon to have no discernable magnetic field. Its flyby of the moon came one year to the day Sputnik 1 entered Earth’s atmosphere and disintegrated.