The first known NEO (Near Earth Object) passed by the Earth on October 30th 1937. The asteroid called Hermes missed the Earth by 485,000 miles which by today’s near misses is quite a distance.
It worried astronomers because until Hermes, astronomers were skeptical about asteroids hitting the Earth. It was only recovered again 66 years later in 2003. Hermes crosses the Earth’s orbit twice every 777 days but it is usually at a great distance and normally very faint.