Coined 2014 DX110, the asteroid will be part of a rare class of objects that comes nearer than the moon, and will shave by at around 2100 GMT, the space agency said.
"As happens about 20 times a year with current detection capabilities, a known asteroid will safely pass Earth Wednesday closer than the distance from Earth to the moon," NASA said on its website.
Its closest approach to Earth will be at about 3,50,000 kilometers, a bit closer than the average lunar distance of 3,85,000 kilometers.
The asteroid is believed to be about 100 feet across, or 30 meters.
NASA discovered it as part of its asteroid tracking efforts, called the Near-Earth Object Observations Program.