An asteroid of this size only passes this close every decade or so, making this a fairly rare occurrence.
Despite a near miss in space terms there is no chance the asteroid will hit earth during its fly by, which will take place around midnight. According to orbit calculations made by NASA's Jet Propulsion Laboratory, the May 15 close approach is the closest of this particular asteroid in almost 300 years.
The asteroid was first identified in 2010, though it quickly vanished into space, Patrick Taylor, a scientist at the Universities Space Research Association at the Lunar and Planetary Institute in Houston, told Business Insider.
2010 WC9 completes one complete orbit every 1.12 years and approaches the sun as close as.78 astronomical units and as far away as 1.38 AU. It passed within nine million miles of Earth and then scientists lost track of it as it headed back to the outer solar system.
For those hoping to catch a glimpse of the space rock, WC9 may prove elusive without a telescope.
"We knew that it would likely come close in May of 2018". However, many amateur astronomers are going to get their telescopes out and should spot the asteroid at the right time. But, persons wishing to see the asteroid can tune in to Slooh, the astronomy broadcasting service beginning at 4 pm Alaska time.