An asteroid about the size of a school bus is expected to "safely zoom past earth" on Thursday, according to NASA's Jet Propulsion Laboratory in Pasadena.
The "2020 SW" asteroid, which scientists believe based on its brightness to be about 15-30 feet in size, will travel about 13,000 miles above Earth's surface, JPL reported.
"Although it's not on an impact trajectory with Earth, if it were, the space rock would almost certainly break up high in the atmosphere, becoming a bright meteor known as a fireball,'' an official with JPL said Tuesday.
2020 SW was discovered Friday by Catalina Sky Survey, which is based in Arizona and funded by NASA.
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Scientists have ruled out any chance of impact, and it is believed that there are 100 million asteroids that are similar in size, but are harder to discover unless they are close to Earth, JPL reported.
"There are a large number of tiny asteroids like this one, and several of them approach our planet as close as this several times every year," said Paul Chodas, director of the Center for Near-Earth Object Studies at JPL.
"In fact, asteroids of this size impact our atmosphere at an average rate of about once every year or two."
"The detection capabilities of NASA's asteroid surveys are continually improving, and we should now expect to find asteroids of this size a couple days before they come near our planet."
NASA has been tasked with finding 90% of near-Earth asteroids that are 460 feet or larger in size, according to JPL.
"These asteroids pose a much greater threat if they were to impact, and they can be detected much farther away from Earth, because they're simply much brighter than the small ones,'"JPL reported.