However, since the asteroid was determined to be so small and therefore harmless, no further impact alerts were issued by NASA.
"This was a much smaller object than we are tasked to detect and warn about", said Lindley Johnson, planetary defense officer at NASA Headquarters, in a statement from the agency. "However, this real-world event allows us to exercise our capabilities and gives some confidence our impact prediction models are adequate to respond to the potential impact of a larger object".
The manager of the NEOC Paul Chodas said: 'The discovery of Asteroid 2018 LA is on the the third time that an asteroid has been discovered to be on an impact trajectory with the Earth. The rock hit Earth's atmosphere at 1644 UTC on Saturday, and a webcam in Botswana caught a glimpse of the meteor as it exploded several miles above the Earth's surface.
The discovery observations of Asteroid 2018 LA. If one of them comes hurtling to Earth, we could have only days, if that, between when it is spotted and when it hits-and that result would be more devastation than dazzling.
Only twice before has a small asteroid been detected hours before colliding with Earth.
An asteroid turned into a blazing fireball as it disintegrated over southern Africa last weekend, just hours after it was first spotted. The asteroid hit Earth's atmosphere over the southern African nation of Botswana at 12:44 p.m. EDT (1644 GMT) while hurtling down at a whopping 38,000 miles per hour (61,155 km/h).
This is the incredible moment a high-speed asteroid the size of a vehicle explodes over the South African wilderness just seconds before impact. About eight hours after these images were taken, the asteroid entered Earth's atmosphere (about 12:44 p.m. EDT, 6:44 p.m. local Botswana time), and disintegrated in the upper atmosphere near Botswana, Africa.
The first event of this kind was the impact of asteroid 2008 TC3, which lit up the predawn sky above Northern Sudan on October 7, 2008. Churning through the data at top speed, astronomers at the Minor Planet Center and NASA's Center for Near-Earth Object Studies (CNEOS) confirmed that the space rock was on a collision course for our planet. The Catalina Sky Survey has been responsible for discovering all three of these small asteroids on impact trajectories, and all on the watch of the same observer, Richard Kowalski. The second was 2014 AA, discovered only a few hours before it impacted over the Atlantic Ocean on January 1, 2014.
He said: "The advantage I had was I saw it in colour and it was not like on the cameras".