An asteroid turned into a blazing fireball as it disintegrated over southern Africa last weekend, just hours after it was first spotted. The space rock was very faint, with observations suggesting it was just 6 feet (2 meters) across - small enough to burn up completely during its fiery plunge through the atmosphere, NASA officials said.
The final moments of the asteroid's existence appear to have been caught by a webcam in South Africa and posted online.
"This was a much smaller object than we are tasked to detect and warn about", said Lindley Johnson, Planetary Defense Officer at NASA Headquarters. Researchers there quickly determined its trajectory put the rock on a probable collision course with Earth.
The boulder-size asteroid was discovered on Saturday morning, according to NASA's Center for Near Earth Object Studies. Astronomers have spotted, plotted, and forecasted asteroid flybys months, years, and even decades ahead of time but sometimes space rocks can be sneaky, especially when they're small.
After scientists at the Catalina Sky Survey spotted the asteroid, they relayed their observations to scientists at the Minor Planet Center in Cambridge, Massachusetts. The asteroid hit Earth 8 hours after these images were taken, burning up in Earth's upper atmosphere over Botswana, Africa.
'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'. According to CNEOS records, the asteroid's distance from Earth's centre, at closest approach, was calculated to be 5,874 km, which is well inside the planet's radius of 6,371 km. That trajectory plot was the first hint that 2018 LA could hit Earth.
A small chunk of an asteroid or comet is also known as a meteoroid. Most are located in the asteroid belt between Mars and Jupiter, but occasionally some can get jostled out of their orbit, posing a threat to Earth.
Astronomers can easily track massive space rocks big enough to cause the extinction of humanity.
Scientists discovered the asteroid, called 2018 LA, early Saturday. Although they started off at the top of the atmosphere travelling at tens of thousands of kilometres per hour, by the time they reached the ground, they would only be moving at around 300-500 km/h - at the most, a quarter of the velocity of a bullet. Expert Geoff Notkin tells us how! The 2014 asteroid was discovered just a few hours before entering over the Atlantic, with little time for tracking.
There have been only two other times when asteroids were detected so soon before impact. The same asteroid hunter, Richard Kowalski, made all three discoveries.
In 2008, 13-foot asteroid 2008 TC3 disintegrated over the skies of northern Sudan approximately 19 hours after discovery. The previous times were in 2008 and 2014.