Remnant of Bright Fireball That Exploded Over Africa Recovered in Desert
Most residents of Botswana had no idea that a bright white fireball would explode in the sky on June 2. It lit up the sky as it zoomed through the upper atmosphere, illuminating the region in a strange white glow before it exploded in a flash of light. Since then, researchers have been scouring the area for traces of the asteroid, and on Monday, they announced their success: After days of searching in the desert, they’d found a piece of the once-great fireball.
The fragment of asteroid 2018 LA was discovered in Botswana’s Central Kalahari Game Reserve, which, at 20,400 square miles, is the second-largest reserve of its kind in the world. To find it in that enormous swath of the Kalahari desert, researchers from the SETI Institute, the University of Botswana’s Okavango Research Institute, NASA, and the Astronomical Society of Southern Africa combed through surveillance videos and other footage to calculate the meteor’s exact position and altitude.
They got a headstart by using data collected by the University of Arizona’s Catalina Sky Survey, which actually spotted the asteroid eight hours before it raced toward Earth.
“The biggest uncertainty we faced was to determine where exactly the meteorites fell,” says SETI senior research scientist Peter Jenniskens, Ph.D., a subject expert of the SETI Institute in California, in a statement released Friday. The team discovered that the asteroid broke up into many fragments, which were scattered by the wind. Fortunately, they were able to narrow down the fragments’ whereabouts to a relatively small area of 77 square miles.
From there, the hunt became very low-tech and, at times, quite dangerous. Geoscientists from various Botswana research institutions, guided by Jenniskens, could do nothing but walk through the grass, shrubs, and sand looking for unusual stones while avoiding elephants, snakes, and lions. After five days, Lesedi Seitshiro, a student at Botswana International University of Science and Technology, spotted the small rock in the sand.
Tiny as it is, the meteorite is significant because it’s rare that anyone ever finds pieces of an asteroid first spotted in space. This is only the second time in recorded history that this has happened. In 2009, another team led by Jenniskens discovered pieces of a truck-sized asteroid that had blown up over an 18-mile stretch of the Nubian Desert in 2008. LA 2018, in comparison, was only about six feet across. As such, the Catalina Sky Survey team that spotted it deemed it non-dangerous and didn’t alert anyone, which is why it was such a surprise when the fireball lit up the Botswana sky.
It’s possible there are still pieces of LA 2018 in the reserve — the 2009 search had yielded 280 pieces — but for now, the recovered remnant of the asteroid is now the legal property of the Botswana government. It’s likely scientists will do further analysis on it, which might reveal clues about its origins and formation. The light reflectance analysis conducted on the asteroid discovered in 2009 revealed new details about F-class asteroids, which shed light on the formation of early celestial bodies at the beginning of the solar system. Over the next few months, we’ll likely find out what secrets LA 2018 has to share.