Treasure hunt

 Michael - Thursday

Most treasure hunts in Botswana are after the mysterious source of the Namibian alluvial diamonds (Death of the Mantis), undiscovered animals and plants (Dying to Live), and new diamond-bearing kimberlites (A Carrion Death). But in June 2018, an intrepid team set out to find something far more rare than diamonds. The search area couldn’t have been more challenging. It was in the north of the Central Kalahari Game Reserve, an area larger than the Netherlands. Situated in the heart of Botswana, it's a semiarid wilderness. If you get lost there, you’d better have plenty of water and a satellite phone. Take a look at the satellite image of the Motopi Pan area HERE.

Fortunately, these explorers had a good idea of where to look. In fact, the source of their target was photographed by a CCTV camera a few nights before, and they knew roughly where they expected it to be. Take a look at the clip:

They were searching for fragments of asteroid of an asteroid which only a few weeks before was spotted on a collision course with Earth. If it had been big, I might not be writing this blog today, but it was only about two cu metres (50 cu feet) and 5,000 kg (10,000 lbs), and it was expected to largely burn up before it reached the ground. Still, it was travelling at about 60,000 km per hour as it entered the atmosphere. 

It was the pieces that reached the ground that the team was interested in.

The next day, the team started their treasure hunt. It included scientists from the Botswana Geoscience Institute, and an international team of meteorite experts. Meteorites are not very rare, but they become weathered and contaminated. The excitement was for a piece that would be brand new. However, they knew that almost all of the material had been destroyed.

This lion looks as though he could have spotted a geologist...

Gemsbok with lion roaring

Guards from the Botswana national park accompanied them. Despite its arid nature, the CKGR is rich in all sorts of wildlife, not all of it friendly. To make matters worse, what they were looking for was pretty similar to the animal droppings that scattered the Kalahari sand. Mohutsiwa Gabadirwe, a geologist and curator at the Botswana Geoscience Institute, called it, “a totally unusual experience for all of us.” 

It seemed that this treasure hunt was going to end the same way as most of them do. After three weeks of searching, they'd found nothing. Long hours and long walks in all the most likely locations had left them with empty hands and sore feet.

Near Mtopi campsite

Then, on the last day of the expedition, the 23^rd of June, they finally had success. They were near Motopi Pan and so the fragment is known as the Motopi meteorite. There it was, lying waiting to be picked up. 

2018 LA in situ 

A moment to remember

This month, there was a sequel to the story. Playing detective, astrophysicists have managed to trace 2018 LA back to its original home. It seems that, just as it died with a bang, it was born with a bang when another small asteroid crashed into Vesta, which is a serious asteroid. The resulting explosion produced a crater named Rubria and sent masses of material out into space, including the chuck that started on a twenty-two million year journey to rendezvous with Earth.

Rubria crater on Vesta from NASA's DAWN spacecraft

As Rra Gabadirwe put it, “It is such an amazing thing to be in possession of such a rare specimen with so much history attached to it.”