Botswana: Recovery of Botswana's rare meteorite can help reveal the secrets of outer space

A meteorite was found in a remote area of ​​Botswana. The event is one of a kind because the meteor was identified before entering the atmosphere, and its fall and recovery have been documented. It's only the second time that happens. The Moina Spooner Conversation from Africa spoke to Fulvio Franchi and Alexander Proyer about their mission to recover the meteorite and why it is important.

Why is discovery in Botswana so important?

Alexander Proyer: Meteorites are fragments of asteroids comets fallen to the surface of the earth. Finding a new one is rare but what makes this case truly sensational is not the fall itself but the fact that we knew it was going to happen. Usually, people are taken by surprise, seeing a flash of light or a fireball when the asteroid enters the atmosphere. But this one was observed in the space eight hours before its collision with the Earth.

The asteroid was first detected by a network of observatories – NASA's planetary defense network – which searches the night sky for objects. In this case, Richard Kowalski of the Catalina Sky Survey in Arizona discovered the extremely low light of an object moving in space.

This was the third time in history that such an observation and prediction was possible. only the second time that a fragment has been recovered. The first discovery came from an asteroid called TC3 in Sudan

Fulvio Franchi: We can view this event as a free delivery of material from the space that would otherwise require a very expensive space mission to be recovered .

Most meteorites are extremely old rocks, dating back to the birth of the solar system about 4.56 billion years ago, and come from the asteroid belt – small and large objects made of stone, metal and carbon. Jupiter. These asteroids keep a "record" of the planet's formation processes – such as growth by gravitational attraction, warming, and fusion – a record that is no longer available on Earth because it has been over-written by the processes tectonics operating on our planet.

Meteorites are fragments of our Moon or Mars, which have been catapulted into space by major events. They are even rarer than regular asteroids. One can appreciate the value of these asteroids by simply considering the costs of a space mission on the Moon, Mars or even the asteroid belt, to obtain such samples. This find is a real gift for the international consortium, in the process of training to perform lab badyzes of this and other fragments yet to be found during ongoing research.

What happened after it was detected?

Alexander Proyer: After Kowalski In Arizona, he alerted other institutions that are part of NASA's planetary defense network and calculated the size and trajectory of the body, concluding that an asteroid of 2 to 3 meters in diameter was about to touch the Earth in Botswana.

Fulvio Franchi: Colleagues from South Africa and Finland then contacted us, providing valuable information to locate the fragments. We immediately became aware of the importance of this event and mobilized the first research team

The fragments of the asteroid LA 2018 – scattered over the vast territory of the Kalahari Nature Reserve in Botswana, blown up by the wind when falling. Detailed calculations, by two independent groups, of the scattered field allowed our group of researchers to finally find a fragment of the asteroid

What was the procedure for its recovery and what were the challenges that you faced ?

Fulvio Franchi: There were some factors to consider when recovering this meteorite in Botswana.

First, you can not just take a meteorite and possess it – at least not legally. Meteorites are considered relics by law and must be returned to the National Museum.

Secondly, the planned drop zone was in a national park, the Central Kalahari Game Reserve. This required permits for entry and work.

Third, the Botswana Geoscience Institute is the one that has the mandate to act when unusual events like this occur. Naturally, he was involved in research.

The main technical challenges were to refine the research area. This was done using eyewitness observations and video equipment, mainly security cameras. Information on changes in direction and strength of winds, from 27 km above ground – where the meteorite exploded – to near the surface, was crucial.

The last challenge was getting out of the way. days in the territory of lions and elephants, snakes and scorpions. We had Park Rangers with rifles that were walking and camping with us, and fortunately the only losses were a number of blown tires. An unexpected challenge was to have at first sight millions of other objects resembling a generally dark meteorite: pieces of burned wood (from bush fires) or animal droppings. But the excitement of finding something of scientific interest, and the joy of adventure, kept us moving.

Why is it important to study the meteorite?

Alexander Proyer: There are several important reasons. is a puzzle piece to understand our solar system. The asteroids from which they originate represent different stages ranging from dust to small bodies via planetesimals (small planets), which have never reached the final stage of a single planet. One could say that different steps towards the formation of complete planets are preserved.

Some of them were broken again by collision with other asteroids and now expose their interiors. Samples of such depths are impossible to obtain on Earth or on any other untouched planet. They are absolutely unique and help us understand the inner workings of the Earth and other planets, which were built from very similar materials, but are now strongly differentiated into a core, mantle and crust.

In terms of planetary defense, we now have second case of remote observation of an asteroid related to a recovered material from it. If we ever have to defend ourselves against larger asteroids in the future, it is essential to know what kind of asteroid enters and whether it is likely to disintegrate, at least in part, in the atmosphere or to be hit by a defense missile. By studying the meteorites of the 2018 LA asteroid, it will be possible to relate the properties of meteorites determined in the laboratory to remote observations before impact of the asteroid.

Fulvio Franchi: More detailed badyzes, looking at the chemical composition of the rock and the possible content organic molecules, will also give us clues as to how life on earth has formed and ultimately on the great question: is there a life there?