First meteorite (17.92 g) of Botswana bolide of 2018 LA (2 June 2018) found in Central Kalahari Game Reserve, Ghanzi, Botswana
On 23 June, after five days of searching and on the last day of the planned search expedition, a team from Botswana, South Africa, Finland and the USA discovered the first meteorite (17.92 grams) most likely in the northern part of Botswana’s Central Kalahari Game Reserve (CKGR) in Ghanzi district. The meteorite, which could be an achondrite, was found by geologist Lesedi Seitshiro (BIUST) who joined the search expedition as a volunteer. The search team was lead by Alexander Proyer (BIUST) and consisted of geoscientists from Botswana International University of Science and Technology (BIUST), Botswana Geoscience Institute (BGI) and University of Botswana’s Okavango Research Institute (ORI), including Peter Jenniskens (SETI), Professor Roger Gibson (Head of School at the School of Geosciences at the University of the Witwatersrand in Johannesburg, South Africa) and Tomas Kohout (FFN / University of Helsinki). The meteorite fell during the 2 June bolide of asteroid 2018 LA (ZLAF9B2) over South Africa and Botswana at ~18:49:17-23 local time (UTC+2). The potential strewn field had been calculated independently by a team consisting of members of the SETI Institute in California and by Esko Lyytinen and Jarmo Moilanen of the Finnish Fireball Network (FFN). The results of the analyses were found to be almost identical and then combined. The calculated 200-km² strewn field is said to be about 2 km wide and crosses one of the main roads between the northern and the central part of the CKGR. The meteorite was found in the area of the calculated strewn field where small meteorites the size of the found specimen are expected to have fallen. Before the search expedition Jenniskens and Oliver Moses (ORI) had gathered available security surveillance videos in Rakops and Maun, Botswana. Especially the one from Rakops turned out to be useful for analysis. The available images were calibrated based on background stars by Jim Albers. Tim Cooper of the Astronomical Society of South Africa (ASSA) calibrated the videos to the south. Jelle Assink and Laslo Evers of the Royal Netherlands Meteorological Institute (KNMI) provided the important atmospheric wind data for the dark flight analysis.
Meteorites found in Botswana (as ‘relics’) are protected under Botswana law (Volume: XIII, Monuments and Relics, Chapter: 59:03) and must not be removed or exported according to Mohutsiwa Gabadirwe‚ senior curator of the Botswana Geoscience Institute. The search for more meteorites is going on, a fourth search expedition is said to start soon. A second search team includes Dr Fulvio Franchi (BIUST) and Tomas Kohout (FFN / University of Helsinki). Found meteorites will be curated at the Botswana National Museum. A research consortium has been established consisting of scientists from Botswana‚ South Africa‚ Finland‚ and the USA.
The meteorite presented at the press conference at the University of Botswana. Photo (left): University of Botswana. Photo: (right): Onalenna Dube
Members of the first search team. Mohutsiwa Gabadirwe (left background), Lesedi Seitshiro (center left), Alexander Proyer (center background), Peter Jenniskens (center right), Oliver Moses (right) and members of the search team at the find location. Photo: Peter Jenniskens
A found meteorite. Photo: Sanni Turunen/ Helsinki University
Tiyapo Ngwisanyi of Botswana Geoscience Institute (BGI), Alexander Proyer (BIUST), Mohutsiwa Gabadirwe (BGI) and Oliver Moses (ORI) are giving information about the meteorite, the meteorite search and future plans in a press conference at the University of Botswana. Video: Gabzfm News (published 6 July 2018)
Online media coverageThe bolide of asteroid 2018 LA
CCTV recording by Barend Swanepoel and Wikus van Zyl recorded from Swanepoel’s father’s or his father’s friend’s farm near location -26.743643, 26.223267 between Hartebeesfontein and Ottosdal, South Africa.Video from Randfontein, Gauteng (-26.1541°, 27.6800°)
Video of the bolide by B. Lombard. Camera location: -24.6459°, 25.8157°
CCTV recording of the bolide by O. Delport from camera location -26.7229°, 22.3395°CCTV camera of ‘Kuruman Radiators’ in Kuruman, South Africa at location -27.471877, 23.432932 (time is wrong). Video: Christian Matthys Grobler The bolide from camera location -24.6225°, 25.9158° in Gaborone Botswana. Photo: Dhiraj Sharma
The Apollo NEO 2018 LA / ZLAF9B2 was discovered at 8:14 UTC by the Mount Lemmon Survey (MLS)/Catalina Sky Survey, 8.5 hours prior to impact.
Orbit data of 2018 LA (JPL Small-Body Database)
Bill Gray’s Pseudo-MPEC for ZLAF9B2.
Dhiraj S provided this AMS observation report about his sighting from location (24°37’21”S, 25°54’57”E) in Gaborone in the South-East District of Botswana at 16:44 UTC.
Peter Brown reports a “strong infrasound detection of a bolide at station I47 in South Africa today at 1730 UT. Origin time between 1645-17 UT over Botswana. Yield 0.3-0.5 kT, corresponding to 2m diameter asteroid.”