It is thought that more than a hundred tons of cosmic debris enters the Earth's atmosphere every day, mostly in the form of micrometeorites, dust-to-gravel sized particles. Most particles entering the upper atmosphere are derived from the tails of comets, but others are remnants of the original protoplanetary disc from which the Solar System formed, or fragments from the surface of other planets or moons, knocked free by earlier impacts. When these objects enter the atmosphere, they generally do so at very high velocities, causing them to heat rapidly as they pass through the atmosphere, and causing their surfaces to melt and the surrounding gasses to ionise. This can result in a bright streak across the sky called a meteor.
Larger bodies penetrate further into the atmosphere, burning longer and brighter, with those a few tens of centimetres in diameter producing meteors brighter in the sky than the planet Venus, which are termed 'fireballs'. Particularly large fireballs can sometimes be seen to visibly disinitegrate, and are known as bolides. The break up of such bolides is often audible from the ground, although, since they are typically tens of kilometres high, the sound typically reaches observers some time after the visible meteor, which can be confusing.
In a paper published in the South African Journal of Science on 29 May 2025, Roger Gibson of the School of Geosciences at the University of the Witwatersrand, Timothy Cooper of the Comet Asteroid and Meteor Section of the Astronomical Society of Southern Africa, Leonidas Vonopartis, also of the School of Geosciences at the University of the Witwatersrand, Carla Dodd of the Department of Geosciences and Institute for Coastal and Marine Research at Nelson Mandela University, Peter Hers of the Garden Route Centre of the Astronomical Society of Southern Africa, and Lewis Ashwal and Robyn Symons, once again of the School of Geosciences at the University of the Witwatersrand, describe a bolide event which took place over the coastal belt between Mossel Bay and Gqeberha, and as far north as the southern Karoo, on 25 August 2024.
Slightly before 9.00 am on Sunday 25 August 2024, residents of the area between Mossel Bay and Gqeberha and the southern Karoo heard a noise described as like rolling thunder which persisted for more than 30 seconds, despite the sky being clear of thunderclouds. Some residents of this area also reported ground tremors.
This provoked a great deal of speculation on social media, with people hypothesizing an earthquake, landslide, vehicle collision, aircraft crash, gas or electrical infrastructure explosion, or other events. At 9.02 am, Zoë van der Merwe of Cape St Francis posted a a cluster of rapidly moving, bright, silver-white fireballs in the sky that extinguished within seconds in the general vicinity of Gqeberha.
There is currently a global effort to better understand atmospheric fireball events, involving organisations in many different parts of the world. In Southern Africa, the Astronomical Society of Southern Africa maintains a database of fireball events, with a dedicated webpage where members of the public can report events. They also actively seek out reports of fireballs on social media, and quickly became aware of Zoë van der Merwe's post, and other reports of the Nqweba event, leading them to share reporting guidelines on social media groups. They also received reports of a bulletin on Luister FM, a radio station based in Port Elizabeth, which stated that a meteorite had been observed falling into the sea off the Eastern Cape at around 8.55 am.
Armed with these sources of data, they set out to determine whether the observed objects were in fact derived from a Solar System body, rather than being Human-made space junk re-entering the atmosphere. This is less complex than it sounds, as space junk will typically enter the atmosphere at a low angle and with a slow velocity, most often as a series of such events as debris from the same object falls to Earth. The Nqweba object did not fit this profile, and its occurrence did not coincide with any known satellite debris re-entering the atmosphere, making unlikely that it was space junk.
Initial reports all suggested that the bolide was moving out to sea, possibly splashing down in Jeffreys Bay, to the west of Gqeberha. As more reports came in it became it had been seen over a much wider area, north as far as Petrusburg, and west as far as Ceres. A further three videos of the object emerged, although the one taken by Zoë van der Merwe appears to cover the final part of the meteor's journey.
Shortly before 9.00 am, residents of Nqweba (formerly Kirkwood), about 100 km to the north of Cape St Francis, heard what they described as a loud thunderclap, followed by a long rumbling noise. Slightly after this, 9-year-old Eli-zé du Toit observed something falling through a large Wild Fig tree in her parents garden. When investigated, this turned out to be a rock smaller than her fist, with a shiny black crust, broken in places to reveal a light grey, concrete-like interior. When touched, the exterior layer of this rock was hot, while the interior was cold. Eli-zé's mother, Jesica Botha, posted several images of this and other fragments found in the garden to social media groups, leading to her being contacted by Carla Dodd of Nelson Mandela University.
Carla Dodd was able to arrange for the meteorite fragments to be transported to Nelson Mandela University for safekeeping; meteorites, along with fossils and archaeological artefacts are protected in South Africa by the National Heritage Resources Act (1999). Here the fragments were weighed, examined and placed into desiccators for storage. This preliminary inspction suggested that the fragments belonged to a type of stoney meteorite called a HED (howardite–eucrite–diogenite) achondrite breccia. These meteorites resemble terrestrial igneous rocks, and are therefore presumed to have come from bodies large enough for magma differentiation and igneous processing to have occurred.
Initial witness reports, and the two sites where meteors were reported to have fallen to Earth, Nqweba and the sea off Cape St Francis, are about 100 km apart, suggesting that the bolide had followed a north-south trajectory, shedding fragments as it went, towards the sea. However, bolides are notoriously confusing for observers, due to the long gap between the visual fireball and the sound reaching witnesses. Careful examination of witness reports and data from remote observation stations eventually led Gibson et al. to conclude that the bolide moved southwest-to-northeast, first appearing off Mossel Bay and moving inland towards Nqweba.
The Nqweba Bolide was the 20th bolide recorded globally in 2024, and one of the smallest. It is thought to have been about 1 m in diameter when it entered the atmosphere, and to have released energy equivalent to that released by the detonation of 92 tons of TNT.
Since 1992, 493 fireball events have been recorded over South Africa, only about 3% of which have been visible during the day. The largest recorded bolide in Southern Africa was the 21 November 2009 event over northern South Africa and southern Botswana, which was probably about 200 times as large as the Nqweba Bolide, although no fragments of this were ever found.
Recovered meteorites in South Africa are strongly linked to observed meteorites, and particularly daytime events, with 21 of 51 known meteorites collected in South Africa connected to observed falls, 75% of these in the daytime. However, prior to the Nqweba Bolide, the most recent of these fell on Lichtenburg, North West Province, in 1973, long before modern technology such as remote observation stations and mobile phones was available to help track these events.
South Africa is currently increasing its remote observation capacity, and therefore its ability to track fireballs. It is currently home to 16 cameras running under the auspices of the NASA SETI Institute Cameras for Allsky Meteor Surveillance network, and a further ten operated by the Global Meteor Network (4 of which have been installed in Western Cape schools to promote STEM activities). These are already improving fireball-detection rates, but do not work well in daylight. The collection of meteorite fragments is largely dependent on direct observation of the objects falling, as was the case with the Nqweba Meteorite Fall, but networks of cameras can help triangulate the area in which meteorites might have fallen, improving the chances of finding meteorites which were not directly observed.
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