This Saturday, June 2, an asteroid detected in space few hours earlier hit the ground on Botswana, in southern Africa. Its atmospheric passage was recorded by at least three cameras in South Africa. A huge bolide that illuminated the sky, and was also seen by dozens of people on that area. After analyzing the videos and data released by JPL / NASA, we believe there may be more than one ton of meteorites on ground.
Asteroide pode ter deixado mais de uma tonelada de meteoritos em solo na Botswana
Tempo de leitura: 5 min
According with the telescope observations of the Catalina Observatory in the United States, it was between 3 and 4 meters in diameter and on Wednesday (06) JPL / NASA released data from the infrasound network regarding this event. According to JPL, the asteroid entered the atmosphere with a speed of 16.9 km/s, its main explosion occurred 28.7 km in altitude and released an energy equivalent to about 980 metric tons of dynamite.
Using this data we can trace its approximate path through the atmosphere and estimate a possible area of the meteorites dispersion. The result can be seen in the map below, wich match with initial projection of SONEAR. The hottest areas are, according to our estimates, the places where the largest masses from this asteroid can be found. The coldest areas and also bigger ones are the places were the smaller masses must be dispersed, but in a greater quantity.
We also did some simulations, using different mass and density estimatives, to get an approximation of the amount of meteorites that may have arrived on the ground.
From the energy measured by JPL NASA, we can conclude that the asteroid entered our atmosphere with a mass of about 40 metric tons. We work on different models depending on their density. This mainly determines the way fragmentation occurs. Objects denser and resist more and have a more constant fragmentation. For less dense objects, a much more intense fragmentation is common.
Because of the brightness profile observed in the Botswana bolide, we believe that it’s not a metallic object, normally denser.
The most common type of meteorite found on earth, the chondrite, has a density around 3.8 g / cm³. With this density the asteroid should be about 2.7 m in diameter. We then simulated using the mean density of a carbonaceous meteorite, 2.5g / cm³. For this density the asteroid should be approximately 3.4 m in diameter to generate an energy equivalent to that detected by JPL.
For both cases, in our simulations, the resulting mass exceeds one metric ton. Obviously, since we do not have accurate data the results are also imprecise. But we are likely to have about one metric ton of meteorites from this asteroid.
Ten years ago a similar case occurred in Africa. The asteroid 2008 TC3, 18 hours after being detected by the Catalina telescopes, fell in Sudan. But the expeditions to the place recovered only 4 kg of meteorites. Who knows now the expeditions to the fall place are luckier?
As “science lovers” we know the importance of finding these meteorites. For the first time in history an asteroid detected in space was filmed burning in atmosphere. Your meteorites can confirm the accuracy of our mathematical models, or maybe can help improve them.
Last modified: Thursday July 12th, 2018