Bacubirito, recognized as one of the five most massive meteorites in the world by the American Meteorite Society, has been on this list since its discovery in 1869. Even more, from 1869 to 1920, it was considered the largest meteorite in the world. Various estimates of its mass have been made over time, ranging from rudimentary calculations to precise measurements in recent years, fluctuating between 60 tons and the current 19.95 tons. This variability in mass measurement underscores the inherent complexity in calculating this crucial data in meteoritic science.
Calculating the mass of any object, including a meteorite, involves the product of its density and volume. Although the density of the Bacubirito meteorite can be considered constant, calculating its volume presents a significant challenge due to its irregular shape. Photographs of the meteorite reveal a complex structure, far from simple geometric shapes like a cube or cylinder, which greatly complicates the estimation of its volume.
The history of Bacubirito's mass measurements illustrates the methodological advances in this field. Originally, in 1869, its mass was overestimated as its full length was not considered, since a large part of the meteorite remained buried. With a length of 4.1 meters, this giant was partially hidden. Later, Dr. Ward, in 1902, provided an estimate of 50 tons after unearthing it, based on a very rudimentary estimation. Subsequently, in 1975, Dr. Buchwald, using photographic techniques in Culiacán, calculated its volume and, therefore, a mass of 22 tons. Finally, in 2018, researchers from the Autonomous University of Sinaloa employed innovative methods, precisely determining the mass at 19.43 tons.
The advanced method used by the Sinaloa researchers consists of mapping the surface coordinates of the meteorite, using an electronic theodolite or a scanner. From the surface data, the volume is calculated using an integration algorithm based on Green's Theorem. This technique also allowed for the accurate measurement of the meteorite's length along any of its axes, confirming its length of 4.1 meters.
In summary, the complex structure of the Bacubirito meteorite has not only posed a considerable challenge in accurately determining its mass, but also symbolizes the significant contribution of meteorites to scientific knowledge. These fragments of the cosmos, in their uniqueness, are invaluable sources of information about the fundamental characteristics of more massive celestial bodies, such as planetoids and asteroids. Moreover, they provide a unique window into understanding the composition and internal structure of the Earth itself, allowing scientists to infer about processes and materials that would otherwise be inaccessible.
Mexico, in particular, stands out for its rich collection of internationally significant meteorites, with Bacubirito being one of the most prominent examples. The presence of these meteorites on Mexican territory is not only a testament to the country's geological richness but also represents an invaluable opportunity for global scientific research. The study of these celestial bodies in Mexico significantly contributes to our understanding of the universe, offering essential perspectives on the history and evolution of the solar system. Thus, Bacubirito and other similar meteorites are not only objects of scientific curiosity but also symbols of the interconnection between our planet and the vast cosmos that surrounds it.
Emiliano Teran
*If you want to know more about the data in the figure at the beginning of the blog, I suggest reading the first article in the list of references.
References
Terán-Bobadilla, E., Abundis-Patiño, J. H., Añorve, C., Moraila, C. R., Ortega-Gutiérrez, F., & Aragón-Calvo, M. A. (2017). On a novel geometric analysis of the Bacubirito meteorite. Earth, Moon, and Planets, 120, 101-111.
Terán-Bobadilla, E., Abundis-Patiño, J. H., Añorve-Solano, C., Moraila-Valenzuela, C. R., & Ortega-Gutierrez, F. (2018). Bacubirito: the longest meteorite in the world. Astronomy & Geophysics, 59(2). https://doi.org/10.1093/astrogeo/aty084
Terán, E. (2019). Bacubirito: An Outstanding Cosmic Sample on Earth. Geospatial Analyses of Earth Observation (EO) Data, 93.