Aguas Zarcas, meaning “clear and pure water” in Spanish, is a fascinating 2019 witnessed fall, freshly arrived from Costa Rica.
This meteorite has already been identified by the Center of Meteorite Studies at Arizona State University (ASU) as a carbonaceous chondrite and is officially classified as a rare CM2. Aguas Zarcas boasts impressively intact and pristine fusion crust. Many stones were picked up during the first five days after its fiery arrival on Earth. On day six, rain fell across Costa Rica. Because of quick action by local villagers during those first five days, we now have a clear, empirical visual representation of the significant modification caused by a single rain and its dramatic effects on the fusion crust of just-fallen meteorites.
According to ASU, Aguas Zarcas presents initial similarities to Murchison (witnessed fall, Australia, 1969), but is actually quite distinct. From a scientific point of view, this is the first time since 1969 that there has been a large amount of Murchison-like material available for study and collection. As experienced collectors know, Murchison is one of the most-studied meteorites in history, making this new fall of particular interest to academics. Like Murchison, therefore, this meteorite is already in high demand.
Meteorite scientists have noted the stone’s highly brecciated structure. Some stones contain visibly chondrule-rich clasts; some contain large amounts of metal and will adhere to a magnet, while others do not. The variation in these specimens is a reflection of the heterogeneity of the parent body, caused by pummeling and re-accretion of other asteroidal material as it hurtled through space.
The Aguas Zarcas fall produced small, fusion-crusted stones, the majority of which were unbroken; a rare occurrence due to the violent effects experienced by most meteorites as they blast through Earth’s atmosphere.