^1,2Peter Jenniskens et al. (>10)
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14337]
¹SETI Institute, Mountain View, California, USA
²NASA Ames Research Center, Moffett Field, California, USA
Published by arrangement with John Wiley & Sons

The Aguas Zarcas (Costa Rica) CM2 carbonaceous chondrite fell during nighttime in April 2019. Security and dashboard camera videos of the meteor were analyzed to provide a trajectory, light curve, and orbit of the meteoroid. The trajectory was near vertical, 81° steep, arriving from an ~109° (WNW) direction with an apparent entry speed of 14.6 ± 0.6 km s−1. The meteoroid penetrated to ~25 km altitude (5 MPa dynamic pressure), where the surviving mass shattered, producing a flare that was detected by the Geostationary Lightning Mappers on GOES-16 and GOES-17. The cosmogenic radionuclides were analyzed in three recovered meteorites by either gamma-ray spectroscopy or accelerator mass spectrometry (AMS), while noble gas concentrations and isotopic compositions were measured in the same fragment that was analyzed by AMS. From this, the pre-atmospheric size of the meteoroid and its cosmic ray exposure age were determined. The studied samples came from a few cm up to 30 cm deep in an object with an original diameter of ~60 cm that was ejected from its parent body 2.0 ± 0.2 Ma ago. The ejected material had an argon retention age of 2.9 Ga. The object was delivered most likely by the 3:1 or 5:2 mean motion resonances and, without subsequent fragmentation, approached the Earth from a low i < 2.8° inclined orbit with a perihelion distance q = 0.98 AU close to the Earth’s orbit. The steep entry trajectory and high strength resulted in deep penetration in the atmosphere and a relatively large fraction of surviving mass.