Carbonaceous Chondrite Rains Down In Costa Rica Part 1

Once in a while, on the order of decades to centuries, scientists and space rock enthusiasts are gifted with a freshly fallen meteorite of a rare class. These rare types could be a lunar meteorite, an iron type, a eucrite, a pallasite, or one of the other many more scarce classifications of meteorites. On April 23, 2019 in Costa Rica this is exactly what happened, the residents of Aguas Zarcas were startled by a massive fireball. Meteorite hunters were on the scene within twenty-four hours in a new type of gold rush to be the first person to find newly fallen space rocks. In just a matter of a few days scientists were given samples directly from the meteorite hunters and the classification came out to be a very rare type, a Carbonaceous Chondrite. This event was a perfect combination of a rare class of meteorite, cooperation from the locals and the country of where the stones landed, and a stroke of luck with the weather. The Aguas Zarcas fall was a scientist and meteorite lover's dream. 


A witnessed fall of a space rock is rare to begin with, the world might see and hunters could subsequently recover meteorites from three to five Bolide events per year. On top of that the country and city/village the rocks land in may not allow the space rocks to be recovered, sold, and taken out of the country. So the odds greatly diminish for many different factors playing against the space rock for the chances of being found and brought to scientists and collectors. In the case of the Aguas Zarcas, hunters, scientists, and collectors were able to purchase many kilograms of meteorites from the locals. The residents of Aguas Zarcas, after hearing about how people were paying for meteorites, became a meteorite hunting community. They learned the appearance of the meteorites and they took off searching for space rocks in their town and surrounding areas. The government had no restrictions on deporting the meteorites and in a matter of days scientists were given freshly fallen meteorites. 


The speedy recovery also allowed meteorite hunters to gather up space rocks that were not contaminated by rain. Some space rocks contain water within them. Aguas Zarcas is one such a meteorite that holds water. There's a theory that asteroids played a huge role in not only delivering the ingredients necessary for life but that they also delivered water to the young Earth. Collecting pre rain samples of Aguas Zarcas was extremely important to determine how much water this meteorite held. Any rain would have made it impossible to determine how much water was originally inside the stone. Oxygen and water begin to immediately contaminate and weather meteorites, they are the worst enemy of space rocks. Once the meteorite enters Earth's atmosphere weathering begins to terrestrialize the stone by a chemical process called oxidation. Water speeds up this process. Hunters are racing against the clock of mother nature to save as many meteorites as possible from rainfall, if the rocks fell in a wet environment. Luckily, in Costa Rica the rain held off for five days. This gave meteorite hunters time to gather as pristine as possible meteorite samples for scientists to analyze. Now they can classify the new space rock and perform other analysis on them.

 

 

 

 

https://meteorites.asu.edu/news/aguas-zarcas

https://www.scientificamerican.com/article/murchison-meteorite/

https://www.lpi.usra.edu/meteor/metbull.php?sea=Aguas+Zarcas&sfor=names&ants=&nwas=&falls=&valids=&stype=exact&lrec=50&map=ge&browse=&country=All&srt=name&categ=All&mblist=All&rect=&phot=&strewn=&snew=0&pnt=Normal%20table&code=69696