A piece of Martian rock once hidden in a university drawer has helped researchers better understand the geological history of the Red Planet. Using isotopic dating, a team from Purdue University has determined that the ‘Lafayette Meteorite’ likely interacted with liquid water about 742 million years ago.
However, it was a long journey to this discovery, which partly happened by chance. About 11 million years ago, an asteroid collided with Mars, sending plumes of debris beyond the planet’s atmosphere. One of those meteorites finally succumbed to Earth’s gravity after a long journey through space, sending it on a trajectory that ended in Indiana. Although the exact dates of its arrival and discovery are unclear, the penny-sized piece of rock somehow found its way to a Purdue University Desk drawer of the biology department, where the faculty discovered him in 1929.
Somewhere in the eighties, nameless parties donated the Lafayette meteorite (named after the location) to Chicago’s Field Museum. There, experts linked the gases trapped in the rock to the gases detected in the Martian atmosphere by NASA’s Viking spacecraft. Additional analyzes showed that minerals in the meteorite interacted with liquid water on Mars at some point, although no specific time frame could be determined.
That mystery appears to have finally been solved thanks to researchers from Purdue University’s Department of Earth, Atmospheric, and Planetary Sciences (EAPS). In a study published on November 14 in Geochemical perspective lettersThe experts explained that isotopic dating and analysis provide chemical evidence that the Lafayette meteorite most likely interacted with liquid water as the rock first formed about 742 million years ago. But that doesn’t mean Mars necessarily harbored huge oceans and rivers – or at least not at that time.
“We don’t think there was abundant liquid water on the surface of Mars at that time,” said Marissa Tremblay, an assistant professor at EAPS and lead author of the study. said in a university profile earlier this month. “Instead, we think the water came from the melting of nearby underground ice called permafrost, and that the melting of the permafrost was caused by magmatic activity that still occurs periodically on Mars to this day.”
Researchers also made sure to take into account possible contamination that may have occurred while the meteorite spent 11 million years in space.
“The age could have been influenced by the impact that ejected the Lafayette meteorite from Mars, the warming that Lafayette experienced during the 11 million years it was in space, or the warming that Lafayette experienced when it fell to Earth and created a burned out a bit. in the Earth’s atmosphere,” Tremblay explained. “But we were able to show that none of these things affected the age of aqueous change in Lafayette.”
Researchers believe that similar dating methods could be applied not only to other meteorites, but also to planets in the future. By doing this, they hope to possibly discover evidence of water elsewhere.