The study identified when water interacted with the meteorite and established that the dating was unaffected by events after it left Mars.

A sliver of Martian rock that once lay hidden in a university drawer has helped researchers better understand the Red Planet’s geological history. Using isotopic dating, a team at Purdue University has determined that the “Lafayette Meteorite” likely interacted with liquid water approximately 742 million years ago.

Researchers from Purdue University have confirmed the so-called Lafayette Meteorite encountered Water before it left Mars behind. The unlikely journey that brought the Lafayette Meteorite to Purdue University’s Department of Earth,

Despite the team's success in dating the water-rock interaction, the researchers don't think Mars was teeming with water at that time in history. Rather, they suspect the water came from permafrost melt, perhaps caused by molten rock moving through the planet's crust. The study appears in the Geochemical Perspectives Letters.

Scientists have traced the origins of the Lafayette Meteorite back to Mars, dating its water-altered minerals to 742 million years ago. The findings suggest that the meteorite's interaction with water came from melting subsurface permafrost rather than surface water,

"We think the water came from the melting of nearby sub-surface ice called permafrost, and that the permafrost melting was caused by magmatic activity that still occurs periodically on Mars to the present day.

The Lafayette meteorite was discovered in a drawer at Purdue University in 1931, with no clear indication of how it got there. A new analysis of the rock reveals evidence of liquid water on Mars 742 million years ago.