An asteroid struck Mars 11 million years ago, sending pieces of the planet hurtling through space, one of which eventually crashed into the Earth near Purdue and is known as the Lafayette Meteorite. Recently, scientists have determined the age of minerals in the Lafayette Meteorite that formed when there was liquid water present on Mars. This discovery sheds light on the timing of liquid water interaction on the red planet and the processes that led to its formation.
Marissa Tremblay, an assistant professor at Purdue University, led the study using noble gases like helium, neon, and argon to study the physical and chemical processes on Earth and other planets. By dating minerals in the Lafayette Meteorite, the team found that they formed 742 million years ago, indicating the presence of liquid water on Mars in the planet’s geologic past. This water is believed to have come from the melting of subsurface ice called permafrost, caused by periodic magmatic activity on Mars.
The team demonstrated that the age obtained for the timing of water-rock interaction on Mars was robust and unaffected by external factors such as the impact that ejected the Lafayette Meteorite from Mars or its exposure to heat during its journey through space and entry into Earth’s atmosphere. Co-author Ryan Ickert also emphasized the unique evidence of water interaction in the meteorite and the importance of dating this interaction to understand the geologic history of Mars accurately.
Meteorites like the Lafayette Meteorite serve as time capsules from celestial bodies in our universe, carrying valuable data that can be unlocked by geochronologists. They are distinguished from Earth rocks by characteristics such as density, metal content, and magnetic properties, as well as features like fusion crust formed during atmospheric entry. This international collaboration of scientists involved in the study is essential for advancing our understanding of planetary geology and the history of Mars.
The Lafayette Meteorite’s post-Earth timeline, from its landing at Purdue University in 1931 to its origin on Mars 11 million years ago, has been partially explained through research. By analyzing organic contaminants on the meteorite that match Earth’s crop diseases from specific years, scientists have narrowed down the possible time of its fall and gained insights into whether the meteorite’s descent was witnessed by anyone. Continued research into meteorites and their histories will further our knowledge of the solar system’s evolution.
The study of alteration minerals in meteorites, such as those in the Lafayette Meteorite, is critical for understanding the presence of liquid water on planetary bodies like Mars. This research, made possible by the Stahura Undergraduate Meteorite Fund at Purdue University, will allow scientists to continue unraveling the geochemistry and histories of meteorites, with undergraduates playing a role in assisting with this important work. The findings from this study contribute to the broader field of planetary science and offer valuable insights into the geologic processes that have shaped Mars and other celestial bodies in our solar system.