An international team of researchers has published the results of a study of the so-called Lafayette meteorite. It interacted with liquid water on Mars just 742 million years ago.
The Lafayette meteorite has a rather complicated history. It was found in a desk drawer at Purdue University in 1931. But it is not entirely clear how it got there. Presumably, it was found by a student who witnessed the meteorite fall into the pond where he was fishing. He retrieved it from the dirt and then handed it over to the university as a gift.
Even during early studies of the meteorite, scientists hypothesized that it was of Martian origin. This hypothesis was confirmed after the Viking mission transmitted to Earth the results of isotope content in Martian rocks. This confirmed the origin of a number of meteorites, including Lafayette.
The scientists’ analysis showed that the Lafayette meteorite was ejected from the surface of Mars about 11 million years ago as a result of an asteroid impact. Afterwards, it traveled around the Solar System for a while before falling to Earth.
While studying the Lafayette meteorite, scientists also found irrefutable evidence that it interacted with liquid water. The main question was when exactly it occurred. To find the answer, an international team of scientists determined the age of minerals in the meteorite that formed when liquid water was there.
Dating showed them to be 742 million years old, which is relatively young by Martian standards. The Red Planet is thought to have had seas and even an ocean about 3.5 to 4 billion years ago, after which its climate changed, and it lost most of its atmosphere and water.
The researchers said they did not think there was much liquid water on the surface of Mars at the time the minerals were formed. It most likely resulted from the melting of nearby subsurface ice (permafrost) that was caused by volcanic activity. According to the scientists, their dating is accurate. It could not have been affected by the impact that ejected the meteorite from Mars, nor by the effects of its stay in space, nor by the heating it experienced during its entry into Earth’s atmosphere, nor by its subsequent interaction with Earth’s water.
Earlier we covered the results of another Martian meteorite that turned out to be rich in organics.
Provided by Phys.org
