Water existed on Mars at least 700 million years ago, with evidence that had long been hidden away in a box.

The Lafayette meteorite was discovered in a box at Purdue University in 1931. Unfortunately, scientists still do not know how it ended up there, but the find turned out to be significant. A new analysis of the rock revealed evidence of liquid water on Mars 742 million years ago, according to Live Science.

It is known that the meteorite is a glassy piece of cosmic rock measuring only about 5 centimeters in length. It was found in a box nearly 100 years ago, but no one can say where it came from or who first discovered it. Only in the 1980s did scientists realize that the gases trapped inside the mysterious rock correspond to the atmosphere of Mars, as measured by NASA's Viking landers.

Earlier studies also showed that the minerals in the meteorite interacted with liquid water during their formation. However, scientists were unsure when these minerals formed. New research has shed light on this mystery.

According to the lead author of the study, Marissa Tremblay, an assistant professor in the Department of Earth, Atmospheric, and Planetary Sciences, their analysis suggests that the meteorite's minerals are less than a billion years old. The researchers note that they do not believe there was a significant amount of liquid water on the surface of the Red Planet at that time; however, they think that water emerged as a result of melting nearby subsurface ice known as permafrost. At the same time, the melting of the permafrost was likely triggered by magmatic activity, which still occurs on Mars today.

In their study, the scientists used changes in argon molecules within the minerals to determine the most accurate current age of the mineral formation. The team also considered the heating the meteorite might have experienced after being ejected from Mars 11 million years ago. They also examined the potential effects of its transit through space and subsequent journey through Earth's atmosphere.

The researchers note that the exact timing of the meteorite's arrival on Earth is unknown; however, they studied trace amounts of fungus on the surface of the space rock. Combined with unverified reports of a student witnessing the stone's landing while fishing, scientists believe the meteorite may have landed on Earth around 1919.

Scientists point out that several factors could have influenced its age:

• the collision that ejected Lafayette from Mars;
• the heating it experienced while drifting in space for 11 million years;
• the heating during its fall to Earth;
• the passage through Earth's atmosphere.

At the same time, researchers have demonstrated that none of these factors actually affected the age of the changes in the water environment in Lafayette. Confirming the date of the meteorite's interaction with liquid water not only sheds light on Mars' history but also suggests that the same methods can be applied to other meteorites found on Earth or samples brought back from missions to other planets, moons, and asteroids. In simple terms, scientists have discovered an effective way to date mineral changes in meteorites that can be applied to other meteorites and planetary bodies.