Washington: A new study has helped scientists uncover the climate history of the 'red planet' with the help of an ancient Martian meteorite known as 'Black Beauty'.
Florida State University Professor Munir Humayun and an international research team found the evidence for the climate shift in minerals called zircons embedded inside the dark, glossy meteorite. Zircons, which are also abundant in the Earth's crust, form when lava cools. The secret to Mars' climate lies in the fact that zircons (ZrSiO4) contain oxygen, an element with three isotopes.
Humayun, a professor of geochemistry, said that first it was found that about 4.5 billion years ago, water was more abundant on Mars, and now they have learned that something dramatically changed that.
He further explained that now it could be concluded that the conditions that are seen today on Mars, this dry Martian desert, must have persisted for at least the past 1.7 billion years.
On Mars, oxygen has been distributed in the atmosphere (as carbon dioxide, molecular oxygen and ozone), in the hydrosphere (as water) and in rocks. In the thin, dry Martian atmosphere, the sun's ultraviolet light causes unique shifts in the proportions in which the three isotopes of oxygen occur in the different atmospheric gases.
The Black Beauty meteorite was discovered in the Sahara Desert in 2011. It's also known as NWA 7533, which stands for Northwest Africa, the location where it was found.
The study 'Record of the ancient Martian hydrosphere and atmosphere preserved in zircon from a Martian meteorite' is published in Nature Geoscience.