As per a latest study, a meteorite that was found last year in Sahara Desert is probably the first known piece of ancient Martian crust.

The Mars meteorite is named as NWA 7533 and is 4.4 billion years old. NWA stands for northwest Africa, where the rock was discovered.

The meteorite also contains proofs of asteroid strikes that occurred in earlier times, thereby telling that rock came from prehistoric and cratered southern highlands of the Red planet, said researchers.

Lead author Munir Humayun of Florida State University reveals, "We finally have a sample of the Martian highlands, that portion of Mars that holds all the secrets to Mars' birth and early development".

The age of the meteorite is determined by studying crystals lying in it, known as zircons, which were also formed about 4.4 billion years back.

High concentrations of elements, such as nickel, osmium and iridium, were also found in the meteorite. This shows that rock was formed in the region that was hit by chondritic meteors, which are quite enriched in these elements.

Humayun and his team were able to compute a thickness of crust of Red Planet by calculating the abundances of these elements. According to their estimation, Martian crust is 31 miles thick.

No mark of hydrous silicate minerals has been found in NWA 7533.