Scientists have found five new Martian meteorites.

The new rocks, which were blasted off the Red Planet in the distant past only to land on Earth at a later date, were recovered by expeditions to Antarctica and the hot deserts of Oman and the Sahara.

They bring the number of known stones from Mars to just 24. Scientists are fascinated by the rocks because they contain chemical clues about Martian history and the possibility that the planet once possessed oceans of water and life.

The recent cache includes six specimens, but two are believed to be chunks from the same meteorite. One of the pair weighs 13.7 kilograms (30 pounds) and is the second largest Mars meteorite fragment ever recovered.

Antarctica and the world's deserts have proved fruitful hunting grounds for meteorite collectors. The dark rocks from space are easier to pick out on snowy and sandy landscapes.

Martian suspect

One of the rocks was picked up by veteran Mars rock finders Bruno Fectay and Carine Bidaut of France. They found one now catalogued as NWA 1068, in the Western Sahara.