PASADENA. California. Oct 9: The Mars Pathfinder has yielded what scientists said is the strongest evidence yet that Mars, like Earth, has a crust, a mantle and an iron core — lending support to the theory that the Red Planet might once have been hospitable to life, report AP

The evidence that the planet is not merely a solid ball of rock came from analyzing radio signals from Pathfinder as Mars spins on its axis.

Having enough heat to create these distinct layers gives weight to the theory that Mars once may have been warm and wet enough for life to evolve, as it did on Earth. Mars formed 4 billion years ago.

William Folkner, a scientist at NASA's Jet Propulsion Laboratory. said Wednesday that scientists do not yet know

whether that iron core is solid or molten like Earth's. However, they know it is smaller, at somewhere between 800 miles (1,280 kilometers) and 1,247 miles (1,995 kilometers) In radius. Mars' full radius is 2,113 miles (3,381 kilometres).

Molten cores are rare; of the planets, only Earth and Mercury are known to have one. Jupiter’s moon Ganymede is thought to have one. too. The motion of liquid metal in the Earth's core is what creates the magnetic field around our planet. By contrast, our moon is solid and "dead.”

So far. the orbiting Mars Global Surveyor has found evidence of a weak magnetic field at the Red Manet, but Pathfinder scientist Matthew Oolombek said those observations are not necessarily evidence that the magnetic field

was generated by the interior or that the core is liquid today.

Scientists still remain a long way from finding another component of life — water.

But they have detected signs that the surface once teemed with water flowing in streams and deep channels that carried rocks from place to place. Pathfinder yielded close-up Images of martian rock conglomerations that showed small spheres, probably pebbles smoothed by water.

Wes Ward, a Pathfinder scientist from the US Geological Survey in Flagstaff. Arizona, also said he has seen the first signs of true sand on Mars, with grains about 1 millimetre in size. A product of weathering and erosion, they lie in dunes and in fluted Patterns like desert sands on Earth.