A team of international researchers has analyzed data freshly gathered by the Mars Express mission, and offered new insight into the mineral composition of Mars, scientists said Monday.

This new research, published online in the journal Science, points out promising places to search for evidence of past life, according to John Mustard, an associate professor of geological sciences at Brown University, who took part in the research.

Mars Express, Europe's first mission to the Red Planet, has generated a slew of new data about the mineral composition of the planet's dry, dramatic surface. In six new papers, the international team revealed clues about the planet's past hidden in the rock.

Mustard said this research shows areas that contain water or may have otherwise been amenable to life forms millions of years ago.

"If you want to resolve the big question about life on Mars, you want to go to the right places and get samples," Mustard said in a press release. "The new research tells us where some of those places may be."

Researchers found a diverse and complex mix of surface materials: silicates, ices and frosts, and hydrated minerals and sediments.

Some areas, such as Terra Meridiani where the US Mars rover Opportunity now operates, were rich in acidic sulfates. Rocks in other places, for example around the Syrtis Major volcanic plateau,were richer in clay and hydrated minerals. These are more neutral in pH, and thus more likely to support life.

They also found kieserite, gypsum and polyhydrated sulfates, all sulfate minerals that contain water in their crystal structure,in canyons and buttes around the planet.

This shows that water was common and widespread during the first billion years of Mars' roughly 4.6-billion-year history. These minerals were even found inside Valles Marineris, the largest canyon in the solar system.

Moreover, researchers found the rock-forming mineral olivine as well as low- and high-calcium pyroxene across the Mars surface. They expected to find hydrated minerals in the northern lowlands because of a theory that an ancient ocean once covered these rolling plains.

But data collected by OMEGA, a spectrometer aboard Mars Express using visible and infrared light to map the surface composition of the planet, showed that the northern lowlands are composed of volcanic rock not altered by water, making the ocean theory less likely.

Based on these findings, scientists said Syrtis Major, Valles Marineris and Terra Meridiani would all be strong candidates for rock and soil sampling for future Mars missions. They also designed a next-generation spectrometer that will be on board the Mars Reconnaissance Orbiter, which NASA plans to launch in August.