Nasa mission to search for Martian bugs
An American mission to Mars will focus on three key areas where alien life may once have thrived and gather samples to be returned to Earth.
The Mars 2020 mission will launch a rover to the Red Planet in three years' time to look for chemical relics of Martian bugs.
ExoMars Rover, a European mission also launching in 2020, will use similar techniques to search for life biosignatures.
However, the Nasa craft will also collect 30 to 40 rock samples and seal them in titanium tubes on the Martian surface for future retrieval.
Deputy project scientist Dr Ken Williford spoke at the Goldschmidt Conference geochemistry meeting in Paris, France, and said: "Mars 2020 represents a crucial first step towards a possible Mars sample return.
"Our objective is to collect a diverse set of samples from our landing site with the best potential to preserve records of the evolution of Mars, including the presence of life if it was there."