the turning point in the history of planetary exploration came in 1976. Two Viking crafts, launched by the us, tested the soil on Mars for microorganisms. Unfortunately, they found none. Scientists concluded that life did not exist on Mars, or at least on the parts of the planet where the spacecrafts had landed. But now, a team of scientists at the Scripps Institution of Oceanography, California, usa , have claimed that the spacecraft could have missed out on signs of life on the Martian surface.

The Martian soil collected by the Viking missions was analysed inside the spacecraft in an automated fashion. The soil was heated and the gases were analysed by