Jonathan Clarke has just returned from another mission to simulate life on Mars, this time from Devon Island in the Canadian Arctic.
If there ever was life on Mars it may still be there, writes Malcolm Walter. And if we can demonstrate an independent origin of life, the consequences will be profound.
India's mission to Mars will search for methane and could reveal an important aspect about the history of water on the red planet, writes Malcolm Walter.
I have been searching for evidence of extra-terrestrial life since the 1980s. I believe that we will probably find it, writes Malcolm Walter.