Argyre Planitia - the Argyre Basin, may have been something of a Martian Garden of Eden in the ancient Noachian epoch of the planet. With water from three large channels in the surrounding mountains flowing into a lake the size of the Mediterranean Sea, the interaction between the water, the rocks and ice deposits would have been excellent for the evolution of microbial life.

According to a new study by Alberto Fairen and his colleagues at Spain's Centre for Astrobiology: on ancient Mars, water was more plentiful in the Argyre Basin that at the Gale crater region where the Curiosity rover landed in 2012. The basin was probably formed during the Late Heavy Bombardment era (c. 4.1 - 3.8 billion years ago) when a very large meteor struck the region. The meteor most likely impacted in a layer of permafrost which melted and formed a giant lake which remained in a liquid state for millions of years.

From a geological point alone, the wide variety of features on the plains of the floor of the basin and in the surrounding rings of mountains, would make this an attractive proposition for a exploration site. Also the flat expanses on the plains would be ideal for landing, being at a low altitude which gives parachutes more time to slow the craft before landing rockets are fired.

It would be appropriate if at some point in the future the first manned mission to Mars touched down at the point where life began on Mars, although such a prospect raises once again the dilemma of manned exploration of Mars and other extraterrestrial locations - namely, the risk of contamination. Will it ever be safe to return rock and soil samples from Mars? Even one microbe of a type not even recognised as a living form by Terran biologists, could quite feasibly cause a mass extinction event on Earth, although it is unlikely.