Mars

Is there archaeology on Mars?

Mars has long been a source of fascination for those who seek life off the Earth. Early astronomers noted seasonal changes: the normally red surface of the planet could be seen to develop darker, greenish patches during the Martian ‘summer’, as the polar ice caps melt. They darken annually (in Martian terms) and always in the same patterns; in some years, they are more intense than others. This suggested the existence of plant growth to many astronomers before satellite exploration would suggest otherwise. The twenty-two close-up photographs sent back by Mariner 4 in July 1965 showed a cratered surface with a thin atmosphere (largely composed of carbon dioxide at a pressure of 5 to 10 mbar). Later missions (especially Mariner 9 in 1971, Vikings 1 and 2 in 1976, Mars Global Surveyor since 1997 and Mars Pathfinder in 1997) have shown a dead planet without liquid water, suffering freezing temperatures and swept by violent winds. Nevertheless, they have also shown that conditions were once very different, with evidence for plate tectonics (no longer functioning), river channels, ocean shorelines and an atmosphere formerly richer in oxygen. This has led some researchers to suggest that not only life, but also an advanced civilisation may once have existed on Mars.

This page was last updated on 23 July 2007
Written by Keith Fitzpatrick-Matthews and James Doeser