Friday, December 08, 2006
Does Water on Mars Mean Life on Mars?
The news is currently full of a report from NASA concerning before and after photographs of Mars that show a new surface streak that some scientists interpret as being caused by a flow of liquid water over the martian surface. cf. The Daily Telegraph, 'Signs of Water on Mars'; Guardian, 'Water discovery boosts hopes of life on Mars'
Other scientists interpret the liquid is liquid CO2
The news is also full of the question of life on Mars, and of the common assumption that the presence of water makes the discovery of life considerably more likely.
Well, water on Mars makes life on Mars more likely than it would be without water; but that is still not at all likely really. Mars might harbour bacterial life as a consequence of cross-contamination from earth - but current evidence would indicate that this is the most we would expect to find. Mars plus Water certainly does not equal Life! To think that it did would be a bit like saying:
'We have discovered mineral deposits, therefore we are likely to discover cars. After all, mineral deposits are a necessary condition of the existence of cars...'!
See also: Hugh Ross, 'Water on Mars: What Does it Mean?'
Other scientists interpret the liquid is liquid CO2
The news is also full of the question of life on Mars, and of the common assumption that the presence of water makes the discovery of life considerably more likely.
Well, water on Mars makes life on Mars more likely than it would be without water; but that is still not at all likely really. Mars might harbour bacterial life as a consequence of cross-contamination from earth - but current evidence would indicate that this is the most we would expect to find. Mars plus Water certainly does not equal Life! To think that it did would be a bit like saying:
'We have discovered mineral deposits, therefore we are likely to discover cars. After all, mineral deposits are a necessary condition of the existence of cars...'!
See also: Hugh Ross, 'Water on Mars: What Does it Mean?'
