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Journalism of Courage
Our neighbour,or neighbourhood,has tantalised and beckoned us as long as weve been neighbours. In an extension of this very human predilection,there never was anything remotely other-worldly about our attention to our planets neighbourhood. How fascinatedly and passionately have we been looking for evidence of life on Mars,and again by extension,for that necessary precondition to life water?
NASAs Mars Reconnaissance Orbiter has now revealed what could be evidence of flowing water on Mars. The observations dont prove the existence of flowing water,but offer the best explanation of the tendrils seen between rocky outcrops on Martian hillsides facing the equator and the summer sun. These finger-like structures,a few metres wide and probably made of thawing mud,extend down the slopes from late spring through summer,fading in winter and reappearing the following spring. Thats why,the interpretation of the images hints at flowing,liquid
water a possibility more significant for life on Mars than that opened up by the discovery of rocks rich in carbonate minerals a few years ago which had suggested the presence,once,of perhaps a large amount of water on Mars.
For,evidence of flowing water would significantly enhance the chances of finding life,such as hardy microbes that could survive in the summer meltwater. If this is indeed water and flowing,it will be briny,since saltiness lowers the temperature at which water freezes,opening up the possibility of water on Mars as salty as our oceans but not fresh water. Published in Science on Thursday,the argument for briny flows seems stronger than alternatives. In any case,in a tiny drop,seen or unseen,could lie another giant leap for humankind. Earths neighbour Mars has reaffirmed its enticement for human exploration.
