<p><span style="font-family: georgia, 'times new roman', times, serif; font-size: 15px; line-height: 22px;">For those who hunt for life on other worlds, <a href="http://www.nytimes.com/2011/05/10/science/space/10water.html?_r=1&amp;ref=water">water</a> in its liquid form is perhaps the leading indicator. Life as we know it on Earth&nbsp;is based on water and carbon. And if organisms can prosper here in nasty environments — in geysers, in the depths of the sea, in toxic waste, in water that is too hot, too cold, too acidic or too alkaline — why could they not prosper out there?</span></p>