“able to support life“ ... as we know it.<p>The universe being so vast and so diverse, most life forms will probably escape our comprehension: completely different chemistry, environments (pressures, temperatures), time scales, state of matter (plasma based life forms?), or even energy based ones.<p>We are not even looking for such different life forms, since we have already concluded that:<p>- life must be water based<p>- life must be carbon based<p>- life must be based on dna (or simillar)<p>Which leads (given our limited knowledge of the chemistry of these substances) to the conclussion that life must be extremely similar to Earth's.<p>I see a lack of imagination here.