At first glance, there doesn’t appear to be much happening in the mud buried 30 meters below the Pacific Ocean sea floor. But this ancient muck, which hasn’t had a fresh shot of food or sunlight since the days of the dinosaurs, still harbors life—if just barely. Scientists have discovered that deep-sea microbial communities, buried for 86 million years, are still consuming oxygen, albeit at extraordinarily low rates. These microorganisms eking out an existence in slow motion reveal just how little it takes to sustain life on our own planet, and potentially on others.
The limits of life are so much further beyond what we have imagined. Here we appear to see the lower energy limit for life below our current understanding. But we have to say now that we do not know where the lower limit is anymore. Learn more here, here, here or here.