8 P52220RA Rethinking extremes 26. For millennia, microbes have searched for loopholes and experimented with novel molecular machines in an attempt to gain a foothold where others can’t. From backyard soils to seafloor methane seeps, these extremophiles eke out a living, revealing adaptations to the energy equation that may point us toward other organisms awaiting discovery in the headlights of a future robotic spacecraft. 27. Many of the most promising astrobiological targets in our solar system may well possess the baseline requirements for life such as liquid water and key elements, but net energy availability is an unknown. The lakes of Titan, Saturn’s largest moon, have plenty of organic fuel for the taking, but maintaining a viable microenvironment would likely be very difficult given the lack of an appropriate solvent at such frigid temperatures. The Martian subsurface, on the other hand, may lack easily obtainable energy sources, but with relatively few apparent hazards, a low-energy way of life could be feasible. 28. Researchers have yet to fully sample the diversity of bioenergetic regimes on Earth. With continued exploration of the seafloor or the planet’s deep interior, we find novel geochemical cocktails that demand microbial innovation. And so, back on the Atlantis, we load Jason with cleaned collection tubes and send our robotic emissary on yet another journey into the unknown, in search of new microbial responses to the extreme conditions of the deep. The Energy of Life by Jeffrey Marlow and Jan Amend, February 1, 2015. The Scientist Magazine. http://www.the-scientist.com/?articles.view/articleNo/41990/title/The-Energy-of-Life/