They Didn’t Find Life in a Hopeless Place

Astrobiology and the "Search for Life" is a neat field. I worked with scientists whose extremophile research took them to volcanoes, deep underground and beyond. Some scientists suggest that when we searched for signs of life in the solar system years ago, our parameters of "life" were too narrow. Extremophile research broadens the parameters in the search for life. And the science is fascinating. We were taught in grade school that people breathe in O2 and exhale CO2. Plants do the opposite. But some extremophiles live off of methane, as an example. Extremophiles don't fit the mold of what we thought we knew. The search continues.

But the microbes that live in deep-sea thermal vents have lived there since that became the typical survivable environment on earth in which they were forced to adapt, and there were no other nutrient-rich alternatives, not that they migrated to such an environment after somehow 'choosing' to leave more life-friendly environments. Somewhat similarly, as the once warm antarctic environs began to freeze, microbial life was forced to adapt, such as those found at the bottom of two recently discovered sunless, low oxygen subglacial lakes in Antarctica. Comparatively, the Danakil Depression is a recent geological feature--there is no biological-survival impetus for any microbe to abandon nearby, more hospitable living conditions to adapt to it. Granted, if the Danakil Depression had harbored some sort of microbial life and we discovered it, it would be remarkable, but there is no fundamental reason for life to have ever needed to adapt to it.

Danakil evolved in nature. Part of it is Acid Rock Drainage (ARD) wherein pyrites and sulphides (fuels) start cooking when they come into contact with water and oxygen. The result is acid that leaches in to the ground. ARD can occur when mining companies dig dirt in millions and billions of cu m and leave sites without properly capping the dumps post mining activity. There are several thousands abandoned mines that drain acid into the ground everywhere. ARD Is like nuclear reaction. Once started, very hard to contain. Mining companies do this because active mining lasts for several decades and during early stages of stripping overburden there is no revenue to prepare dumps properly. When mining finishes, the relinquishment occurs only after 60 years or so. No government system exists to monitor companies for that long a time. There are several man made Danakils each year!

Ethiopia’s Danakil Depression sounds fascinating, if inhospitable. Although the scientists did not find any 'life' as we know it, I increasingly believe that most of us humans have a very limited definition of what we consider to be alive.

“If the conditions are permissive for life as we know it on Earth, they should be permissive for life as we don’t know it on another planet.” well, maybe. the logical difficulty is that conditions that permit life to exist are not necessarily the same as the conditions that are necessary for life to form in the first place. evolution and abiogenesis are two entirely different problems. the mention of magnesium salts versus potassium salts is a useful illustration. do their contrasting effects depend on a fundamental chemical distinction, or do they depend on the fact that abiogenesis formed primitive life of a kind that excluded one or the other from a useful role? aside from the very amusing fact that a social animal species seeks life as proof that "we are not alone," it's important to understand whether our specific carbon based biochemistry is unique, or other forms (requiring magnesium, shunning potassium) are possible. it all goes back to the total domain of possible forms of abiogenesis; that is the only denominator in valid astrophysical theories of life.