Earth is a very special place. Over billions of years, life has evolved to take on many different forms on our planet, withstanding some of the harshest conditions imaginable. But despite the ability of life to “find a way,” some tiny corners of our planet remain entirely inhospitable to life in any form, and a new research paper examines one such area: the hyperacid ponds of the Dallol geothermal field in Ethiopia.
The region is dotted with steamy ponds that contain highly acidic water. The saline-rich pools appear devoid of life at first glance, but scientists wanted to know if any type of microbial life managed to adapt to the extreme conditions.
The paper, which was published in Nature Ecology & Evolution, reveals that the ponds are simply too insane for even the most salt-loving microorganisms to call them home. The researchers expanded on previous studies and confirmed the absence of life using scanning electron microscopes, X-ray spectroscopy, and advanced breakdowns of the chemicals present in the pools.
Over the course of human history, we’ve assumed a lot of things about where life can and can’t exist. A lot of those assumptions turned out to be false. For instance, it was thought that life simply couldn’t exist at the bottom of the oceans due to a total lack of sunlight. That turned out to be completely untrue, and today we know there is a wide variety of organisms that live even in the most extreme undersea climates.
What’s perhaps even more interesting is that life is indeed present in the areas surrounding the pools. It’s microscopic, so you’d never know it’s there without the help of high-powered microscopes, but those tiny organisms steer clear of the ponds themselves.
“What does exist is a great diversity of halophilic archaea (a type of primitive salt-loving microorganism) in the desert and the saline canyons around the hydrothermal site, but neither is found in the hyperacid and hypersaline pools themselves, nor in the so-called Black and Yellow lakes of Dallol, where magnesium abounds,” Lopez Garcia, co-author of the paper, said in a statement. “And all this despite the fact that microbial dispersion in this area, due to the wind and to human visitors, is intense.”
Understanding the limits of life here on Earth can play a role in the never-ending search for life beyond our planet. Studies like this one tell us a lot about Earth, but might tell us even more about other worlds.