People can live on every continent, but our planet really belongs to the microbes. Some even thrive in particularly pernicious environments, from deep-sea vents cooking at 251 degrees Fahrenheit to highly radioactive mine shafts.

These extremophiles can also be found in highly salty or highly acidic environments. But to date, microbes haven’t been unequivocally found inhabiting the combination — a simultaneously hot, hypersaline and hyper-acidic realm. If an organism could survive in such an unforgiving place, scientists would need to expand their search parameters for life in more unwelcoming corners of other worlds.

Attempting to ascertain life’s outer limits, scientists headed to Ethiopia’s Danakil Depression. A scorching, arid 155-mile-long lowland, it also contains the volcanic Dallol dome and its polychromatic geothermal field, which features some of the world’s saltiest, most acidic bodies of superheated water. The team scoured the landscape, looking for something that called one of these pools home.

But contrary to previous claims, no unambiguous evidence for any pioneering extremophiles was found. This was a disappointment — but also a crucial revelation.