Just because a planet has liquid, don't expect life there—at least according to a new study that delved into one of Earth's most toxic environments, CNN reports. Scientists took samples from the creepy, multicolored pools on a volcanic crater in Ethiopia, and found not one living thing. "After analysing many more samples than in previous works ... we have verified that there's no microbial life in these salty, hot and hyperacid pools or in the adjacent magnesium-rich brine lakes," says study author and biologist Purificación López García. If true, it means life endures in ice-cold tundras, parched deserts, and toxic vents on the ocean floor—but not in the boiling water of Dallol, a volcano in the northeast of the Erta Ale Range in Ethiopia. The question is why.
The answer, of course, is technical. Researchers say two physical chemical barriers prevent life there: lots of chatotropic magnesium salts along with a mix of hypersaline, hyperacid, and scorching-hot temperatures, per Phys.org. Now, caveats: Scientists did find single-celled organisms called Archaea in the less forbidding nearby ponds, and an earlier study found life even in extreme ones, but that might have been contamination from neighboring ponds. Bottom line? Think twice before saying that a watery—or once watery—planet has housed life. "There is this idea … that says any planet with liquid water on the surface is habitable," López García tells LiveScience. Water "might be a necessary condition, but it is far from sufficient." (See some other extreme locations in the world.)