Scientists just discovered a new phylum of microbes in Earth's Critical Zone. The Critical Zone—also known as the planet's "living skin"—is responsible for processes like water filtration. The newly discovered bacteria may be able to metabolize pollutants in the future. We're walking around on living skin every day. Well... sort of. Earth's Critical Zone, often called its "living skin," is the near-surface environment that extends from the tops of trees down to about 700 feet into the soil. It's home to rocks, groundwater, and many, many organisms—and scientists just discovered a new resident. Published in the Proceedings of the National Academy of Sciences , the study finds a whole new phylum of microbes that may help purify water. A phylum is a level of classification below kingdom and above class. It's essentially a "major category" of living things that groups organisms together based on shared qualities. The newly-discovered phylum, CSP1-3, is just a small part of the diverse ecosystem that is the Critical Zone. Related Story Cyborg Bacteria Could Turn CO2 Into Fuel "This zone supports most life on the planet as it regulates essential processes like soil formation, water cycling, and…