How fucking cool is that? The science nerd rejoices!
The hot soils of Erebus are dotted around its summit, most famously at a site called Tramway Ridge. Heat from the volcano melts the ice, creating small patches of hot, moist soil that become home to communities of mosses and microbes.
But here’s the thing. These patches are tiny islands of warmth in a sea of coldness. Although the soils themselves are hot—they can reach temperatures of 149°F—the air just above is not. Moreover, move a couple of feet away from the hot spot, and the soil temperature drops sharply. The acidity changes too. At the hot spot the soil is relatively neutral; a short distance away it’s harshly acidic. And lifeless: Cold, dry, and acid is unfriendly to life.
The presence of these islands raises intriguing questions. Which microbes live there, and where did they come from? Microbes can travel hundreds of miles on the wind. Did these blow in from the hot soils of volcanoes farther north? Or are the microbes on Erebus unique, and—this would be tremendously exciting—are they beings that have come up from deep within the Earth? The deep subsurface biosphere, where these organisms live in rocks far below the surface of the Earth, is one of the planet’s least known ecosystems. But it may be one of the largest—some estimates suggest that one-third of all bacteria on the planet might live there—and weirdest. Such microbes don’t make their living by drawing energy from the sun. Instead, they get energy from other sources, such as iron or hydrogen. This deep, dark ecosystem might also be among the Earth’s most primeval and could be home to life-forms that have long been charting a separate evolutionary course.