File this under: What don’t we know?
We just discovered slice “2″ is alive. |1 – Continental crust | 2 -Oceanic crust | 3 – Upper Mantle | 4 – Lower Mantle | 5 – Outer Core | 6 – Inner Core | Image Credit: Dake
You might have thought that photosynthetic life forms had the Earth covered, but according to some researchers the largest ecosystem on Earth was just discovered and announced last Thursday, and it’s powered by hydrogen, not photosynthesis.
The Oceanic Crust is the rocky hard part under the mud that lies under the ocean. It covers 60% of the planet and it’s 10km thick. (The oceans themselves are a paltry 4km deep on average.) We’ve known for years that the isolated hot springs in trenches held life. But who thought that all the hundreds of thousands of square kilometers of basalt rock in between had its own life cycle? Last week a group from the Center for Geomicrobiology at Aarhus University, Denmark announced that they had drilled through crust that was 2.5km underwater and 55 km away from anything that mattered. They found life in the basalt.
“We’re providing the first direct evidence of life [...]
File this under: “How little we know.”
The upper troposphere is apparently teeming with particles of bacteria and fungi, surprising researchers.* Proving that life is tenacious and that microbes can survive just about anywhere, a team at Georgia Institute of Technology have discovered that quite a bit of what we assumed was dust and sea-salt may be bacteria aloft. Some of the little critters made it as high as the upper troposphere which is 10km up (where commercial flights cruise). No one is quite sure if the microbes “live” up there, or were just visiting.
The study showed that viable bacterial cells represented, on average, around 20 percent of the total particles detected in the size range of 0.25 to 1 microns in diameter. By at least one order of magnitude, bacteria outnumbered fungi in the samples, and the researchers detected 17 different bacteria taxa – including some that are capable of metabolizing the carbon compounds that are ubiquitous in the atmosphere – such as oxalic acid.
The bacteria were probably tossed up there by wind and waves:
When the air masses studied originated over the ocean, the sampling found mostly marine bacteria. Air masses that originated over land had [...]