Hello, Hominids! Here we go with another ridiculous Sci Blog-in. It’s that time of the week once again (for reasons that remain mysterious) where we all talk about strange, complicated science stories, stare at gorgeous pictures of the Natural World, and recoil in horror at disgusting examples of animals that perfectly illustrate Nature’s marvelously weird sense of humor.
LOCATION, LOCATION, LOCATION. Charming terrestrial world, 4.45 billion y.o. Conveniently located in the life zone of a dependable main sequence G2V star. Quiet neighborhood, Great views. Nitrogen-Oxygen atmosphere, good ozone layer, strong magnetic field. 7 oceans 7 continents. Great place to raise your carbon based life forms! Pets OK.
This Earth of ours is just the perfect place for us to live, isn’t it? Its ozone layer protects us from UV radiation, the magnetic field keeps the solar wind from blowing the atmosphere away , there’s plenty of water and the temperatures are just about right. Of course, over the Earth’s 4.5 Billion year life it wasn’t always this way. At times the weather outside was downright lethally Frightful. The early earth was a brutal place, what with the Iron Catastrophe, the Late heavy Bombardment and the (likely)Giant Impact with a Mars-sized object that melted the entire planet and peeled off enough of its crust into orbit to form the Moon.
We think that conditions on Earth finally became stable enough to generate life at around 3.7 Billion years ago. The classic early Miller-Urey experiment that generated amino acids from simulated early earth conditions is just one possible pathway to living organisms. When Life did take hold on the early Earth, it gradually overspread the globe, changing both itself and the global environment in the process.
It’s remarkable to me just how deeply Earth’s living things have wandered to the furthest reaches of the world. Finding a huge, active community of microorganisms 7 miles down in the pitch dark, frigid, pressurized Mariana Trench really is remarkable though. An international team of researchers, led by Prof. Ronnie Glud from the Nordic Center for Earth Evolution at the University of Southern Denmark, developed special instrumentation for measuring bacterial activity in sediments and sent them to the ocean floor via unmanned submersible. Direct measurements are the only option, as any bacteria adapted to these depths die on their way to the surface. All over the world, in the strangest places, Life Goes On.