* Astronomy

Deep microbes live long and slow

A diverse range of life forms exists deep below Earth's surface, scientists have concluded, but they live at an incredibly slow pace.
Long-lived bacteria, reproducing only once every 10,000 years, have been found in rocks 2.5km (1.5 miles) below the ocean floor that are as much as 100 million years old.
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Life found deep under the sea

For the first time, scientists have discovered microbes living deep inside Earth's oceanic crust - the dark volcanic rock at the bottom of the sea. This crust is several kilometres thick and covers 60% of the planet's surface, making it the largest habitat on Earth.
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  Impacts Could be Boon for Subterranean Life

An incoming asteroid is trouble whether you're a dinosaur or a Bruce Willis fan. But microbes living deep underground may actually welcome the news, according to a recent study of an ancient impact in the Chesapeake Bay. A biological census of the subsurface life forms suggests that impacts create new niches for these deep dwellers to spread into.
In the last couple of decades, biologists have come to realise that the biosphere doesn't stop at the surface. A large fraction of the Earth's biomass is lurking down below. Several drilling projects have brought up evidence of hearty little microbes thriving in deep rock sediments. Some eat organic scraps that seep down from our world, while others derive energy through chemical reactions with iron and sulfur.
Although it's hardly paradise, this netherworld has one thing going for it: it's fairly peaceful. There's no night or day, no winter or summer. No global warming or ice ages to worry about. Only the occasional earthquake or giant space rock is really going to shake things up.
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Diamonds Show Depth of Earth's Carbon Cycle

Scientists have speculated for some time that the Earth's carbon cycle extends deep into the planet's interior, but until now there has been no direct evidence. The mantle - Earth's thickest layer - is largely inaccessible. A team of researchers analysed diamonds that originated from the lower mantle at depths of 700 kilometres or more, and erupted to the surface in volcanic rocks called kimberlites. The diamonds contain what are impurities to the gemologist, but are known as mineral inclusions to the geologist. Analysis shows compositions consistent with the mineralogy of oceanic crust. This finding is the first direct evidence that slabs of oceanic crust sank or subducted into the lower mantle and that material, including carbon, is cycled between Earth's surface and depths of hundreds of miles.
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