INTERSTELLAR PANSPERMIA HUNTERS

An excerpt from the latest (De)Extinction Club Newsletter: It’s tough times if you’re a crater hunter. The glory days are gone. On Earth at least. All the major impact sites that can be found have been found. All the big game are gone. Nothing but small fry left. Oh sure, there’s plenty of those around. […]

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Oil reservoirs, formed over millions of years as carbon-rich sediments are compressed and cooked, are scattered like islands across Earth’s subsurface. Like other deep biosphere habitats, we know they harbor life, but we aren’t really sure how or when life got there.

“There’s a hypothesis that these bacteria were buried, then continued to live on in complete isolation,” study author Olga Zhaxybayeva told me.

To test that hypothesis, the team of researchers, hailing from Dartmouth College, the University of Alberta, and the University of Oslo, analyzed 11 genomes of the heat-loving bacterium Thermotoga. The bacteria was taken from oil reservoirs in the North Sea and Japan, and marine sites near the Kuril Islands, Italy and the Azores. They compared their results with publicly available Thermotoga genomes from North America and Australia.

Their analysis revealed a complex evolutionary history between the different genomes, suggesting rampant gene swapping across far-flung communities. And since the oil beds themselves are ancient, this genetic exchange has probably been going on for millions of years.

How microbes half a world apart actually exchange genetic material isn’t totally clear. Some bacteria are genetic scavengers, sucking up stray DNA willy-nilly. Others use microscopic tubes to pass genes back and forth in a weird bacterial version of sex. And viruses—which cut and paste DNA among surface-dwellers’ genomes all the time—might also shape the genetic landscape of the deep biosphere.

“The answer is probably that it happens in a variety of ways,” Zhaxybayeva told me. “But it’s really surprising to see how much it’s happening. It’s clear that these organisms are not nearly as isolated as we once thought.”

The author’s findings may also shed light on the nature of life on early Earth. Zhaxybayeva, who has been mapping Thermotoga’s lineage for over a decade, says the organism has deep roots in the tree of life.

“This lineage is perhaps one of the most ancient that exists today,” Zhaxybayeva said. “The fact that it’s anaerobic, and likes hot environments, fits with our understanding of where life on Earth first evolved.”

Thermotoga’s penchant for gene swapping may indicate a once-widespread adaptation for life in hydrothermal vents, where high heat and acid have no trouble shredding DNA apart.

“As temperatures rise, organisms accrue more DNA damage. One way to potentially repair their genome is to actually recombine it— to patch their genomes with similar DNA,” Zhaxybayeva said.

Top-notch DNA repair machinery may be life’s most precious survival tool. Who knows, maybe it’s Earth’s most ardent gene-swappers that could actually survive the long, dark, radiation-filled trip to another world.

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The Dark Extropian Report: PANSPERMIA SPECIAL EDITION

fuckyeahdarkextropian:

Welcome to a Special Edition of The Dark Extropian Report. It’s been a bumper few weeks, months and years even in the world of astrobiology, and in particular in the area related to the theory of Panspermia – the idea that life came riding in on an asteroid or comet to our planet. This is one of the very core ideas of Dark Extropianism; that we are inextricably bound to the cosmos, on a grand scale that at the very least is inter-planetary. That our fate lies there as much as our origins do. That we are more than just star dust, but part of a living system that spans billions of years, who’s distance is measured by the speed of light. That ecology is something that spans the galaxy. That we are not meant to stay here, that our destiny lies amongst the stars.

The Dark Extropian Report: PANSPERMIA SPECIAL EDITION

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DNA Can Survive Sub-Orbital Spaceflight And Atmospheric Reentry

coldalbion:

//www.youtube-nocookie.com/embed/g5ujsROMsAU

zerosociety m1k3y

DEATH DEALER, LIFE GIVER… ASTEROIDS!!!

DNA Can Survive Sub-Orbital Spaceflight And Atmospheric Reentry

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So far, Steele has found no hint of martian biology—just trace amounts of organic molecules associated with volcanic processes. But he has found plenty of Earth bugs in the cracks—something that he takes as a good sign. “It’s a very habitable rock,” he says. “All it needs is a little warmth.”

A castaway from ancient Mars
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Thomas Gold, a professor of astronomy, suggested in 1960 the hypothesis of “Cosmic Garbage”, that life on Earth might have originated from a pile of waste products accidentally dumped on Earth long ago by extraterrestrial beings

Accidental panspermia
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Perhaps a safer way for seed to spread would be for whole rocks to travel other worlds. Previous research has showed that, theoretically, a massive meteorite impact could blast up and scatter tonnes of rock across the solar system.

In their recent paper, Hara and colleagues considered one of the biggest meteorite hits known in Earth’s history: the Chicxulub impact 65 million years ago, usually blamed for killing off the dinosaurs. The 10-kilometre-wide asteroid weighed well over a trillion tonnes, and could have excavated as much mass from the surface of the Earth.

The team calculated how much of that stuff could have ended up on the bodies in the solar system thought most likely to be hospitable to life: Saturn’s moon Enceladus and Jupiter’s moon Europa, both of which are thought to have subsurface oceans of liquid water.

Under certain conditions, as many as 300 million individual rocks could have ended up on Europa, and 500 on Enceladus, they calculated. Even more could have ended up on the moon and Mars. The team write:

“Although it is uncertain how rocks enter the presumed sea under the surface, for example, of Enceladus and Europa, the probability may be high that microorganisms transferred from Earth would be adapted and grow there.”

A handful of rocks could even have made it to planets around other stars. Once such could be Gliese 581, a red dwarf 20 light years away with a super-Earth orbiting at the outer edge of its habitable zone, where water could be liquid. Hana and colleagues calculated that about 1000 rocks from the Chicxulub impact could have reached that far in about a million years, meaning any life that made it would have had 64 million years to develop – or die off.

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