These animals can survive until the end of the Earth, astrophysicists say
Late tardies are considered the most difficult animals on the planet. Some of these microscopic invertebrates repel temperatures below 272 degrees Celsius, a degree warmer than absolute zero.
Other species can withstand powerful radiation and space vacuum. In 2007, the European Space Agency sent 3,000 animals into Earth’s low orbit, where the tardigrades survived for 12 days outside the capsule.
For a group of theoretical physicists, tardigrades are perfect specimens to test the tenacity of life. “Life is pretty fragile if all your estimates are based on humans or dinosaurs,” said David Sloan, a theoretical cosmologist at the University of Oxford in Britain.
The tardigrade line is old. “The Tardigrade microfossils were reported from early Cambrian to lower Cretaceous, there are 520 to 100 million years,” said Ralph O.
Schill, tardigrade expert at the University of Stuttgart, Germany, who did not participate in this research. “They saw the dinosaurs come and go.”
Sloan, with his Oxford colleague Rafael Alves Batista and astrophysicist at Harvard University, Abraham Loeb, decided to try to rid the world of the tardigrades. In theory, at least, in a report published Friday in the journal Scientific Reports.
Through the powers of mathematical modeling, they launched three of the most devastating cosmic events of Earth’s killer, supernovae, and gamma-ray asteroids.
“These are the major forms of energy transfer for the planet,” Sloan said. Tardígrados continued Transport in the theory of 10 billion years of cataclysms. Until the sun has failed or enveloped the planet.
In choosing their apocalyptic poison, scientists first tried to sterilize the planet with radiation. In the laboratory, some species can survive late doses of radiation from 5,000 to 6,000 gray.
(“You would be very lucky to walk” a dose of 5 Gy, Sloan said.) But long before scientists make the ground with enough radiation to kill all the tardigrades, it is estimated that the radiation energy would boil the Means oceans. The critical point for tardigrades was then the evaporation of water on the planet.
For an asteroid deposited much energy in the ocean, a mass of at least 1.7 Quintile kilogram would be needed.
Of all the asteroids in the solar system, only 19 to conform to the law. (By comparison, the asteroid that killed the dinosaurs was six miles away, an asteroid called Vesta, which is a potential killer ocean has a diameter of 326 miles).
The chances of a massive collision are so small, according to scientists, the sun was going to die first.
Similarly, the closest stars that can explode in supernovae are very far to boil the oceans. The bursts of gamma rays were a bit more complicated: “I do not quite understand where they come from,” Sloan said, but not impossible to calculate.
And while blasts eliminate some parts of the atmosphere, killing animals like humans, small, enduring creatures in the ocean, crowded around hydrothermal vents, would be “adequately protected,” Sloan said.
But the mixing of all species later into an unfinished chimera was a fatal flaw in this argument, according to late expert William R. Miller. “I can not say anything physical,” he said, “but you can not say anything about animals.”