Science

Earth's hardiest species likely to survive 'until the Sun dies'

Earth's hardiest species likely to survive 'until the Sun dies'

Most of the studies conducted by researchers from Oxford and Harvard University came to the conclusion that the only thing to wipe out life on earth would be if the oceans boiled. We don't yet know if any of these host life - and we don't know how life begins. The phylum has existed for at least 520 million years, through multiple mass extinctions. It's always been thought that an asteroid impact ended the dinosaurs. "Subtle changes in our environment impact us dramatically", Dr. Batista said.

"There is a third scenario, where life continues around geothermal vents on a rogue planet until capture by a new host system, or the source of heat is extinguished... life could [endure] on a rogue planet long enough for it to be recaptured [into another solar system]."

But unlike the cockroach, the Tardigrade will survive until the sun dies or an asteroid impact boils off our oceans, according to a new Oxford Uni study.

Micro-animals are creatures which are only visible under a microscope.

Loeb's team found that there are only 19 asteroids in the solar system sufficiently massive enough to eradicate water bears, and none are on a collision course with Earth.

Tardigrades are known to survive incredible conditions. No problem. Temperatures plummeting to -272° Celsius or skyrocketing to 150°? Specimens have been observed to exist without food or water for more than 30 years. "Organisms with similar tolerances to radiation and temperature as tardigrades could survive long term below the surface in these conditions".

Those that can survive the loss of light will be so hard to destroy they could live on other planets, the report said. "Radiation can cause the depletion of the ozone layer, removing the shield that protects us from cosmic radiation".




Tardigrades: the last survivors?

Normal natural disasters that are fatal for humans - volcanoes, tsunamis, and the like - weren't even considered in the study: This is the mind-blowing endurance of the tardigrade, here; the suggestion that those events could be hazardous is nearly insulting. We therefore have to consider the astrophysical events that could provide such an enormous amount of energy.

"To our surprise we found that although nearby supernovae or large asteroid impacts would be catastrophic for people, tardigrades could be unaffected". Of these, asteroids are the most familiar.

If a monster space rock crashes into our planet or radiation from an exploding star boils our oceans, humans and most other life forms will disappear. This turns out to be approximately once every 10 years - far longer than the life of the universe. Since the nearest star is four light-years from our sun, that's not going to happen. The central bulge is more densely populated than our neighbourhood.

Gamma-ray bursts, one of the brightest phenomena in outer space, are also too distant to pose a threat (they'd have to be 40 light-years away or less).

The only event that would kill even the tardigrades, is when the Sun eventually burns out. Again, the rate at which this would occur is sufficiently low that very few planets would ever be sterilised by a gamma-ray burst.

Researchers say there is a chance that a supernova, an exploding star, could be big enough to wipe out life on Earth within our sun's lifetime and this event is negligible. One final, incredibly unlikely possibility is that a passing star could kick a planet out of its orbit.