Artist’s impression of potential living exoplanets. Credit: NASA / JPL-Caltech / R. Hurt (SSC-Caltech)
A study by the University of Southampton offers a new perspective on why our planet has been living for billions of years – concluding that it is almost certainly the result of fortune. The research suggests that this may expand the strange notions of finding life on the name ‘Earth-twin’ in the Universe.
The research, published in the journal Nature Land Communications and the Environment, including making the first simulation of climate evolution on thousands of randomly generated planets.
Geological data show that the Earth’s climate has remained constant for over three billion years. However, it has been delicately balanced, with the ability to rapidly decompose to deep frozen or unbearably hot conditions causing sterility throughout the planet.
Professor Toby Tyrrell, an expert in Earth System Science at the University of Southampton, explains: “A stable and stable climate on Earth is remarkable. Our neighbors, Mars and Venus, do not have arable temperatures, even if Mars once existed. Not only does the Earth have an arable temperature today, but it has maintained this all the time over three or four billion years – a remarkable period of geology. ”
Many events can threaten the continued stability of a planet – asteroid impacts, solar flares and major geological events, such as the explosion of supervolcanoes. In fact, an asteroid that hit the Earth 66 million years ago caused more than 75 percent of all species to become extinct, killing the dinosaurs along with many other species.
Previous computer modeling work on the potential of the Earth has included the modeling of one planet: Earth. However, inspired by discoveries on exoplanets (the ones outside our solar system) that reveal billions of Earth-like planets in our galaxy alone, a Southampton scientist took a new approach -new for studying a big question: what made the Earth stay. sustain life so long?
To study this, Professor Tyrrell harnessed the power of the University of Southampton’s supercomputing facility to run simulations looking at how 100,000 different planets randomly responded to climate change events over three billion years, until they reached a place where they always lost their way. Each planet was simulated 100 times, with different random events each time.
Cliu: Kate Davis
After getting a huge collection of results, he then looked to see if the sustainability of living was limited to just a few planets that were always capable of sustaining life for three billion years, or instead spread around on many different planets, each of which just sometimes inhabits a residence for this time.
The results of the imitation were very clear. Most of those planets that sustain life for the three billion years were only a probability, not a certainty, of living. There were many examples of planets that would usually fail in the symbols and just sometimes inhabit them. Out of a total population of 100,000 planets, nine percent (8,700) were successful at least once – of these, almost all (about 8,000) were successful less than 50 times out of 100 and the majority (approximately 4,500) were successful less than 10 times out of 100.
The findings of the study suggest that chance is a key factor in determining whether planets, like Earth, can continue to cultivate life over billions of years. Dr Tyrrell concludes: “We can now understand that the Earth remained fit for life for so long because of, at least in part, fortune. For example, if a slightly larger asteroid had hit the Earth, or done so at a different time, the Earth might have lost everything.
“To put it another way, if an intelligent observer had been present on Earth early as life first evolved, and was able to find out what the opportunities would be. planet to live for the next several billion years, the calculations may have revealed very poor odds. ”
With these bizarre observations, the study argues that Earth-like planets should be found elsewhere in the Universe that were originally intended but became, as a result of probable events, too hot. or too cold and so lost their lives on them. As methods of studying exoplanets become better, and as they are first seen as a ‘pair of Earths’, most of them are likely to become unstable.
Fact: “Chance played a part in determining whether the Earth was inhabited” by Toby Tyrrell, 11 December 2020, Land & Environment Communications.
DOI: 10.1038 / s43247-020-00057-8