Imagine being able to do a complete reset of planet Earth. To be able to erase all life on Earth and start over. It seems a bit morbid idea, but for three scientists from the universities of Oxford and Harvard it was simply an exercise in calculation. Which a few years ago gave a rather beautiful and encouraging answer. For the Earth, I mean. But I found it an important message for us too, suggestive in this year that has just begun.
What would it take to completely sterilize our planet, then? Researchers they discovered thatDespite everything the universe could throw at us, life on Earth would be able to survive just about anything. This makes us understand how life is more tenacious than we think.
The Earth still has a long way to go
To arrive at their conclusions, the scientists observed the most "highlander" beings ever. No, it's not us. They are tardigrades. Yes sir. They found that tardigrades, also known as water bears, are the hardiest creatures in existence. These microscopic beings are able to survive extreme temperatures, radiation, starvation for decades and even to the vacuum of space. After analyzing several factors, the scientists concluded that the only way to eliminate them (and thus kill "the last survivors" and life on Earth) would be to boil the entire ocean.
That's not a very likely event: it would require a giant asteroid (almost another planet), a supernova or an ultra-powerful gamma-ray burst. Stuff too rare or too distant in time to worry the tardigrades, who on the other hand already don't give a damn about it. These little villains are rock hard and seem to have virtually eternal life.
Of course, life on Earth will have to end sooner or later. Here's when: day more, day less
Life on Earth, however, has its deadline despite all its ability to resist. And this deadline essentially depends on the sun, which supplies the energy needed to sustain it. Sooner or later the time will come when its light will no longer be sufficient to support life on Earth, but there are still about 7,6 billion years left. Quite a lot, if you consider that our planet has been around for about 3,8 billion years.
And if you think that it took just 600 million years to go from worms to Frank Zappa, you will understand that the planet is young and still has so much potential. Humans are just a small piece of this huge puzzle.
And now, we come to the moral
I lied to you at the beginning of this post. The study by Oxford and Harvard scientists has not just one message for us, but several. First of all: think of the infinite variety of life forms that could exist in space on other planets and moons, even in our own solar system. Tardigrades, also known as "little Terminators" for their uncanny ability to survive extreme conditions, are just one example of how resilient life can be. There may be even more hardy species that thrive in the deep soils of Mars or in the volcanic oceans of Europe o Enceladus.
Dr Rafael Alves Batista, co-author of the study, summed it up very pragmatically:
If tardigrades are the hardiest species on Earth, who knows what else is out there.
Finally, the part of Caesar. What we men can do. Of course, we shouldn't take our survival for granted, because it isn't. Humans need to do their part to protect the Earth and prepare for climate change, as well as keep an eye on climate change asteroids that could threaten our planet. But if tardigrades teach us anything, it's that life is surprisingly resilient and could thrive for a long time no matter what. Carry the message with you into the new year, and hold on!