Life from outer space may well be reseeding itself
There are certain phrases forbidden to science journalists. Contained in a large book at science journalism headquarters, they’re written in the blood of perpetrators. And there are no words inked more often than “aliens” and “extraterrestrials”.
If they’re contained in a headline, it is even worse. If there is an exclamation mark anywhere in sight, you might just as well hand in your science journalist card.
Because it is never true. As a colleague often reminds me: “Extraordinary claims require extraordinary proof.”
Claiming that aliens exist requires some pretty remarkable intergalactic proof. That said, there are exceptions to the “no aliens” rule and the latest research published in the Proceedings of the National Academy of Sciences is worth skirting that dangerous line.
Researchers from Harvard University, using computer algorithms modelling the spread of life in planetary systems, have shown that the spread of life is more likely on another planetary system than it is in our own. Important note to appease my science journalism overlords: they’re not saying they found it, but that it is more likely to have spread in that system.
Earlier in 2017, Nasa announced the discovery of a remarkable planetary system: seven planets orbiting a cool parent star about 40 light years away, which in interstellar terms is a walk to the corner store.
But life needs more than a planet to survive. Our blue and green globe has a cushioning atmosphere of nitrogen, with a soupçon of oxygen so we can breathe, and a magnetic core creating a field that protects us from cosmic radiation. It is also situated in an area called the “Goldilocks zone”, the perfect distance from the sun, so that it is neither too hot nor too cold and can have liquid water. If Earth were closer to the sun, water would evaporate; if it were further away, water would freeze. We have carbon-based life on Earth because we have water.
All the planets discovered in the Trappist-1 system could have liquid water. While the planet hunters were vindicated to discover a cornucopia of rocky, Earth-sized planets, those dedicated extraterrestrial life-seekers are apoplectic with excitement.
But, the alien hunting theory goes, there needs to be something that sparked the life.
This is where interplanetary panspermia comes in. Panspermia is a theory that maintains that the Universe is full of life and it is seeded around the cosmos by meteors, asteroids, and comets — not to mention spacecraft ( when we finally leave our little corner) of the Universe.
This is one of the ideas about how Earth got life. But, according to this research, the Trappist-1 system is “orders of magnitude” more likely to have been at the mercy of seeded life via interplanetary panspermia.
COMPUTER ALGORITHMS SHOW … THE SPREAD OF LIFE IS MORE LIKELY ON ANOTHER PLANETARY SYSTEM THAN IT IS IN OUR OWN
In their paper, Manasvi Lingam and Abraham Loeb, researchers at Harvard University and the Harvard-Smithsonian Center for Astrophysics in the US, respectively, write: “Our paper addresses the possibility that life on one of these planets can spread to others through the transfer of rocky material. We conclude this process has a high probability of being operational, implying that this planetary system may possess multiple life-bearing planets. Thus, our work has profound theoretical and observational consequences for future studies of the Trappist-1 system and the likelihood of life in our galaxy.”
There is another phrase that is verboten — “it’s worthy of science fiction”.
But this isn’t so much the stuff of science fiction, it is rather the dream of science fiction — life seeding and reseeding itself through an abacus of planets.