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Panspermia is a hypothesis that suggests life isn’t an Earth-only affair. The seeds of life may have spread throughout the Solar System and beyond via chunks of rock or comets, encountering planetary bodies, transporting spores or bacteria to other worlds. In short, we could be living in a cosmic ecosystem linked through simple interplanetary vagabond bacteria.
However, panspermia remains in the realms of speculation as we haven’t found any examples of extraterrestrial life (so far), let alone the possibility that life may be roaming freely through the vacuum of space. But panspermia as a life-spreading mechanism remains a possibility.
Now, famous physicist and futurist Freeman Dyson has come forward with an idea about what we should be looking for during the search for extraterrestrial life. Dyson believes the search for ET is flawed, as we are looking for what we deem to be probable lifeforms; perhaps we should be looking for detectable lifeforms.
And what’s one of the most detectable forms of life we know of? Flowers. What’s more, these flowers may have spread as far afield as the Kuiper belt and the Oort cloud…
“I would say the strategy in looking for life in the universe [should be] to look for what’s detectable, not what’s probable,” Freeman Dyson said on Saturday at a conference in Cambridge, Massachusetts.
“We have a tendency among the theorists in this field to guess what’s probable. In fact our guesses are likely to be wrong,” Dyson said. “We never had as much imagination as nature.”
We only have nature on Earth to learn from; this is the only life we know. There’s a certain set of rules life on Earth lives by (i.e. life exists here because it has evolved to adapt to temperatures, pressures and availability of sustenance), there’s a possibility that extreme forms of life could exist on other planets, but until we find this life, we don’t know what rules that life lives by. So scientists will logically look for probable forms of life.
However, Dyson points out that we should look for the most detectable forms of life. And one such example is the flower.
The Arctic Poppy (pictured top) is a flower that forms a parabolic shape. This shape maximizes the light that reflects off the inside of the petals so the interior of the plant can utilize solar energy. In the Arctic, often light is at a premium, so the flower has adapted to make full use of the Sun it can receive. From a distance, these mini solar collectors reflect a lot of light, and they should create a good indicator that plant life is thriving.
Now if we think about the icy Jovian moon Europa, it is thought to contain a liquid water ocean beneath a thick crust of ice and astrobiologists are very keen to send a mission to probe this potential life-harbouring habitat. Unfortunately, it might be hard for any robotic submersible to drop into the depths of this sub-surface sea as the ice could be up to 100 km thick in places.
So Dyson suggests that perhaps we should send an orbiter to Europa, not to look for an indication of life in the sub-surface ocean, but to look for more detectable signs of life, like flowers on the surface of the icy planet. After all, many types of plants grow in extremely cold locations on Earth, perhaps extreme plants thrive on Europa’s surface too?
“You can imagine once you have flowers that get nourished from below, they could evolve in the direction of being independent,” said Dyson.
He points out that once these plants become established on a body such as Europa, there’s the possibility that the seeds of these plants become distributed around the Solar System. If we ignore the fact that “life as we know it” requires a certain amount of solar energy to survive (at an orbital distance that is neither too close or too far from the Sun; otherwise known as the “Goldilocks Zone”), plant life that can survive in astonishingly cold temperatures may have adapted to live as far afield as the Kuiper Belt (near the orbit of Pluto), or beyond.
These are fair points, but I’d be cautious about trying to imagine the unimaginable. Although we need to keep an open mind as to what extraterrestrial life might look like, and optimize our search for detectable signs of life, we need to remember that the only form of life we know of and can study is here on Earth, and it remains a good starting point when looking for life on other planets.
Still, the thought of Arctic Poppies growing on Europa is an interesting idea, as it is possible, if panspermia is proven, that the Europa Arctic Poppies could be a descendent of their terrestrial counterparts…
Original source: New Scientist