Panspermia Flower Power
Written by Ian O'Neill
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
Filed under: Extreme Life
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May 6th, 2009 at 5:31 am
Sorry, Mr. Dyson, I won't subscribe to the notion of flowers that far away from any kind of substantial light. I have no problems with fungi, bacteria, etc… you know, "things" that can get on with their lives without doing photosynthesis, but flowers?
I reckon the first extraterrestrial life we find will be microbes. They seem to be the most common life forms, even on Terra Firma, which is the home of a great variety of all sorts of conceivable multi-cellular creatures.
If somebody finds life within our solar system, I expect it'll be below the surface – not easy or obvious to see. I actually expect it to be there, but I'm not holding my breath for a discovery within my lifetime.
May 6th, 2009 at 6:42 am
If you want to see seasonal color change, look at Mars. If you want a planet with an atmosphere and temperatures that, in places and times, exceed 50 degrees F., look at Mars. If you want to see a planet that produces a real sign of life – look at Mars. It produces seasonal methane.
If you want to waste another generation of human fascination with the discovery of life off the Earth, then let's go to Europa!
May 6th, 2009 at 9:42 am
Dyson's idea doesn't make much sense to me. Any planet or moon that's going to be examined closely enough to detect microbes is unlikely to be able to hide lifeforms as large as flowers or something similar.
Europa's going to get at least one orbiter and one lander before it gets a mission capable of burrowing through miles of solid ice, and any lander mission will target cracks in the ice where it would be most likely to detect signs of life both macroscopic and microscopic. We're not likely to miss flowers when searching for bugs.
As for any flowers on Earth being descended from "space poppies?". Nice idea, but almost certainly impossible. Flowers are a fairly recent phenomenon, appearing about 150 million years ago, and while they are still trying to figure out their lineage (they don't exactly have a lot of fossils to work with) when studying their DNA there is no reason to believe that flowers had anything other than an entirely terrestrial origin.
May 6th, 2009 at 10:40 am
I should also add that while I think looking for flowers on Europa is a waste of time, I do think the various transpermia theories are plausible. ISRO recently discovered UV resistant bacteria in the stratosphere, so the major scientific objection to the Arrhenius version of the theory appears to be removed. The bottom line is, if any of the transpermia theories are true, then there really should be life on Mars, (or some fascinating or terrifying reason why Mars is now sterile). It is astonishing that some scientists would bypass Mars for Europa. Why can't Dr. Dyson look for his flowers on Mars?
May 6th, 2009 at 10:47 am
@ TD: You mention some positive factors for life to be possible on Mars. However, I'm sure that you're aware that 'seasonal methane' could also be accounted for by non-biotic processes. Definitely the methane question deserves more scrutiny before any conclusions as to its presence can be made. It would be fantastic if that methane signature is due primarily to biological processes.
May 6th, 2009 at 11:21 am
@ Jon H.: Yes….the seasonal methane could be due to some geologic process, just like the "Sinton bands" showing organics on Mars could be due to some peculiar minerals, just like Dolfus' polarization data showing seasonal size and shape change of small particles on Mars could be due to something other than life…just like the seasonal shade change could be due to seasonal movement of dust and not life….
Discovery of life off the Earth – even a lowly microbe on Mars, will be the greatest scientific discovery of all time. Confirmation of the spread of life via one of the methods of transpermia will even surpass that. But, with all these questions about Mars…no, let's go to Europa….that'll probably take another 20 or 30 years….very frustrating.
May 6th, 2009 at 11:58 am
But flowers are younger than the dinosaurs. They're not an ancient species at all. The idea that they should be anywhere than here on Earth as a result of convergent evolution is improbable in the extreme.
All due respect for Dyson, but he sounds like a loon whenever he spouts off about biology (cf. 'diamond dropping trees' to cure AGW). Sheeesssshh.
Bacteria, yes. Fungi, perhaps. Lichen, not very likely.
May 6th, 2009 at 3:14 pm
Ah yes, imagine our surprise to find swarms of vacuum sucking cryophilic pollenpacking levitating bomboids tending those pioneering poppies,,, you're getting sleepy…sleepy…la!
Phycoerythrin maybe, anthocyanins…not!
May 6th, 2009 at 3:19 pm
The problem with microbes is someone has to get down in the mud to find them.
Its hard to detect the things by remote sensors, photos, or fancy testing instruments especially when your sample area is limited by where robots can reach.
This is made doubly difficult when you don' t know exactly what your looking for. So I think its almost impossible that we will discover microbial life anywhere we aren't exploring in person.
Even then, mars methane bugs might be living a quarter mile below the surface and far out of easy reach. We could be living on that planet for decades and never know.
Larger life forms present a similar challenge.
I mean, what would an alien flower look like?
Flowers flower to attract other animals, not just because they feel like being pretty. Why would you expect a flower on Europa where surely no bees exist?
We might be staring at a field of carnations and never know it because they look like ice cubes.
May 6th, 2009 at 3:29 pm
Geological sources of methane have a different isotope ratio compared to biologically produced gas on Earth. A well appointed robot at say Nili Fossae should be able to make a similar determination should it exist on Mars.
May 6th, 2009 at 4:48 pm
Ah yes, the old "let's look for the key under the lamp post" pursuit.
I can agree with Dyson that "likely organisms" isn't the same as "organsism most likely to be found", if that is what he is out after. But I don't think his criteria cuts it as good as the former.
Bacteria is rather complex by their own, at least the kind that thrived on later days Earth.
"“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”)"
Not directly, since some bacteria can live on chemicals made in geothermal or radioactive processes. But perhaps to get started, say around sea hot vents.
"the seasonal methane could be due to some geologic process"
Personally I think the idea that methane is biological gets a real hit by the fact that all methanogens now seem to be the absolute latest metabolic and organismal development on Earth. Both Cavalieri-Smith wholesale classic phyologenetic analysis and some first attempts at wholesale genome analysis puts archaea as sisters to eukaryotes, and the methanogenic Euryarchaeota seems to be the youngest to boot.
This makes archaea and especially the methanogens nearly as derived as eukaryotes. And there is no evidence of convergent evolution of other methane producers that I know of.
If it is correct it doesn't mean that it is impossible that those developed elsewhere of course. But even if Mars is as old as Earth it seems a priori unlikely and contingent development.
"All due respect for Dyson, but he sounds like a loon whenever he spouts off about biology"
Yes. And he is claimed to be a contrarian.
OTOH I think he went before Kaufmann in studying autocatalytic systems, so he has probably done some good biology too.
May 6th, 2009 at 4:52 pm
Oops. Many errors here, but foremost: that should be Cavalier-Smith.
May 7th, 2009 at 1:01 am
I haven't read his paper, but Dyson is a big thinker, right? Dyson spheres etc… so perhaps he's not talking about the solar system. Within the solar system, within say 50 years, we'll "get down in the mud" and find the answer for every planet and moon.
Let's talk about bio-markers in extra-solar planets. Spectral analysis of atmosphere will probably be the leading tool for a first diagnossis. But it will be the detection of biomass, not of life. So perhaps he's suggesting that observation of color, polarity, and timing will be a useful tool.
Otherwise, if flowers are efficient receivers of light, then they don't reflect well. And if they are parabolic, then they can be observed from far away. But then again, the summary seems to be third hand reporting – the story doesn't even specify which conference this was presented in.
His quote is not even self-consistent – he wants to look for wierd life since "nature is wilder than our imagination", but then will go looking for poppies? sounds more like things are quoted out of context.
May 7th, 2009 at 1:02 am
Oh – and yeah – go Mars, I totally agree. By far the most interesting place to look next.
May 7th, 2009 at 6:46 pm
Clearly Dyson is right – it is almost a tautology. We will detect the most detectable lifeforms first, if they exist. Our searches should be geared to this fact. And flowers or plantlife would indeed be among the most detectable things we could imagine dwelling on a distant extrasolar planet (short of transmitting aliens, which we already know don't exist in our locale) – they have the power to change entire atmospheres. So it is likely that we would find these first, as opposed to something like and extrasolar slug.
However, I have a next to impossible time believing that there could exist any sort of flower or plant on Europa. He is right though – nature has always proven to have a far greater imagination than that of mere human beings.
May 8th, 2009 at 10:23 pm
“We never had as much imagination as nature.”
What're the chances that this is going to end up as an "example" that Freeman Dyson is *obviously* a creationist?