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The Colors of Extraterrestrial Life

One of these days we’ll have the instruments in place to examine light from a terrestrial-class world around another star. This opens up the possibility of identifying atmospheric gases like oxygen, ozone, carbon dioxide and methane. All of these can occur in an atmosphere in the absence of life, but if we find them existing simultaneously in great enough quantities, we will have detected a possible biosignature, for without life’s activity to replenish them, these gases would recombine and leave us with a much less tantalizing atmospheric mix.

But tackling planetary atmospheres for biosignatures is only one way to proceed. An interdisciplinary team led by Cornell University’s Lisa Kaltenegger and Siddharth Hegde (Max Planck Institute for Astronomy), is examining life detection based on the characteristic tint of lifeforms. An alien organism covering large parts of the planet — think forests, for example, on Earth — would reflect light at particular wavelengths, light that could be measured spectrally.

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Image: In this composite satellite image from NASA, you can see a greenish tint in the reflected sunlight, a direct signature of plant life present on Earth’s surface. Similarly, if microbial life with a particular pigmentation covered larges swathes of an exoplanet’s surface, its presence could in principle be measured directly through its tint in reflected starlight viewed through our telescopes. Credit: NASA Earth Observatory.

The challenge, and thus the burden of preliminary work on this concept, is to figure out what spectral signatures different kinds of organism might throw. Working with colleagues at NASA Ames, the researchers have put together a catalog drawn from cultures of 137 different species of microorganisms, seeking a wide range of pigmentation in species occurring in environments as diverse as Chile’s Atacama desert, Hawaiian seawater, old woodwork found in a Missouri state park and hot springs in the Yellowstone National Park. Focusing on extremophiles — life pushed to its limits — allowed the team to investigate the widest possible range for physical and geo-chemical conditions on the surface of exoplanets.

The method, examined in a new paper in Proceedings of the National Academy of Sciences, is to measure the chemical ‘fingerprints’ of each microorganism culture and make the findings available in an online catalog. Reflectance spectra are produced at optical and near-infrared wavelengths and assembled in the first such collection dedicated to surface biosignatures. The catalog was designed to reflect as wide a range of life as possible, understanding that on our own planet, dominant species have undergone huge changes.

From the paper:

Although there is a considerable knowledge base of the spectral properties of land plants, very little information is present in the literature on the reflectance properties of microorganisms. Land plants are widespread on present-day Earth and are easily detected from high-resolution spacecraft observations. However, they occupy only a small niche in the environmental parameter space that brackets known terrestrial life. Additionally, land plants have been widespread on Earth for only about 460 My, whereas much of the history of life has been dominated by single-celled microbial life. Within the prokaryotic and eukaryotic microbes there is a far greater diversity of pigmentation than in land plants. For this reason, any hypotheses about extraterrestrial life based solely on land plants ignore much of the diversity of known life.

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Image: Eight of the 137 microorganism samples used to measure biosignatures for the catalog. In each panel, the top is a regular photograph of the sample and the bottom is a micrograph, a 400x zoomed-in version of the top image. The scientists were aiming to achieve diversity in color and pigmentation. Top left to bottom right: Unknown species of genus bacillus (Sonoran desert, AZ, USA); unknown species of genus Arthrobacter (Atacama desert, Chile); Chlorella protothecoides (sap of a wounded white poplar); unknown species of genus Ectothiorhodospira (Big Soda Lake, NV, USA); unknown species of genus Anabaena (with green fluorescent protein; stagnant freshwater); unknown species of genus Phormidium (Kamori Channel, Palau); Porphyridium purpureum (old woodwork at salt spring, Boone’s Lick State Park, MO, USA); Dermocarpa violacea (aquarium outflow, La Jolla, CA, USA). Credit: Hegde et al. / MPIA.

The single-celled microorganisms that have dominated Earth’s history have flourished for 3.5 billion years and probably longer, and have demonstrated again and again that they can be found in the most extreme conditions, from inside nuclear reactors (Chernobyl) to deserts and polar regions. Their particular pigmentation will depend upon local environmental conditions, and thus their future detection by space-based telescopes will tell us something about the environment on the planet they inhabit. The reflectance from surface lifeforms also plays into models for exoplanets that can be used to study chemical processes in their atmospheres.

This news release from the MPIA distills the team’s methods for measuring biosignatures, a task performed by Hegde working with Lynn Rothschild and other researchers from NASA Ames:

Hegde, [Ivan] Paulino-Lima and [Ryan] Kent measured the sample biosignatures at the Center for Spatial Technologies and Remote Sensing (CSTARS) at the University of California, Davis. They used a setup called an integrating sphere, which is hollow and lined on the inside with a reflective coating. The integrating sphere contained a hole for the light source, the microorganism sample, and a detector to measure the fingerprint in the reflected light from the sample. The effect of the sphere shape is as follows: when light shines through the hole and reflects off the sample, it is distributed evenly in all directions. Therefore, the detector can be placed anywhere in the sphere, against any part of the wall, and still measure the same averaged (“integrated”) fingerprint. This is important because for the foreseeable future, telescopes will only be able to measure reflected light from an exoplanet that has been averaged over the whole of the visible part of the planet’s surface.

Lisa Kaltenegger, who heads up Cornell’s Institute for Pale Blue Dots, points to the wide range of possible life including extremophiles that occurs in the database, saying that it “…gives us the first glimpse at what diverse worlds out there could look like… On Earth these are just niche environments, but on other worlds, these life forms might just have the right make to dominate, and now we have a database to know how we could spot that.” The database, which is open for the free use of researchers worldwide, is located at the Institute.

Further additions to the database are expected in the future as more samples become available to catalog microbial reflectance spectra. The paper is Hegde et al., “Surface biosignatures of exo-Earths: Remote detection of extraterrestrial life,” in Proceedings of the National Academy of Sciences, published online before print March 16, 2015 (abstract). The catalog is Surface biosignatures of exo-Earths, now available online.

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Comments on this entry are closed.

  • Andrew LePage March 17, 2015, 10:10

    While this catalog would be useful for determining the presence of various lifeforms from Earth, its usefulness in “proving” an extrasolar planet has life (which would likely have very different characteristics) is dubious at best. Earlier attempts to do this during the first half of the last century that “proved” Mars had life only provided proof of the shortcomings of this approach.

    http://www.drewexmachina.com/2014/10/05/a-cautionary-tale-of-extraterrestrial-chlorophyll/

  • Alex Tolley March 17, 2015, 12:12

    Are terrestrial organisms going to be useful on worlds with different star types? For example, pigments are likely to be different on worlds bathed in light from M class stars compared to G types.

    Since our oceans are environments for algae, I would like to see that such a technique would work from a remote sensor looking at the Pacific ocean as a proof of concept. Would diatom signatures from the lab be matchable against the spectrum from the ocean? Perhaps such a test could be done from one of our future deep space probes?

    Won’t the diversity of spectra from different organisms, the atmosphere and the rocks make this a very difficult analysis to run against an exoplanet, even with high resolution spectral data?

  • Alex Tolley March 17, 2015, 12:19

    AAAS now has a new open access journal. There is a nice review article on detecting exoplanet biosignatures The search for signs of life on exoplanets at the interface of chemistry and planetary science

  • Windfire March 17, 2015, 14:37

    @Alex

    University of Washington’s Virtual Planetary Laboratory has modeled photosynthesis on worlds around different spectral type stars.

    http://depts.washington.edu/naivpl/

  • Ashley Baldwin March 17, 2015, 15:54

    This is why large aperture space telescopes are needed. At least 12m, preferably more , to get the kind of decent spectral resolution to pick out the various chemicals that facilitate the conversion ( via an electron transport system from donor molecules like water or hydrogen sulphide around those famous hydrothermal vents ) of simple elements like carbon dioxide into long chain molecules like sugars. Beyond doubt. That is how it will be when some bio signature or other is picked out from one planet or other unfortunately. Probably within twenty years. Ever increasing spectral resolution versus arguments for non biological causes.Actually imaging exoplanets to look at life is going to take serious technology breakthroughs and a shed load of money to build ,launch and link the massive arrays of large telescopes necessary .

  • andy March 17, 2015, 18:15

    The problem with these kind of predictions is that evolution does not produce optimal solutions, it produces solutions that work “well enough”, and is constrained by what came before. So you end up with non-optimal features such as airway-crossing-foodway in tetrapods, or the recurrent laryngeal nerve (which is ridiculous enough already in giraffes, but when you start to consider the RLNs of sauropods things become a whole level more absurd). So an exoplanetary biosphere may well end up dominated by a solution that is not optimal for the type of light the planet receives, but happened to get there first and occupied the relevant niche sufficiently well that it made it less favourable for something to move in with a more optimal form of photosynthesis. Good luck predicting what that will look like from a range of dozens of parsecs!

  • NS March 18, 2015, 1:40

    OT, but here’s an article on some recent research about the possible origins of life:

    http://news.sciencemag.org/biology/2015/03/researchers-may-have-solved-origin-life-conundrum

    The technical article is somewhat obscurely linked from within the above, but apparently requires a subscription to read beyond the summary.

  • Volucris March 18, 2015, 7:38

    Have to agree with Andy, just think about photosynthesis on earth, most plants are green, which doesn’t make any sense at all: green is smack in the middle (most energetic part) of sun’s spectrum, and still, green is exactly what the plants choose to throw (reflect) away, instead using red light! If plants were optimal, they’d all look black, like solar cells.
    Of course, there’s just that, if you see strange colors, with no other explanation, it might be life.

  • Harry R Ray March 18, 2015, 9:27

    Before you can even ATTEMPT to put a potentially habitable planet’s colors in any kind of proper context, you really need to know what the planet is like, geologically. We may be able to do this DECADES in advance of telescopes powerful enough to detect color variations. Check out the abstract: “Fourier spectra from exoplanets with polar caps and ocean glint” by P.M. Visser and P.J. van de Bult on Astro ph, and then, please read my comment about “Fourier Series” in the earlier post about the search for exorings

  • Alex Tolley March 18, 2015, 10:57

    @Volucris – chrolophyll absorbs red and blue light, which is why it appears green. Plants have also developed accessory pigments to capture other parts of the spectrum too. Optimality isn’t in one dimension, so it is quite possible that black plants are not optimal for selection by evolution.

  • Rob Henry March 20, 2015, 3:14

    I agree Alex Tolley, about what is optimal for life is different than for a solar cell, but you never told poor Volucris why.

    Life is not a static play but a growing game. For plants that entails growing faster than you are being eaten rather than sitting pretty in you final conformation. Light harvesting complexes cost energy to build, and are competing with many other possible investments, such as those that protect the plant from being eaten.

    Another thing to note is that many plants already DO produce more light harvesting pigments that is optimal for growth, presumably to deprive rival plants growing in the undergrowth of a chance to grow and to overshadow them.

  • Sarah Rugheimer March 22, 2015, 1:43

    @Andrew LePage: Note the authors only suggest that this should prioritize planets for further follow-up, not that it should by itself be considered a biosignature.

  • Alex Tolley March 22, 2015, 15:33

    @Rob many plants already DO produce more light harvesting pigments that is optimal for growth, presumably to deprive rival plants growing in the undergrowth of a chance to grow and to overshadow them.

    I did not know that. It makes sense though.

  • Dmitri March 24, 2015, 12:45

    Amazing. Curiosity has detected evidence of nitrates in Martian rocks. Specifically the SAM instrument detected signs of nitrogen in sample spectra in very big quantities.

    “When they finished, they were still left with a significant amount of nitrogen – enough to account for 110 to 300 parts per million of nitrate in the Rocknest sample, 70 to 260 parts per million in John Klein and 330 to 1,100 parts per million in Cumberland. That’s comparable to the amount of nitrates you’d get in extremely dry places on Earth, such as the Atacama Desert in South America.”

    http://phys.org/news/2015-03-nasa-curiosity-rover-fresh-ingredients.html

  • Dmitri March 24, 2015, 12:56

    Regarding the recent (very promising) findings of life (as we know it) precursors and elements I’m still deeply puzzled why we see all the hints to life but no life itself? Maybe it got sterilized and minimized into very specifics life forms (microbial mats) but didn’t have chance to evolve further (Stromatolites). I’ve got feeling Mars is sterile not just on surface but even underground.

  • Eniac March 24, 2015, 20:19

    Dmitri:

    Regarding the recent (very promising) findings of life (as we know it) precursors and elements I’m still deeply puzzled why we see all the hints to life but no life itself?

    It’s not all that puzzling, really. You wouldn’t be puzzled if you didn’t see a cake emerge after throwing flour, eggs and milk in a bowl, would you?

    The path from ingredients to end-product can be difficult, all the more so if there is no cook present.

  • Eniac March 25, 2015, 13:21

    As for trying to model the reflection spectrum for signs of life, I think a chemical approach based on systematic analysis of chromophores would be much more fruitful than looking at an arbitrary variety of Earth organisms. Photosynthesis requires chromophores, and their chemistry is pretty well studied.

    The problem with chromphores is that their spectral “lines” are broad, and thus not very distinctive. It might be better to look for vibrational spectra of complex molecules in the IR spectrum, if that is feasible.

  • Dmitri March 26, 2015, 6:40

    @Eniac

    I’m more into thinking of Jeremy England’s definition of life based on his tests & observations:

    “The formula, based on established physics, indicates that when a group of atoms is driven by an external source of energy (like the sun or chemical fuel) and surrounded by a heat bath (like the ocean or atmosphere), it will often gradually restructure itself in order to dissipate increasingly more energy. This could mean that under certain conditions, matter inexorably acquires the key physical attribute associated with life.”

    Industrially dried wood with ultrasound has more moist in it than Martian soil. Over many many eons hypothetical active underground microbial societies would eventually pop up to geologically dead Mars surface. So far only fossilized microbial mats has been identified but nothing else. Promising indigence yes but no palpable evidence of any life. In recent weeks circulating picture of Martian ocean points it was located only in the Norther hemisphere and covering no more than 25% of it. Everything else was dry land. When looking in details into Jeremy England definition the “heat bath” hints to clear abrupt access to heat source rendering the planet sterile. This in other hand pegs a question did Martian ocean had hydrothermal vent? It strongly hint hydrothermal vents are the key to evolution of life. Can the robotic program prove existence of hydrothermal vent on Mars? Based where the rovers have been & next ones planned to be they all venture at equatorial latitudes & none of them is planned where the ocean floor was. In a row it raises fundamental question – do we need to continue searching life on most likely unfavorable place like Mars rather than concentrate efforts on most obvious places like the ones that have protective atmosphere – Venus, Titan. I’m rather skeptical of life on Titan in any shape. NASA’s recent presentation of its budget goals for exploration programs till 2030 has no Venus missions in plan. ESA might have another one but AFAI remember it’s too beyond 2030. Still inconclusive results of Mars missions since the Viking ones is sufficient to make due diligence & redefine the goals for search of life in the Solar system. All the efforts have shown it’s time to move on as ESA & NASA has plenty robotic missions (Opportunity, Venus Express, Messenger) that have outlived it’s primary & consequence mission goals & need to be retired rather than dying in sudden death. That means the skills of building robotic crafts have reached plateau & we are more than ready to tackle on next challenging celestial bodies with environments. Nowadays known materials that can withstanding harsh conditions of Venus surface are accessible, question is where to harvest its potential.

    That was the reason of my pondering having all the ingredients still can’t spot cake nor sauerkraut in any shape of form nor geologically recently of far far past.

  • Rob Henry March 26, 2015, 23:11

    Dmitri, yes under highly specific circumstances in far from equilibrium systems complexity can grow a little.

    This way of adding complexity is non teleological, so the more complex the object we hope for, the more ridiculously low the probability. If we are the insanely optimistic sort, we might hope these primordial oceans construct a universal computer or automobile for us to drive. Designing a self-replicating machine is currently beyond us, so this is the least likely outcome of all.

    Okay, there might be some grain of truth in your “This could mean that under certain conditions, matter inexorably acquires the key physical attribute associated with life”, but you have completely lost it when you assume that solves abiogenesis and you can move on.

  • Dmitri March 27, 2015, 15:40

    I’m the wrong guy to address, better take Jeremy England on. Regarding him I’m in total favor of his research as it evidently shows he tends to be right & can address all the critics.

    1) His an hour long lecture in Karolinska Intstitude (highly recommended) – https://www.youtube.com/watch?v=e91D5UAz-f4

    2) A podcast him answering the hos question regarding protein folding abilities (even more highly recommended) – https://www.youtube.com/watch?v=QRXrV3C7gwk

    What Jeremy England has discovered is the notion chemistry tends in favorable circumstance move towards life if proper thermal bath is present (input energy).

    I think there should be reconsideration of what we are doing in terms of search of live with inconclusive results of past 50 years having now new insights on looking on how life tends to form.

    In short – what all the right ingredients but no life shows (per Jeremy England work) is the lack of thermal bath (no hydrothermal vents) is most likely reason of no life if the atmosphere disappears due to harsh cosmic weather.

  • Dmitri March 27, 2015, 16:12

    Side Note:
    When juxtapose the Great Silence, 50 years of still inconclusive results from Mars, abundance of ingredients for life in the Universe, hints to the Great Filter – emergence of single cell, and/or jump to multi cellular, is (very) rare.

    Concluding this is difficult but when regarding Jeremy England’s work starting to make the case.

  • Eniac March 30, 2015, 19:15

    I do not think England’s work can or does address the problem of minimum complexity of a self-reproducing system. That would be von Neumann’s domain, not that of the the Prigogine/England crowd. If it was as easy as some (hopefully just the popular press) make it sound, England (or someone else) would have no trouble producing a novel kind of life in the lab. Not only has that not happened (nor will it, I bet), there is also no evidence that there was ever a second form of life on Earth during all of it’s billions of years of existence. So, if you ask me, concluding that the emergence of life is extremely rare is not difficult, at all. Rather, it should be considered the default assumption.

  • Mark Zambelli April 2, 2015, 12:01

    Dimitri…

    “So far only fossilized microbial mats has been identified but nothing else. Promising indigence yes but no palpable evidence of any life.”

    The first sentence above requires more clarification… namely that this is the take of a Dr Noffke as reported here http://www.sci-news.com/space/science-curiosity-ancient-microbial-life-mars-02389.html (there are numerous webpages devoted to this topic going back to 2004 so that link is just for a flavour). Fossilized microbial mats have NOT been identified on Mars; whether this parediola can be backed up with some hard data from SAM or Chemin etc remains very much to be seen.

    No matter how gradual a change Mars underwent, I personally find it hard to imagine any hardy organisms surviving at or near the surface. If (and it’s still a relatively big ‘if’) microorganisms did flourish in the early martian environment and if they were able to retreat to niches underground (while their peers perished aboveground), maybe a point was reached where none of the survivors stand any chance of evolving to cope with those conditions. As time went on the situation became increasingly dire effectively sealing their fate to forever remain sub-‘terranean’ (insert martian equivalent word there).

    I hope Mars has life but finding evidence at the surface could well be impossible after all this time even while keeping structures such as stromatolytes and mats firmly in our thoughts. I would love to be shown otherwise however.

  • Dmitri April 10, 2015, 3:56

    @Mark Zambelli, @Eniac

    I should have said “promising candidates”. Dr Noffke is a reasonable person & she is very precise what she means. In that term I referred more to her sighting on promising candidate as the expert on microbial mats. She has many times specifically pointed that whether or not they are what she thinks might be the sediments have to be measured and examined. NASA has heard her call & they are in negotiation on collaboration. Curiosity has all necessary tools to perform the observation she intended. By she I don’t mean her alone but all the collaborators who wrote the paper she published in mid December.

    The fact what we have to acknowledge is the example of how life evolved on Earth. For 4,5 Gyr Earth has only had single cell micro organism. Only in last 1 Gyr we have seen the life as we know it – namely multicellular. In terms on galactic years from 18 galactic years (250 Myr = 1 galactic year) the life have started to evolve (into multicellular) only in last 4 yr (max).

    Water on Mars has been per current estimation for 1,2 Gyr meaning that is too short period for such evolutionary change. It also requires big & strong strong microbial colonies. What microbial life has show on Earth that sooner or later their activity will be noticeable on surface. No matter is this as living or fossilized form. Recent strong evidence of existence of necessary precursors for life and no evidence whatsoever for any activity, namely constant inconclusive evidence since Viking missions, more & more hints to obvious conclusion that if on Mars there ever was life (microbial) then it’s dead & the planet is sterile despite promising finds in chemical components. The reason why is not because of Mars climate, atmosphere or too short period of water on the surface but the question did Mars ever had any thermal vents on the bottom of the ocean.

    Science has evolved in big strides since beginning of the Viking missions & we have more insight into interpreting the results to correct the efforts for search & finding evidence of life – namely microbial, probably single cell only, most likely fossilized. If put Jeremy England definition of how components of biochemistry tend to reorganize so they eventually tend to evolve into biological life IF there is sufficient thermal bath. This leads to presumption that stable thermal bath is more important than sufficient access to nutrients. How come? Look at the Snowball Earth!

    BBC recently run a story “Earth was a frozen Snowball when animals first evolved” (1). Most fascinating is the fact that for Cambrian explosion we had Snowball Earth due to overproducing oxygen by stromatolite. It happened not 1 Gyr back but mere 713Myr. 300Myr later. Multicellular life itself is a half a Gyr miracle – a mere 2 galactic years. Nothing in geological or astronomical terms.

    Some very relevant quotes from the article:
    ”Around 540 million years ago, a host of exotic creatures suddenly appeared. They included giant woodlouse-like creatures known as trilobites, the five-eyed Opabinia, and the spiny slug-like Wiwaxia. Suddenly, Earth leapt from being dominated by single-celled bacteria to a world teeming with exotic multicellular creatures, all in a geological blink of an eye.”

    ”The idea is that the ice gave a boost to microscopic plants, which released oxygen as a waste product. During the Snowball, the glaciers would have worn huge amounts of phosphorus-rich dust away from the underlying rocks. Then, when the ice retreated at the end of the Snowball, rivers washed this dust into the oceans, where it fed the microbes.
    “High phosphorus levels would have increased biological productivity and organic carbon burial in the ocean, leading to a build-up of atmospheric oxygen,” says Noah Planavsky of Yale University in New Haven, Connecticut. In 2010 he identified a massive spike in phosphorus levels in sediments from around the world, just as Snowball Earth was ending.”

    ”In recent years another idea has come to prominence. Maybe it was the ice itself that drove the evolutionary leap, says Richard Boyle of the University of Southern Denmark in Odense. “There are no animals more complex than a sponge prior to the last of the Snowball glaciation events, and in my opinion this is not coincidence,” says Boyle.
    For Boyle the real puzzle isn’t the appearance of multicellular animals. Instead, it’s the rise of cellular differentiation – cells with specific roles like liver, muscle and blood. These specialised cells allowed animals to become much more intricate. “What sets animals apart from plants and fungi is this irreversible cellular differentiation, which, for instance, is what allows animals to have more cell types,” says Boyle.
    It’s hard to see how this could have evolved, because specialised cells lose the ability to reproduce on their own. Instead they have to be distinctly self-sacrificing, cooperating with other cells in the body for the greater good of the animal. Only the specialised reproductive cells, the sperm and eggs, get to create a new generation. By contrast, plants don’t just rely on specialist sex cells to reproduce. They can also reproduce themselves from cuttings taken from their stems or roots. “You can’t take a cutting from an animal,” says Boyle. He thinks the severity of Snowball Earth may have pushed animal cells to abandon this flexibility, and specialise.”

    Now comes the contra argument but it’s exceptionally relevant:
    ”Boyle’s notion is controversial and other scientists are sceptical. “Boyle’s melt-hole idea for the origin of animals is fun,” says palaeontologist Nick Butterfield of the University of Cambridge, UK. “But most geologists don’t buy the idea of a hard Snowball Earth anymore, so the isolated hot-spring refugia ponds wouldn’t have actually existed.Butterfield argues that life probably retreated to the open waters of the tropics during Snowball times, but otherwise carried on as normal.”
    Butterfield argues that life probably retreated to the open waters of the tropics during Snowball times, but otherwise carried on as normal.”

    Regardless did multicellular differentiate & cooperate or just survived in refugia what they both say in common is the absolutely minimum requirement for life to continue evolve is access to & existence of sufficiently stable thermal bath (to stick to Jeremy England’s terminology).

    BBC again neatly runs another story: “Europa may be home to alien life” (2)

    ”JUICE won’t specifically look for life, but it will try to find out what Europa’s ocean is like. The first step is to find out how deeply it is buried. The answer may be: not very deep at all. An analysis by Nasa researchers in 2011 suggested that there is only about 3km of ice overlaying the ocean. That is thinner than many areas of the Antarctic ice sheet. JUICE will use radar to find out if this is true, and map out Europa’s internal structure.
    JUICE will also investigate what is going on at the bottom of the ocean. A key question will be whether there are hydrothermal vents: jets of hot chemical-rich water shooting out of the sea floor. These vents could supply the energy for life in the ocean, just like they do in the depths of the sea on Earth.
    So far there is no direct evidence that Europa has hydrothermal vents, but JUICE might be able to help. It could find some crucial evidence drifting above Europa’s surface – if, that is, Europa is anything like Enceladus.”

    The whole ESA JUICE program benchmarks to results of lake Vostok, Ellsworth, & Whillans in Antarctica. Although the BBC article easily disregards 2012/2013 lake Vostok drilling sample result & praises the UK & USA team Sergey Bulat (Сергей Булат) from St. Petersburg Nuclear Institute who runs the lake Vostok drilling operation have specifically restated(3) that from 2012/2013 samples from frozen lake ice on the drill they have found 48 contaminants, 2 unidentified microbes from which one is up to 86% with matching DNA genome meaning it’s completely alien life form to Earth & not in microbial tree of life database. Any claims on contaminants & them rendering the results unreliable, specifically labeling the method as typical Soviet approach for getting samples, is unjustified & long been discussed, explained, & agreed with the international community. He points out that the Americans reaching lake Whillans is non-event as it’s drifting sea melt water in the glacier plus the lake is too shallow. The Brits failed to reach lake Ellsworth due to technical glitch and exhausting all the fuel gleaned over 2 years there halting the activity in they camp until 2018. He also stressed that the presentation of the results on lake Vostok findings have been done in October 2012 in Stockholm during the 14th European Astrobiology Conference and in March 2013 during International Colloquium & Workshop “Ganymede Lander: scientific goals and experiments”(4)

    (Although the latter presentations are all in English for some reason I can’t find any related to his one. None the less all the materials there is fascinating inside how an unmanned mission to Ganimedes has to be carried out & what are the scientific goals).

    Sergey Bulat (Сергей Булат) in the interview from November 2014(5) neatly describes that they brought up in 2013/2014 samples from top frozen layers of lake Vostok & in cooperation with French biologically clean labs tested out the hypothesis the frozen upper sediments on top of the lake should have been gathered over 10 000 years, thus having sufficient quantities of evidence to test out does or doesn’t lake Vostok have markers of biological life. The result was promising. The plan for 2014/2015 is to bring live water sample from the lake itself in titanium canisters which will be take directly from the lake to preserve all the conditions of the sample when it was taken, including the microbial evidence – clean, uncontaminated, live, preserved in the conditions what the lake had when the sample was taken. The plan is to carry out in spring 2015 and in May 2015 bring it back to labs to have preliminary result by summer 2016.

    Per current plans for lake Vostok in 2015/2016 they plan to take uncontaminated water samples from 0 meters, 100 meters, 120 meters, 300m up to 700m. What Sergey Bulat has also predicted that lake Vostok has hydrothermal vents.

    Does or does it not will be attempted to be proven via uncontaminated sampled directly from the lake. The deeper the sample the greater probability of discovering life in it. So far lake Vostok is the only promising source for proving probability of extraterrestrial microbial life within the Solar system. All the else lakes are inconclusive & unsuitable.

    To conclude the long write-up it seems we talk about the same thing just everyone have their own caution approaching conclusion. Discussing here it strike me that we already have all the necessary pieces of puzzle to build a new direction of the quest – namely search for life on bodies with atmosphere & planetary crust. Per example life on Earth shows neatly life as we know it have too long persisted in the form that didn’t evolve to anywhere & only (the latest, third (??)) Snowball Earth event pushed it in duress where it had to differentiate, cooperate, commune, rely on each other but most crucially – it had the stable thermal bath in form of either thermal vents or Earth’s atmosphere. Most probably it was thermal vents as Mars example shows diminishing atmosphere didn’t leave any chance to any life in any form unless the thermal bath would have supported it from the inside the planet’s core. That’s why we don’t see any evidence of any form of microbial activity on the surface despite of 4,5Gyr of Mars age because the microbial colonies that buried underground in attempts to survived died off from luck of thermal bath in form of hydro thermal vents. Maybe 1,2Gyr of ocean on the Martian surface is not sufficient either but all signs show mars is completely sterile. IF Dr. Noffke theory of fossilized microbial mats turns to hold the ground then we at least might conclude that to some extent life tries to emerge but it’s up to the planetary internal conditions in terms on thermal activity weather it will provide sufficient environment for any development or it’s basically a biological Russian roulette with fully loaded barrel where very rarely some bullets misfire (thermal bath is stable enough for sufficient longer period to multicellular to be evolved & morph into form necessary for emergence of far complex life forms).

    That’s why we should regard as life is (very) rare because the space have not many planetary bodies that can sustain such favorable conditions.

    The question whether or not Europe, Encaledus has thermal vents & what exactly is life in terms of lake Vostok samples, will be answered in next decade (2025) but the definitive answer to the notion will be reached withing following decade (2025-2035). Maybe two (.. – 2045).

    If all goes well for SpaceX plans then by 2040/2045 we should have first settlers on Mars speeding up the process of answering of this constantly inconclusive quest.

    Very open for feedback.

    (1) http://www.bbc.com/earth/story/20150112-did-snowball-earth-make-animals
    (2) http://www.bbc.com/earth/story/20150326-europa-may-be-home-to-alien-life
    (3) http://www.aari.ru/docs/press_release/2013/NTBxtr.pdf (in Russian)
    (4) http://glcw2013.cosmos.ru/presentations (All in English)
    (5) http://www.priroda.su/item/7327 (in Russian, exceptional infographic on lake Vostoke drill holes)

  • Dmitri April 10, 2015, 4:10

    Small side note:

    By “namely search for life on bodies with atmosphere & planetary crust. ” I mean directly Venus & Titan as the only Solar system bodies with the features as we can relate to Earth & appreciate difficulties in observing the environments. Does Europa, Encaleduse, Ganimedes fall into the same category is more complex question as we lack any knowledge of possible microbial life in hydrothermal vents only environments.

    NASA does not have any Venus mission plans up until 2032. ESA might have follow-up to Venus Express but unclear when. If, then most likely very close the 30’s. Titan per se is not on the radar because its atmosphere & planetary crust doesn’t click in our heads as the destination for search of life not-as-we-know-it.

    I don’t think gas giants are in our vocabulary for life at all at least per current knowledge & recent understandings.

  • Dmitri April 10, 2015, 16:26

    Just FYI on lake Vostok. Article by Sergey Bulat on Jan 21 2015.

    1) The lake has up to 50 times more oxygen than average water.
    2) Average temperature of the lake is +10C that is the premise for hydrothermal vent claim.
    3) Pressure 300 atm – 304 bars/ 30,4 MPa. Average ocean pressure is up to 100 atm.
    4) On Jan 25 2015 they reached the lake on depth 3769 m & 15 cm. The titanium vessel for taking pristine water samples is 2 meter long, weighing 50 kg, capable of taking 1 liter of water right into airtight inner vessel.
    5) Despite reaching the lake again by drilling a new hole they did not manage to get any samples.

    In short – chances for 2015 are basically over. Now the goal is to have them by 2016.

    http://www.mk.ru/science/2015/01/26/rossiyskim-uchenym-poka-ne-udalos-vzyat-probu-vody-iz-ozera-vostok.html