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Rio scale

  1. 1. IAC-10.A4.2.3 SETI AND ASTROBIOLOGY: THE RIO SCALE AND THE LONDON SCALE Iván Almár Konkoly Observatory of the Hungarian Academy of Sciences, Budapest, Hungary almar@konkoly.huThe public reaction to a discovery, the character of the corresponding risk communication, as well as the possibleimpact on science and society all depend on the character of the phenomenon discovered, on the method ofdiscovery, on the distance to the phenomenon and, last but not least, on the reliability of the announcement itself.The Rio Scale – proposed together with Jill Tarter just a decade ago at a similar symposium in Rio de Janeiro –attempts to quantify the relative importance of such a “low probability, high consequence event”, namely theannouncement of an ET discovery. After the publication of the book “The Eerie Silence” by Paul Davies it isnecessary to control how the recently suggested possible “technosignatures” or “technomarkers” mentioned in thisbook could be evaluated by the Rio Scale. The new London Scale, proposed at the Royal Society meeting in Januaryin London, is a similar attempt to quantify the impact of an announcement regarding the discovery of ET life on ananalogous ordinal scale between zero and ten. Here again the new concept of a “shadow biosphere” raised in thisbook deserves a special attention since a “weird form of life” found on Earth would not necessarily have anextraterrestrial origin, nevertheless it might be an important discovery in itself. Several arguments are presented thatmethods, aims and targets of “search for ET life” and “search for ET intelligence” are recently converging. The newproblem is raised whether a unification of these two scales is necessary as a consequence of the convergence of thetwo subjects. Finally it is suggested that experts in social sciences should take the structure of the respective scalesinto consideration when investigating case by case the possible effects on the society of such discoveries. I: INTRODUCTION unambiguously considered a threat or catastrophe for humanity, nevertheless the announcement of such a This paper is partly based on my presentation at claim can be ranged rightfully among the lowthe Discussion Meeting of the Royal Society “The probability, but high consequence type events ofDetection of Extra-terrestrial Life and the human history. The media would like to know theConsequences for Science and Society“ (January, exact interpretation immediately, although it is2010). London) and partly reacts upon some important improbable that this claim can be met by the ideas raised by Paul Davies on the same meeting. Although it seems to be certain that such a discoveryIt is a challenge to make the two scales, the Rio Scale would have a long lasting effect on science andand the London Scale consistent with such original society, the couple of announcements on a discoveryconcepts like a “shadow biosphere” and fantastic of ET life up-till-now had not been accepted as fact bytechnomarkers (or ‘absent exotica’) respectively as the scientific community and had only passing effect.described in his book “The Eerie Silence”. (Davies The main purpose of the two scales discussed in this2010) paper is just to give a tool to those who are asked to evaluate an announcement of a putative discovery. II THE PURPOSE OF THE SCALES This flexible tool can make the communication with the press and through the media to the public easier. There are different simple scales in permanent use There is also a secondary purpose. The real effecttrying to quantify the a priori risk and also the a of such an announcement on society is the topic ofposteriori effect of serious and dangerous terrestrial several investigations worldwide. It was already thephenomena like storms, earthquakes, hurricanes, solar main topic of a high level Discussion Meeting of theoutbursts and recently the threatening approach of a Royal Society in January and a follow on meetingNear Earth Object as well (Beaufort, Richter, Saffir- with panel discussions is planned by the Royal SocietySimpson, Torino scales etc.). The Rio Scale (Almár and IAA in early October. In all these discussions it isand Tarter 2000) attempts to quantify the relative crucial to clearly indicate the kind of phenomenon inimportance of the announcement of a discovery of question, because the effect to be expected depends onextraterrestrial intelligence; the London Scale (Almár different parameters: the class of phenomenon, theand Race 2010) is a similar attempt to quantify the discovery type and the distance. This is obviously trueimpact on an announcement regarding the discovery also if the associated risk is estimated.of ET life on an analogous ordinal scale between zero Can such scale values help also in an a priori riskand ten. Although the discovery of an independent life assessment? Sometimes yes, sometimes it is doubtful.or extraterrestrial civilization can not be In a third scale proposed to be used for active SETI or 1
  2. 2. METI experiments (the San Marino Scale in 2005) it radio telescopes; and astrobiologists may not need tois rather clear that a larger SMI value belongs to a rely only on tangible samples brought back byhigher risk (Almár and Shuch 2007). In the Rio scale spacecraft from a nearby planet. Today there are otherthe RSI value has already not such a direct connection possible discovery scenarios both in SETI andto risk (if there is any) and in the London scale we astrobiology research that could result inhave completely separated the treatment of the risk announcements of important discoveries. To addressproblem. the scientific complexity and possible confusion associated with announcements about purported III.NEW CONVERGENCE IN ASTROBIOLOGY discoveries of evidence for ET life, the London scale – AND SETI similar in conception and structure to the Rio Scale – has been proposed this year for evaluating the Fifty years ago SETI started as a simple project in importance, reliability and associated risk of aradio astronomy searching for artificial ET signals and discovery of ET life that is presumably non-intelligentmessages in the microwave spectrum coming from and relatively nearby (in the Solar System or Galaxy).interstellar distances (Project OZMA). Somewhat later Such a scale may be useful when communicatingone might say that the astrobiology (at that time called about the complex factors involved in evaluating newexobiology or bioastronomy) began its early searches astrobiological ‘discoveries’ of ET life.for possible ET life within the solar system whenNASA sent space probes to Mars with sophisticated IV.THE RIO SCALE: DO WE NEED TO MODIFYequipment looking for simple life forms based on life IT?as we know it (Viking missions in 1970’s). In thefollowing decades the basic principles did not change: IV.I.The Rio Scale for a putative discovery ofthe SETI community carried out searches using more extraterrestrial intelligenceand more sophisticated radio telescopes and In anticipation of the likely public interest inmultichannel spectrum analyzers, with targets being detection of a putative extraterrestrial signal orstrictly outside the Solar System; and astrobiologists artifact, the Rio Scale was developed as an ordinalcontinued to focus on planetary missions and research scale valued between zero and ten, to quantify thewithin the Solar System. impact of any public announcement regarding In the last 15 years, however, as conventional evidence of extraterrestrial intelligence orsearches continued, some unconventional suggestions technological civilization. The concept was firsthave emerged in both communities. For example, proposed by Almár and Tarter (2000) at a SETIsearches for extraterrestrial artifacts (SETA) have symposium in Rio de Janeiro (hence its name) in orderbeen proposed and carried out in the Solar System and to bring some objectivity to the otherwise subjectiveastrobiologists have studied meteorites in order to find interpretation of any claimed ETI detection.traces of extinct ET life. Recently both SETI andastrobiology communities have became interested in Structurecarrying out „targeted searches” of potentially As originally proposed and subsequently refined,habitable extrasolar planets (e.g., the Kepler mission, the present Rio Scale Index (RSI) is mathematicallythe Gaia and the Darwin missions). Further, the SETI defined as:community has accepted that investigations in the RSI=Q x !optical and infrared regions might also be useful. The where Q, an estimated level of consequences, is theastrobiology community has accepted that optical sum of three parameters, and δ represents the assessed(spectroscopic) observations of exoplanets might be of credibility of a claimed discovery. The value for Q isinterest when looking for biomarkers (e.g. biogenic quantified as a function of the class of the reportedatmospheric signatures associated with known living phenomenon, the type of discovery, and the estimatedsystems). Thus, what were initially very different distance to the phenomenon detected. SETA meanstargets and search methods used in SETI and Search for Extraterrestrial Artifacts. (A credibleastrobiology respectively, seem to be converging. artifact would constitute evidence for intelligent ET What does this trend mean for the future life even without ET beings.) The value assigned for δannouncement of a putative discovery of either ET life is somewhat more subjective, and is likely to varyor ET intelligence? The simple old assumptions are over time. Table I shows the values assigned to thenot valid anymore. A SETI discovery need not be three Q-associated parameters and the reliability factorconfined to far away phenomena registered only by in the RSI. 2
  3. 3. Class of Phenomenon Value Traces of astroengineering or indication of technological activity by an extant or extinct civilization at 1 any distance, or an ET artifact, the purpose of which is unknown Leakage radiation, without possible interpretation, or ET artifact whose purpose is understandable 2 Omnidirectional beacon designed to draw attention, or ET artifact with message of a general character 3 Earth-specific beacon to draw our attention, or an ET artifact with a message to mankind 4 Omnidirectional message with decipherable information, or a functioning ET artifact or space probe 5 Earth-specific message, or an ET artifact, capable of contact, or a physical encounter 6 Discovery Type From archival data; a posteriori discovery without possibility of verification 1 Non-SETI/SETA observation; transient phenomenon that is reliable but never repeated 2 SETI/SETA observation; transient phenomenon that has been verified but never repeated 3 Non-SETI/SETA observation; steady phenomenon verifiable by repeated observation or investigation 4 SETI/SETA observation; steady phenomenon verifiable by repeated observation or investigation 5 Dis Distance Extragalactic 1 Within the Galaxy 2 Within a distance which allows communication (at light speed) within a human lifetime 3 Within the solar system 4 Reliability Factor (!) Obviously fake or fraudulent: 0 Very uncertain, but worthy of verification efforts: 1/6 Possible, but should be verified before taken seriously 2/6 Very probable, with verification already carried out 3/6 Absolutely reliable, without any doubt 4/6TABLE I. Parameter values and reliability factor associated with the Rio Scale Index Selecting the relevant line in each of the three completely new idea, mentioned as ‘absent exotica’,parameter sub-categories and adding the three that the lack of something in the macrocosmos or innumbers at the end of each line gives a Q value from 3 the microcosmos might also be a kind ofto 15. If a sub-category is uncertain, two limiting technosignature. Davies enumerates some of them invalues for Q can only be determined. Then, his book as follows: hijacking the missing extrasolarmultiplying the Q value by the reliability factor (!) comets, or blowing up a protoplanet between Marsyields an RSI value that can range from 0 to 10 and Jupiter in the Solar System, or at the other end of(eleven separate qualitative categories). The zero to the mass range mini-black holes, quark stars, cosmicten ranking is essentially an interpretation that a strings, magnetic monopoles – their existence isdiscovery is meaningless or insignificant (0, 1) to predicted by theory, but nobody could find them up-moderate (4) to extraordinary (10). till-now. Over time, the RSI values assigned to any SETI If the term “artifact” is changed todetection can be expected to change – either upward “technomarker” than a part of the problem of theseor downward – to reflect new information about the possibilities might be solved. Technomarker maysignal. The RSI was accepted by the SETI Committee mean any sign of an existing or extinct technicalof the International Academy of Astronautics (IAA) in civilization – except a message or a beacon which2002. belongs to traditional SETI. In some cases it would be difficult or impossible to decide the distance or theIV.II.Technomarkers instead of artifacts? type of discovery; in cases when the lack of something According to the ideas raised or summarized in is suspicious to the experts we are helpless in(Davies 2010), the possibility of the discovery of any particular. In these cases it is difficult to interpret thesign of a technical civilization should be taken into distinction between “SETI/SETA observation” andaccount, not only active or passive artifacts on “non SETI/SETA observation” , although a high levelcelestial bodies within the Solar System. There might of expertise is definitely needed in such dubious casesbe also different kinds of unusual “technomarkers” or before a decision is made how probable or improbable“technosignatures” mentioned by Davies as “alien a natural interpretation of the phenomenon in questionmagic” or “technology as ‘nature plus’”. It is a might be. 3
  4. 4. V.THE LONDON SCALE: DO WE NEED TO structure or chemical composition, or in the extreme, MODIFY IT? to a completely alien life form.V.I.The London Scale for ET life Nature of the evidence, which focuses on the In the section below, we introduce the London variety of possible forms that may be associated withScale for astrobiology (proposed at the Royal Society the evidence (alive, dead, dormant, pieces, fossil,Discussion Meeting in January 2010 in London, hence biomarkers, etc.) Different values are assessed acrossits name) whose structure and logic are intentionally the range of evidence from chemical biomarkers,analogous to the Rio Scale for ET intelligence. It has fossils or dormant states, to obviously organizedbeen developed as an ordinal scale with index values simple or complex life forms.between zero and ten, which can be used to evaluateand present complex information about the scientific Type or method of discovery, which focuses onimportance, validity and potential consequences of an how directly or indirectly the phenomenon can bealleged discovery of ET life via various studied, ranging from remote sensing approaches toastrobiological methods and within the Solar System manipulative methods, direct observation of materials,or Galaxy. The London Scale Index (LSI) is and experiments.mathematically defined as: LSI = Q x ! Distance to the discovered life form, which iswhere Q, (importance) is the sum of four parameters also considered, relates indirectly to how detailed and(the life form, nature of evidence, method of repeated the study of the discovery can be. Distancediscovery, and distance), and ! represents the assessed values vary based on whether the discovery is beyondcredibility of a claimed discovery. the Solar System, at intermediate distances where in The Q factor is quantified based on specific situ research may be possible, or on Earth.values assigned to key phenomena and methods of thediscovery. The first two parameters relate to the class Similar to the Rio Scale, the assignedof phenomenon discovered, the other two relate to credibility value ! is somewhat more subjective andmethods and distance, as follows: likely to vary over time as new research or findings add useful information. Type of life discovered, which may range fromsomething similar to terrestrial life, to a variant in Class of Phenomenon: Life Form Value Possible signature of life, but indirect information only (e.g. volatile, trace) 1 Terrestrial type life form, but some uncertainty remains 2 Life definitely, but a previously unknown variant of terrestrial life (in structure or 3 composition) (e.g. if DNA is present, different amino acids are used) Likely to be non-terrestrial, but some uncertainty remains 4 Completely alien life form 5 Nature of Evidence Biomarkers (indirect evidence, like volatiles, metabolites, biochemical signatures etc.) 1 Fossilized life or remnants of life forms 2 Uncertain whether living or not (like a virus) 3 Extant life with suspended functioning (like a spore) 4 Simple life (low level of organization) 5 Complex life (high level of organization) 6 Type or Method of Discovery By remote sensing from the surface of the Earth or from satellites, flybys etc. 1 By a surface robot, in situ, on another celestial body 2 By a manned mission, in situ, on another celestial body 3 By analyzing something found on Earth’s surface or in the atmosphere 4 (e.g., meteorite, atmospheric sample) By analyzing the result of a sample return mission (origin of the sample is well known) 5 4
  5. 5. Distance to The Discovered Life Form at Time of Announcement Beyond the Solar System (in situ research impossible) 1 On or outside the orbit of Jupiter, but in the Solar System (in situ research possible, but 2 difficult) Inside the orbit of Jupiter (in situ research more easily possible) 3 Zero distance (on Earth) 4 Reliability Factor (!) Obviously fake or fraudulent 0 Probably not real 0.1 Controversial, but not rejectable 0.2 Testable, needs further evidence 0.3 Probably real 0.4 Certain or highly reliable 0.5TABLE II. Definition of different parameters: the scales for the four parameter values as well as the categories used to rate the reliability factor Selecting the relevant line in each of the four V.II.Weird life and shadow biosphereparameter sub-categories and adding the four numbers In his book “The Eerie Silence” Paul Daviesat the end of each line gives a Q value from 4 to 20. If writes in a chapter on Seeking a Second Genesis ona sub-category is uncertain, two limiting values for Q Earth:: “If life started more than once on Earth, wecan be determined. Then, multiplying the Q value by could be virtually certain that the universe is teemingthe reliability factor (!) yields an LSI value that can with it. Unless there is something very peculiar aboutrange from 0 to 10, with higher values indicative of our planet, it is inconceivable that life would havemore scientifically important, credible discoveries. begun twice on one Earth-like planet but hardly everThe London Scale value assigned to any ET discovery on all the rest.” “Direct confirmation could come fromcan be expected to change – either upward or the discovery of living descendants of other genesisdownward – over time as new findings or research events, sharing our planet with us, and constituting aprovide additional information. shadow biosphere.” ”Life today is represented by Undoubtedly, if a claimed discovery involves life millions of different species, but if we trace evolutionforms that are complex or dissimilar to terrestrial backward over billions of years, then they converge onforms and involves direct scientific method(s) and the ‘trunk of the tree’.” “The question I am raising –instruments used on Earth by researchers, it is likely to writes Paul Davies – is simply, does all life on Earthbe viewed as more credible evidence for ET life than belong to this single tree, or might there in fact besomething studied only afar and by remote methods. more than one tree?” He summarizes why biologistsAlready, we can anticipate a variety of discovery think all known life shares a common origin: “Thescenarios that may involve media announcements main evidence comes from biochemistry andabout ET life. Experience has shown that some molecular biology.” All known living creatures – asdiscoveries involve long-term scientific research far as we know – “use DNA and RNA to storedebates (e.g. microfossils in the meteorite information, and proteins to serve as enzymes and asALH84001), while others are more hypothetical (e.g. structural building blocks. Energy is stored andMartian Surface Organisms on Dark Dune Spots) or released using molecules known as ATP. “ “The factrepresent questionable phenomena not generally that such complicated and specific features asaccepted yet (e.g. different evidences of panspermia); ribosomes, ATP and the triplet code are found to bestill others may be lacking decisive scientific support universal would be hard to explain unless all the(e.g. Red Rain in Kerala) or remain highly suspect as species had descended from a universal ancestor.” Hehoaxes. Applying a standard scale to various adds that “Astrobiologists refer to known organisms as‘discoveries’ is a way for the science community and ‘standard life’ and to the hypothetical alternativethe public to examine the disparate factors that go into forms as ‘weird life’. (Weird life could be alien life ina claim or announcement. In addition to ranking the the sense of ‘not one of us’, but also in the sense ofdiscoveries, such a scale is useful to highlight and having an extraterrestrial, e.g. Martian origin.)”understand the types or categories of information that How to put the announcement of a putativemay be needed for further validation or dismissal of a discovery of such a weird life on Earth into theclaim. London scale? Shadow biosphere? Not extraterrestrial life, but weird life? Such a discovery certainly would be an important step towards the discovery of 5
  6. 6. extraterrestrial life both theoretically and practically. surface of the Earth) it would probably be easy toTheoretically because it would be a proof that life distinguish between a weird life form and a technicalhaving a different, non terrestrial structure and origin artifact. (Though just in these cases it is very difficultcan exist within the Solar System, or even on Earth. to distinguish terrestrial life and artifact fromPractically because its discovery would be a great help something really weird and alien.) The result of ain the search for extraterrestrial life on other planetary research outside the Solar System is made by remotebodies. sensing (optically, by radio etc.) and no confusion is Convinced by the arguments of Paul Davies it is expected even in the case when we find a biosignatureclear that it might represent a discovery of enormous or a technosignature. In the latter case traces of ascientific importance. But what kind of social or highly advanced technical civilization will bepolitical impact of such an announcement is to be obviously different from a planet with traces of someexpected? Would the world view or religious belief of kind of life on its surface. It does not mean, however,the man in the street change if it will be proved that that an exoplanet, where biosignatures are discovered,some deep-living microbes, remaining trapped in is in want of intelligent life, but we can’t find it if theisolated pockets for eons, might represent a results of its technology are invisible for us.fundamentally different life form? Very probably notin the slightest degree. The media would be interested VII. CONCLUSIONSonly in the problem whether this weird life isextraterrestrial or not. If it is proved that they probably Experts of social sciences should take thewere ever belonging to our biosphere, the impact on structure of the respective scales, as well as the RSI orsociety of such a discovery will disappear at once. LSI values into consideration when investigating in a It means that the announcement of a shadow hypothetical case the possible effects of anbiosphere on Earth represents a case when the announcement of a putative discovery of ET life orscientific value of the event would be very high and its intelligence on science, on world view and on impact very low. Since both the Rio scale and The social impact of such an announcement dependsthe London scale are suggested to quantify the namely critically on the scale value and every kind ofimportance (both for science and for society) of a generalization is misleading. It is improbable that ourputative discovery of traces of extraterrestrial Post Detection Task Group would act in case of antechnology and life respectively, I am inclined to announcement of an ET life discovery (either on theexclude this possibility from the cases listed in the Earth or elsewhere), therefore an independent body ofLondon scale. Accepting that such a discovery (of experts should be organized to prepare a “Declaration”weird life on Earth) would be a very important one, like document for such cases and react as an authoritynevertheless – because of a probable lack of impact to such an announcement. At a recent NASAon media and society – I don’t think that in such a case astrobiology conference near Johnson Space Centerthere would be a need to use a simple, understandable the following statement was declared: “Because theordinal scale in the communication with the media. stakes involved with any announcement of possible orMy opinion is that it would belong to the long list of likely extraterrestrial life are so high – both for scienceimportant discoveries in basic sciences, which are and for the societal and religious implications of suchtreated mainly in science journals, magazines and TV a discovery – the issue brings out very strong feelings.or radio science programs, where mostly well At the conference, a leading cautionary voice ininformed media people comment the event. astrobiology proposed that a special protocol be established to oversee release of any journal articles VI.A COMBINED SCALE FOR LIFE AND making dramatic extraterrestrial claims. Andrew INTELLIGENCE? Steele of the Carnegie Institution for Science in Washington … compared the absence of astrobiology Taking into account the recent convergence of review with the formal procedures set up by scientistsSETI and astrobiology the question arises whether we involved in the search for extraterrestrialneed two scales to quantify the importance of any intelligence…” (Kaufman 2010). I interpret thisdiscovery within the broad range of “search for life warning also as an invitation to prepare a scale, likeand intelligence in the Universe”? Is it possible that the Rio Scale, in case an announcement of thesomebody announces such a discovery and it is discovery of extraterrestrial life is made and there is andubious whether it is intelligent or non-intelligent life? urgent need to communicate it properly to the publicAt present I doubt that such a dilemma might occur. In through the media. This is exactly the purpose of thethe case of a result of a research within the Solar London scale.System (where we mostly use direct investigation byspace probes or just normal field research on the 6
  7. 7. ACKNOWLEDGEMENTS Astronautica in print (DOI: 10.1016/ j.actaastro.2009.07.007)Special thanks are due to Dr. Margaret Race whosehelp has been very useful in constructing the London 3. Almár, I. and Race, M. 2010: Discovery ofScale. Mr. Henrik Hargitai and Mr. Pál Decsy have extraterrestrial life: assessment by scales of itsboth helped to prepare this presentation. Support by importance and associated risk Phil. Trans. R. Soc. ACollegium Budapest (ESA ECS-project No. 98076) is in printgratefully acknowledged. 4. Almár, I. and Shuch H.P. 2007: The San Marino scale: a new analytical tool for assessing transmission REFERENCES risk Acta Astronautica 60 57-591. Davies, P. 2010: The Eerie Silence Allen Lane 5. Kaufman, M. 2010: Washington Post Almár, I. and Tarter, J. 2000: The discovery of ETI article/2010/04/30/AR2010043002000,htmlas a high-consequence low-probability event. Acta 7