Ten thousand revolutions: conjectures about civilizations

Ten thousand years ago, no-one on Earth was living a “civilized” life. What has happened since is remarkable and impossible to fully comprehend; yet, everyone has ideas about civilization, and how the world came to be as it is. Such understandings of civilizations on Earth inevitably influence speculation about extraterrestrial civilizations, in two ways. First, sometimes a specific Earth civilization or historical experience is explicitly used as a basis for inferences about extraterrestrial civilizations. Second, more general assumptions about the development and functioning of Earth's societies shape conjectures about alien societies. This paper focuses on the latter, general assumptions, with the aim of considering how we can use multidisciplinary approaches, and our knowledge of Earth's civilizations, to our best advantage in SETI.     

What should we say to extraterrestrial intelligence?: An analysis of responses to “Earth Speaks”

If scientists engaged in the Search for Extraterrestrial Intelligence (SETI) detect a signal from an extraterrestrial civilization, one of the most pressing issues facing humankind will be “Should we reply, and if so, what should we say?” Building on an infrastructure that the SETI Institute used to gather over 50,000 messages from around the world to send onboard the Kepler mission, Earth Speaks invites people to submit online their text messages, pictures, and sounds, as they ponder what they would want to say to an extraterrestrial civilization. Participants for the study have been recruited from 68 nations, from all walks of life. By tracking demographic variables for each person submitting a message, we have identified commonalities and differences in message content that are related to such factors as age and gender. Similarly, by tracking the date on which messages were submitted and the location from which the message was sent, we have also identified the way in which message content is related to time and geographic location. Furthermore, when we compare previous themes derived from textual messages to our current categorical analysis of submitted images, we find our textual themes to be concurrently validated. In doing so, we find the Earth Speaks Website not only allows for the construction of interstellar messages, but also functions as a projective psychological assessment of species-level human identity. We next proceed to demonstrate the generative power of our method by showing how we can synthesize artificial messages from the Earth Speaks messages. We then discuss how these artificially generated messages can be tailored to represent both commonality and diversity in human thought as it is revealed through our data. We end by discussing our method's utility for cross-disciplinary research in the social sciences and humanities.     

Information theory,animal communication,and the search for extraterrestrial intelligence

We present ongoing research in the application of information theory to animal communication systems with the goal of developing additional detectors and estimators for possible extraterrestrial intelligent signals. Regardless of the species, for intelligence (i.e., complex knowledge) to be transmitted certain rules of information theory must still be obeyed. We demonstrate some preliminary results of applying information theory to socially complex marine mammal species (bottlenose dolphins and humpback whales) as well as arboreal squirrel monkeys, because they almost exclusively rely on vocal signals for their communications, producing signals which can be readily characterized by signal analysis. Metrics such as Zipf's Law and higher-order information-entropic structure are emerging as indicators of the communicative complexity characteristic of an “intelligent message” content within these animals’ signals, perhaps not surprising given these species’ social complexity. In addition to human languages, for comparison we also apply these metrics to pulsar signals—perhaps (arguably) the most “organized” of stellar systems—as an example of astrophysical systems that would have to be distinguished from an extraterrestrial intelligence message by such information theoretic filters. We also look at a message transmitted from Earth (Arecibo Observatory) that contains a lot of meaning but little information in the mathematical sense we define it here. We conclude that the study of non-human communication systems on our own planet can make a valuable contribution to the detection of extraterrestrial intelligence by providing quantitative general measures of communicative complexity. Studying the complex communication systems of other intelligent species on our own planet may also be one of the best ways to deprovincialize our thinking about extraterrestrial communication systems in general.     

The benefits and harm of transmitting into space

Deliberate and unintentional radio transmissions from Earth propagate into space. These transmissions could be detected by extraterrestrial watchers over interstellar distances. This article analyzes the harm and benefits of deliberate and unintentional transmissions relevant to Earth and humanity. Comparing the magnitude of deliberate radio broadcasts intended for messaging to extraterrestrial intelligence (METI) with the background radio spectrum of Earth, we find that METI attempts to date have much lower detectability than emissions from current radio communication technologies on Earth. METI broadcasts are usually transient and several orders of magnitude less powerful than other terrestrial sources, such as astronomical and military radars, which provide the strongest detectable signals. The benefits of radio communication on Earth most probably outweigh the potential harm of detection by extraterrestrial watchers; however, the uncertainty regarding the outcome of contact with extraterrestrial beings creates difficulty in assessing whether or not to engage in long-term and large-scale METI.     

Synchronized SETI-the case for "opposition"

If the signals being sought in search for extraterrestrial intelligence (SETI) programs exist but are brief (for example, they are produced intermittently to conserve energy), then it is essential to know when these signals will arrive at the Earth. Different types of transmitter/receiver synchronization schemes are possible, which vary in the relative amount of effort required by the transmitter and the receiver. The case is made for a scheme that is extremely simple for the receiver: Make observations of a target when it is at maximum angular distance from the Sun (i.e., "opposition"). This strategy requires that the transmitter has accurate knowledge of the distance and proper motion of the Sun and the orbit of the Earth. It is anticipated that within the next 10-20 years it will be possible to detect directly nearby extrasolar planets of approximately terrestrial mass. Since extraterrestrial transmitters are expected to have significantly more advanced technology, it is not unreasonable to expect that they would be able to detect the presence of the Earth and measure its orbit at even greater distances. This strategy is simple to implement, and opposition is also typically the time when observations are easiest to make. Limited opposition surveys contained in a number of all-sky surveys have already been performed. However, full-sky opposition surveys are best suited to detectors with very large fields of view.     

Energy cycling and hypothetical organisms in Europa's ocean

While Europa has emerged as a leading candidate for harboring extraterrestrial life, the apparent lack of a source of free energy for sustaining living systems has been argued. In this theoretical analysis, we have quantified the amount of energy that could in principle be obtained from chemical cycling, heat, osmotic gradients, kinetic motion, magnetic fields, and gravity in Europa's subsurface ocean. Using reasonable assumptions based on known organisms on Earth, our calculations suggest that chemical oxidation-reduction cycles in Europa's subsurface ocean could support life. Osmotic and thermal gradients, as well as the kinetic energy of convection currents, also represent plausible alternative sources of energy for living systems at Europa. Organisms thriving on these gradients could interact with each other to form the complex energy cycling necessary for establishing a stable ecosystem.     

Earth observation from space – The issue of environmental sustainability

Remote sensing scientists work under assumptions that should not be taken for granted and should, therefore, be challenged. These assumptions include the following:1. Space, especially Low Earth Orbit (LEO), will always be available to governmental and commercial space entities that launch Earth remote sensing missions.2. Space launches are benign with respect to environmental impacts.3. Minimization of Type 1 error, which provides increased confidence in the experimental outcome, is the best way to assess the significance of environmental change.4. Large-area remote sensing investigations, i.e. national, continental, global studies, are best done from space.5. National space missions should trump international, cooperative space missions to ensure national control and distribution of the data products.At best, all of these points are arguable, and in some cases, they're wrong. Development of observational space systems that are compatible with sustainability principles should be a primary concern when Earth remote sensing space systems are envisioned, designed, and launched. The discussion is based on the hypothesis that reducing the environmental impacts of the data acquisition step, which is at the very beginning of the information stream leading to decision and action, will enhance coherence in the information stream and strengthen the capacity of measurement processes to meet their stated functional goal, i.e. sustainable management of Earth resources. We suggest that unconventional points of view should be adopted and when appropriate, remedial measures considered that could help to reduce the environmental footprint of space remote sensing and of Earth observation and monitoring systems in general. This article discusses these five assumptions in the context of sustainable management of Earth's resources. Taking each assumption in turn, we find the following:(1) Space debris may limit access to Low Earth Orbit over the next decades.(2) Relatively speaking, given that they're rare event, space launches may be benign, but study is merited on upper stratospheric and exospheric layers given the chemical activity associated with rocket combustion by-products.(3) Minimization of Type II error should be considered in situations where minimization of Type I error greatly hampers or precludes our ability to correct the environmental condition being studied.(4) In certain situations, airborne collects may be less expensive and more environmentally benign, and comparative studies should be done to determine which path is wisest.(5) International cooperation and data sharing will reduce instrument and launch costs and mission redundancy. Given fiscal concerns of most of the major space agencies – e.g. NASA, ESA, CNES – it seems prudent to combine resources.     

Reply policy and signal type: assumptions drawn from minimal source information

A scenario is developed under which a discovery of extraterrestrial technology is made by one of the World’s search for exterrestial intelligence (SETI) programs. The nature of the signal received gives an absolute minimum of information as to the nature of the senders. Current SETI detection and reply policy is examined under these assumptions. Current policy calls for prompt and public release of signal information and stellar coordinates upon announcement of a discovery. The SETI protocol calls for no reply until authorized by international consultations. It is argued that changes are needed in these policies to guard against the possibility of unauthorized replies that could severely complicate long-term interstellar communication.     

Instrumentation and vehicle platform of a miniaturized submersible for exploration of terrestrial and extraterrestrial aqueous environments

An example of an extraterrestrial environment likely to support life is the vast liquid body believed to hide underneath the frozen crust of Jupiter's moon Europa. The hypothetical exploration of this, as well as the more accessible subglacial lakes on Earth, has been used as model applications for the development of a heavily miniaturized, yet qualified, submersible with the potential to be deployable either in itself through a long and narrow borehole or as the daughter craft of an ice-penetrating cryobot.Onboard the submersible, which is only 20 cm in length and 5 cm in diameter, accommodation of a versatile set of sensors and instruments capable of characterizing and imaging the surroundings, and even collecting water samples with microorganisms for return, is facilitated through the use of miniaturization technologies. For instance, together with a small camera, a laser-based, microoptic device enables the 3-D reconstruction of imaged objects for topographical measurements. As a complement, when the water is turbid or a longer range is wanted, the world's smallest side-scanning sonar, exhibiting centimeter resolution and a range of over 30 m, has been developed. The work on miniaturizing a CTD, which is a widely employed oceanographic instrument used to measure and correlate conductivity, temperature, and depth, has commenced. Furthermore, a device employing acoustics to trap microscopic particles and organisms, and, by this, enrich water samples, is under development. To ensure that the gathered samples are pristine until analyzed at the end of a mission, the device is equipped with high-pressure, latchable valves.Remote operation and transfer of measurement data and images, or even live streaming of video, is made possible through a kilometer-long fiber optic cable being reeled out from the vehicle underway and tethering it to a terminal. To extend the missions, the same fiber shall also be capable of charging the onboard batteries.In this paper, the vehicle and its subsystems are summarized. Subsystems essential for the vehicle's operation, e.g., hull structure, communication and power management, are treated separately from those of more mission-specific nature, like the instruments mentioned above.     

Searching for alien artifacts on the moon

The Search for Extraterrestrial Intelligence (SETI) has a low probability of success, but it would have a high impact if successful. Therefore it makes sense to widen the search as much as possible within the confines of the modest budget and limited resources currently available. To date, SETI has been dominated by the paradigm of seeking deliberately beamed radio messages.However, indirect evidence for extraterrestrial intelligence could come from any incontrovertible signatures of non-human technology. Existing searchable databases from astronomy, biology, earth and planetary sciences all offer low-cost opportunities to seek a footprint of extraterrestrial technology. In this paper we take as a case study one particular new and rapidly-expanding database: the photographic mapping of the Moon's surface by the Lunar Reconnaissance Orbiter (LRO) to 0.5 m resolution. Although there is only a tiny probability that alien technology would have left traces on the moon in the form of an artifact or surface modification of lunar features, this location has the virtue of being close, and of preserving traces for an immense duration.Systematic scrutiny of the LRO photographic images is being routinely conducted anyway for planetary science purposes, and this program could readily be expanded and outsourced at little extra cost to accommodate SETI goals, after the fashion of the SETI@home and Galaxy Zoo projects.     

Positive consequences of SETI before detection

Even before a signal is detected, six positive consequences will result from the scientific search for extraterrestrial intelligence, usually called SETI. (1) Humanity’s self-image: SETI has enlarged our view of ourselves and enhanced our sense of meaning. Increasingly, we feel a kinship with the civilizations whose signals we are trying to detect. (2) A fresh perspective: SETI forces us to think about how extraterrestrials might perceive us. This gives us a fresh perspective on our society’s values, priorities, laws and foibles. (3) Questions: SETI is stimulating thought and discussion about several fundamental questions. (4) Education: some broad-gage educational programs have already been centered around SETI. (5) Tangible spin-offs: in addition to providing jobs for some people, SETI provides various spin-offs, such as search methods, computer software, data, and international scientific cooperation. (6) Future scenarios: SETI will increasingly stimulate us to think carefully about possible detection scenarios and their consequences, about our reply, and generally about the role of extraterrestrial communication in our long-term future. Such thinking leads, in turn, to fresh perspectives on the SETI enterprise itself.     

The lure of local SETI: Fifty years of field experiments

With the commemoration in October 2007 of the Sputnik launch, space exploration celebrated its 50th anniversary. Despite impressive technological and scientific achievements the fascination for space has weakened during the last decades. One contributing factor has been the gradual disappearance of mankind's hope of discovering extraterrestrial life within its close neighbourhood. In striking contrast and since the middle of the 20th century, a non-negligible proportion of the population have already concluded that intelligent beings from other worlds do exist and visit Earth through space vehicles popularly called Unidentified Flying Objects (UFOs). In light of the continuous public interest for the UFO enigma symbolized by the recent widely diffused media announcements on the release of French and English governmental files; and considering the approach of broadening the strategies of the “Active SETI” approach and the existence of a rich multi-disciplinary UFO documentation of potential interest for SETI; this paper describes some past scientific attempts to demonstrate the physical reality of the phenomena and potentially the presence on Earth of probes of extraterrestrial origin. Details of the different instrumented field studies deployed by scientists and organizations during the period 1950–1990 in the USA, Canada and Europe are provided. In conclusion it will be argued that while continuing the current radio/optical SETI searches, there is the necessity to maintain sustaining attention to the topic of anomalous aerospace phenomena and to develop new rigorous research approaches.     

Global partnerships: Expanding the frontiers of space exploration education

Globalization is creating an interdependent space-faring world and new opportunities for international partnerships that strengthen space knowledge development and transfer. These opportunities have been codified in the Global Exploration Strategy, which endorses the “inspirational and educational value of space exploration” [1]. Also, during the 2010 Heads of Space Agencies Summit celebrating the International Academy of Astronautics’ (IAA) 50th Anniversary, space-faring nations from across the globe issued a collective call in support of robust international partnerships to expand the frontiers of space exploration and generate knowledge for improving life on Earth [2].Educators play a unique role in this mission, developing strategic partnerships and sharing best educational practices to (1) further global understanding of the benefits of space exploration for life on Earth and (2) prepare the next generation of scientists required for the 21st Century space workforce. Educational Outreach (EO) programs use evidence-based, measurable outcomes strategies and cutting edge information technologies to transfer space-based science, technology, engineering and mathematics (STEM) knowledge to new audiences; create indigenous materials with cultural resonance for emerging space societies; support teacher professional development; and contribute to workforce development initiatives that inspire and prepare new cohorts of students for space exploration careers. The National Space Biomedical Research Institute (NSBRI), the National Aeronautics and Space Administration (NASA) and Morehouse School of Medicine (MSM) have sustained a 13-year space science education partnership dedicated to these objectives.This paper briefly describes the design and achievements of NSBRI's educational programs, with special emphasis on those initiatives' involvement with IAA and the International Astronautical Congress (IAC). The IAA Commission 2 Draft Report, Space for Africa, is discussed as a model for developing sustainable partnerships and indigenous programs that support Africa's steady emergence as a global space-faring force. The IAC will provide timely: 2011 South Africa will provide timely feedback to refine that report's strategies for space life sciences education and public engagement in Africa and around the globe.     

Metalaw and relations with intelligent beings revisited

A body of Metalaw must be recognized or established in order to anticipate the discovery of an incident of intelligent life indigenous to a place or dimension outside the realm and comprehension of extraterrestrial intelligence (ETI) as understood on the planet Earth. It has been said that the limits of your language are the limits of your world. Recognition of life and communication between intelligent beings is and will be the determining factor in humankind's world of the future. But what is the correct language to use in the search for ETI? Philosophical, legal and sociological realities will govern our future as beings of the universe and beyond. This is a study which must be pursued and perfected to the extent of our abilities prior to the immediacy of our need. Such study was begun many years ago by the best of our scholars but their activities are not well known today. In arguing for the need to proceed with our evolving discoveries of realities and possibilities, this article also brings to light the earlier work of jurists and philosophers on relationships with ETI.     

Assuring the sustainability of space activities

The growth of new space systems and the continued creation of orbital debris could in a few years make activities in Earth orbit unsustainable, so finding cost-effective ways to sustain space activities in Earth orbit is essential. Because outer space activities serve the needs of the military–intelligence, civil, and commercial communities, each with their own requirements, creating the necessary international agreements for reaching and maintaining a condition of sustainability will not be easy. This paper summarizes the primary issues for the international space community regarding our future ability to reap the benefit of space systems in Earth orbit. It explores several of the efforts to develop international agreements that would lead to or support the sustainability of space activities and examines the benefits and drawbacks of each approach. In particular, it reviews progress within the UN COPUOS, and examines the EU's proposal for an international Code of Conduct for Outer Space Activities. It also notes the need for states to establish or expand their own space legal infrastructure to conform to the UN treaties and guidelines for space activities.     

Avoiding collisions: the Spaceguard Foundation

The Earth has a long and violent history of collisions with extraterrestrial bodies such as asteroids and comet nuclei. Several of these impacts have been large enough to produce major environmental changes, causing mass extinctions and severe alterations to weather patterns and geography. There is no reason to suppose that the likelihood of such collisions will be any less in the future and the spread of human settlement, civilisation, and particularly urbanisation, makes it much more likely that a future impact, even relatively small, could result in the massive loss of human life and property. Despite the fact that the technology exists to predict and to some extent prevent such events, there is currently no co-ordinated international response to this threat. This article presents a realistic assessment of the threat to Earth from NEOs, describes the (underfunded) efforts so far made to counter it and makes a plea for further action to produce a fully functioning Spaceguard Foundation.     

Asymmetry in Active SETI: A case for transmissions from Earth

The Search for Extraterrestrial Intelligence (SETI) typically presupposes contact with extraterrestrial civilizations much longer lived than humanity. Many have argued that given humanity's “youth,” the burden of transmitting should be placed on the extraterrestrial civilizations, which presumably possess more advanced technologies. These assumptions have contributed to the current emphasis on Passive SETI. Complementing this existing stress on Passive SETI with an additional commitment to Active SETI, in which humankind transmits messages to other civilizations, would have several advantages, including (1) addressing the reality that regardless of whether older civilizations should be transmitting, they may not be transmitting; (2) placing the burden of decoding and interpreting messages on advanced extraterrestrials, which may facilitate mutual comprehension; and (3) signaling a move toward an intergenerational model of science with a long-term vision for benefiting other civilizations as well as future generations of humans. Technological requirements for Active SETI are considered, and a case is made for Active SETI as a means for experimentally testing variants of the Zoo Hypothesis. Recommendations are provided for sustaining Passive and Active SETI and the communities that conduct these searches.     

Extraterrestrial environmental impact assessments – A foreseeable prerequisite for wise decisions regarding outer space exploration,research and development

Although existing international instruments such as the Outer Space Treaty and Moon Agreement generally express sentiments for minimizing missions' extraterrestrial environmental impacts, they tend to be limited in scope, vague and generally unenforceable. There is no formal structure for assessing how and to what extent we affect those environments, no opportunity for public participation, no uniform protocol for documenting and registering the effects of our actions and no requirement to mitigate adverse impacts or take them into consideration in the decision-making process. Except for precautions limiting forward biological contamination and issues related to Earth satellites, environmental impact analysis, when done at all, remains focused on how missions affect the Earth and near-Earth environments, not how our actions affect the Moon, Mars, Europa, comets and other potential destinations. Extraterrestrial environmental impacts are potentially counterproductive to future space exploration, exploitation and scientific investigations. Clear, consistent and effective international protocols guiding a process for assessing such impacts are warranted. While instruments such as the US National Environmental Policy Act provide legally tested and efficient regulatory models that can guide impact assessment here on Earth, statutory legal frameworks may not work as well in the international environment of outer space. A proposal for industry-driven standards and an environmental code of conduct based, in part, on best management practices are offered for consideration.