More than six decades after the first experimental searches began, humanity continues to develop new strategies for discovering life beyond Earth — seeking to understand our place in the cosmos and to answer one of the most profound scientific questions: Are we alone?

Today, this pursuit extends far beyond simply pointing a radio telescope at the sky. It encompasses the design of advanced digital backends, the implementation of rapid data-analysis algorithms, and the integration of cutting-edge hardware capable of processing massive data streams in real time. Modern SETI systems now rely on high-speed Ethernet packet architectures, real-time calibration frameworks, and open-source search algorithms that enable reproducible and scalable experimentation.

Through the collaborative efforts of the Breakthrough Listen program and the SETI Institute, our search has evolved from searching for narrowband signals over limited frequency ranges to expansive surveys covering up to 50 GHz, capable of identifying both broadband and modulated signals. With some experiments producing over 50 TB of data each week, autonomous post-processing pipelines have become essential for data triage, candidate verification, and continuous discovery.

In this talk, I will present a modern view of the search for technosignatures and describe how contemporary hardware, distributed computing, and intelligent algorithms are reshaping the future of SETI.

How to cite: Tremblay, C.: Searching the Radio Sky: Present and Future Experiments in Technosignature Science, Europlanet Science Congress 2026, The Hague, The Netherlands, 6–11 Sep 2026, EPSC2026-275, https://doi.org/10.5194/epsc2026-275, 2026.

The search for extraterrestrial intelligence (SETI) has traditionally focused on detecting powerful, narrowband electromagnetic beacons. However, terrestrial technology is increasingly evolving toward low-power, distributed, wideband digital infrastructure. The strict adherence to narrowband filtering that characterises most SETI surveys, risks discarding the aggregate leakage signatures of advanced civilisations by systematically misclassifying them as unstructured noise. We investigate the feasibility of detecting such planetary-scale broadband radio technosignatures (BRaTs) using a hierarchical observational framework. In this tiered approach, wide-field radio surveys conducted by next-generation arrays (such as the SKA and its precursors) perform the initial deep-field observations, with targeted Very Long Baseline Interferometry (VLBI) providing high-resolution follow-up. Because broadband continuum emission is largely insensitive to Doppler drift, long-duration "SETI Deep Fields'' are observationally viable, extending the accessible detection volume for Kardashev Type I leakage to ~100 pc. To distinguish these signals from other astrophysical confounders (of which there are many!), a multi-wavelength, multi-parameter diagnostic framework is presented. Candidate technosignatures are identified through a convergence of high brightness temperatures, negligible circular polarisation, spectral non-uniformity, interstellar scintillation, and (probable) sub-milliarcsecond astrometric co-motion with nearby Galactic stars/exoplanets.

How to cite: Garrett, M.: Identifying Broadband Radio Technosignatures (BRATS) in deep, wide-field radio surveys.  , Europlanet Science Congress 2026, The Hague, The Netherlands, 6–11 Sep 2026, EPSC2026-133, https://doi.org/10.5194/epsc2026-133, 2026.

How to cite: Henrique Salvan, A. and Strom, C.: Surface Technosignatures: Searching for Signs of Artificial Patterning on Extraterrestrial Terrain, Europlanet Science Congress 2026, The Hague, The Netherlands, 6–11 Sep 2026, EPSC2026-690, https://doi.org/10.5194/epsc2026-690, 2026.

When people hear the word “alien,” they often imagine little green men: humanoid beings with oversized heads, antennae, flying saucers, and ray guns. These familiar science-fiction tropes have become a form of cultural shorthand for extraterrestrial life. As scholars of science fiction and popular culture have noted, alien imagery is deeply shaped by inherited visual and narrative conventions that reflect human anxieties, fantasies, and social structures. Rather than imagining truly unfamiliar forms of life, popular depictions of aliens frequently reproduce anthropocentric assumptions and recognizable human characteristics.

At the same time, planetary science and astrobiology are rapidly expanding our understanding of the diversity of planetary environments that exist beyond Earth. Thousands of exoplanets have now been identified, revealing worlds with conditions radically unlike those found in our solar system. As scientific knowledge of planetary systems expands, so too does the challenge of imagining what forms of life might emerge under such unfamiliar conditions. SETI and astrobiology therefore confront not only technical and scientific questions, but also conceptual and imaginative ones.

In this context, imagination is not opposed to science. It is a necessary component of frontier science. Scientists routinely engage in speculative modelling when theorizing about planetary habitability, technosignatures, or forms of life that may differ fundamentally from terrestrial biology. Exoplanets themselves were imagined long before they were directly observed. Yet despite this speculative dimension, human conceptions of extraterrestrial life often remain constrained by inherited cultural imagery and anthropocentric assumptions.

Philosopher Thomas Nagel famously argued that humans cannot fully access the subjective experience of another species, raising questions about how we might recognize or even conceptualize genuinely alien forms of consciousness. Similarly, contemporary astrobiology researchers such as Sarah Walker have suggested that because we still lack a complete definition of life itself, we may not know what we are searching for, or whether we would recognize alien life if encountered. The challenge, therefore, is not simply detecting extraterrestrial life, but imagining possibilities that exceed existing conceptual frameworks.

This presentation proposes that artistic practice can help expand the conceptual and imaginative frameworks through which extraterrestrial life is envisioned. Art-science convergence creates opportunities for speculative inquiry that challenge inherited assumptions, surface hidden biases, and generate alternative ways of thinking about life beyond Earth.

The presentation draws on the concept of enabling constraints, developed within complexity theory and creativity studies. Enabling constraints are structures that narrow possibilities in productive ways, encouraging novelty and emergent thinking rather than restricting creativity. In the context of art-science collaboration, scientific knowledge can function as an enabling constraint by grounding imaginative exploration within plausible scientific conditions. Rather than limiting creativity, scientific parameters can generate more inventive and conceptually sophisticated responses by pushing participants beyond familiar cultural clichés. Scientific knowledge, therefore, becomes a catalyst for imagination rather than a constraint upon it.

This framework is explored through several examples of transdisciplinary artistic practice connected to SETI and astrobiology. The SETI Institute’s Artist in Residence (AIR) program connects artists with researchers working in astronomy, planetary science, astrobiology, and SETI. The program supports artists whose work reflects on questions surrounding the origins of life, the evolution of intelligence, and humanity’s place in the cosmos. As SETI researcher Jill Tarter has noted, the search for extraterrestrial intelligence requires us to “conceive of something that we can’t yet conceive.” Artistic practice can provide tools for engaging with this challenge.

One example is Daniela de Paulis’ project A Sign in Space, developed in collaboration with the European Space Agency, the SETI Institute, and multiple radio observatories. The project staged a speculative scenario in which humanity received a simulated extraterrestrial message transmitted from Mars orbit. Participants around the world collaborated to decode the signal, transforming the project into a large-scale experiment in collective interpretation and public participation. Combining scientific infrastructure with participatory artistic practice, the work explored how humans might emotionally, culturally, and intellectually respond to first contact with extraterrestrial intelligence.

Another example is Codex Virtualis by the artist collective Interspecifics, which used machine learning systems trained on images of extremophiles and microbial life to generate speculative alien organisms and taxonomies. By combining astrobiology, artificial intelligence, and artistic experimentation, the project questioned conventional definitions of life while imagining biological systems that diverge from familiar terrestrial forms.

The presentation also draws on my own research project, Imagine Aliens, a transdisciplinary art-science curriculum developed with students ages 6 to 13 in Montreal schools. Students designed alien worlds and extraterrestrial organisms while engaging with scientific information about exoplanets, planetary environments, and astrobiology. Analysis revealed that students’ initial ideas were strongly shaped by popular culture and science-fiction tropes. However, when scientific prompts and constraints were introduced through a custom website and prompt-card system, students moved beyond familiar depictions and developed more varied, imaginative, and scientifically grounded concepts of alien life.

An iteration of the project was later adapted into a public participatory exhibit at the Exploratorium science museum in San Francisco. Museum visitors used exoplanet prompts and speculative biology cards to create drawings of extraterrestrial organisms that departed from conventional “little green man” imagery. In both educational and museum contexts, science functioned not as a limitation on creativity but as an enabling constraint that expanded imaginative possibilities.

Rather than simply correcting inaccurate public perceptions of aliens, these projects offer alternative imaginative frameworks through which extraterrestrial life can be conceived. Art-science convergence expands conceptual repertoires, complicates anthropocentric assumptions, and creates experiential forms of engagement with scientific questions. Artistic practice can therefore function as a legitimate mode of speculative inquiry within SETI and astrobiology, helping both scientists and the public imagine forms of life beyond familiar cultural templates.

How to cite: Forget, B.: Beyond Little Green Men: Reimagining Alien Life Through Art and Science, Europlanet Science Congress 2026, The Hague, The Netherlands, 6–11 Sep 2026, EPSC2026-682, https://doi.org/10.5194/epsc2026-682, 2026.

For several years, the Italian National Institute for Astrophysics (INAF) has been systematically consolidating its outreach and educational activities around the Search for Extraterrestrial Intelligence (SETI), with the explicit goal of connecting high-profile international research programs with broader public engagement on the theme of life in the universe. Italy's contribution to contemporary SETI research is substantial: both the Medicina Radio Observatory and, most notably, the Sardinia Radio Telescope (SRT) participate in the Breakthrough Listen program. The SRT, equipped with a 64-meter dish, currently serves as a primary asset in the global search for technosignatures, conducting observations of targets identified by NASA's TESS mission and of the Galactic Center.

Within this framework, INAF launched the national school competition C'è posta per E.T. (A Message for E.T.), now in its second edition for the 2025–2026 academic year. The initiative exemplifies an Active SETI pedagogical approach: students are tasked with designing a message intended for a hypothetical extraterrestrial civilization, following the legacy of the 1974 Arecibo Message. The competition is deliberately multidisciplinary, engaging students across astrophysics, biology, linguistics, and the social sciences. A central methodological element is the application of computational thinking and coding: participants encode their messages using binary sequences and Pixel Art via Run Length Encoding (RLE), directly mirroring the processes involved in actual interstellar signal synthesis. The impact of this approach was evident during the inaugural edition in 2022, when over 70 school groups participated. Winning messages were transmitted from the ASI Space Geodesy Centre in Matera toward target exoplanets, including TRAPPIST-1 and Kepler-296. The event also incorporated a Moon bounce (Earth-Moon-Earth) experiment, engaging the amateur radio community alongside thousands of students in a coordinated online field trip.

Complementing this school-based initiative is "Tracce di vita" (Tracks of Life), a science communication podcast in Italian language, dedicated to the scientific search for extraterrestrial life. The project fills a gap that had long existed in the Italian science media landscape: no podcast had previously addressed this research domain through a narrative-driven format. Across its episodes, Tracce di vita explores multiple scientific frontiers, including astrochemistry, astrobiology, the history of Mars exploration, exoplanet research, and SETI itself.

The podcast employs a narrative-led format, drawing on interviews with researchers from diverse disciplines — planetologists, biologists, chemists, and historians — to offer an integrated perspective on the search for life. Each episode opens with a historically or culturally situated story: the origins of Fermi's question, Schiaparelli's Martian canals, or the Great Moon Hoax of 1835. This storytelling structure enables listeners to explore both the scientific tools and the deeper motivations behind the research, while foregrounding its historical trajectory and cultural resonance.

By integrating the technical rigor of C'è posta per E.T. with the narrative depth of Tracce di vita, INAF has developed a holistic outreach model. The competition addresses the how of SETI — encoding, transmission, and active signal design — while the podcast investigates the why and the broader historical context, from the Arecibo Message to the Voyager Golden Record. Together, these initiatives offer a replicable framework for the multidisciplinary community, combining scientific communication, interdisciplinary collaboration, and critical reflection.

This approach highlights that science is always tied to its social and historical roots. Instead of treating SETI as a purely technical task, we frame it as a cultural effort to define who we are and what it means to be human. In directing sophisticated instruments toward nearby and distant stars, and in analyzing elusive cosmic radio signals, we are simultaneously engaged in a reflection on human identity. This presentation examines the pedagogical methodology, the technical tools employed, and the outcomes of these initiatives, offering a roadmap for incorporating SETI themes into formal science education and public discourse through digital and narrative innovation.

How to cite: Casu, S., Sandri, M., Gattermeyer Vadilonga, M., and PlayInaf, G.: From Technosignatures to Human Identity: The INAF Strategic Roadmap for SETI Outreach from Schools to the General Public, Europlanet Science Congress 2026, The Hague, The Netherlands, 6–11 Sep 2026, EPSC2026-1159, https://doi.org/10.5194/epsc2026-1159, 2026.

Introduction

In the 20^th century, the increase of knowledge across all (scientific) domains has led to a strong focus on specialisation, a sort of solution to the inability to know everything about many different domains [1]. The increased specialisation has trickled down to the educational offer of universities [2] with increasing possibilities to specialise earlier and to forego fundamental academic skills such as reflection and collaboration.

In this context, astrobiology has been defined as “a timely re-emergence and re-invigoration of ‘natural sciences’”, with focus  on the contemporary question of origin and persistence of life on Earth and other planet.  Here natural sciences are broadly defined as ‘the study of the natural world’ [1]. Because of its intrinsic interdisciplinary nature, astrobiology is a fantastic framework not only to encourage cross-fertilisation among disciplines but also to practice interdisciplinary skills. For these reasons and considering the appeal for the public, it has been proposed that astrobiology is an ideal “subject” for integrating the teaching of science at all levels [3]. In this contribution we present how we, a team of educators and scientists at the University of Amsterdam, have achieved this in the bachelor course “How to design an alien”.

Description

The course has been created and developed by a team of lecturers with specialisation in astrochemistry, exoplanets and planet formation, bio and geo-chemistry, (system) biology, evolution and interdisciplinary teaching. The course combines foundational scientific instruction with collaborative problem-based learning. In the first phase, a series of integrated lectures examines the chemical and physical prerequisites for life, including energy-harvesting reactions,  catalysis, metabolism, information storage, maintenance or replication, and the  complexity, adaptability and limits of terrestrial life. Students investigate the defining characteristics of living systems, the origin of life on Earth, and the diversity of planetary environments both within and beyond the Solar System. Particular emphasis is placed on connecting molecular and biological processes to planetary conditions and astronomical observations.

The second phase consists of an interdisciplinary group project in which students from academic backgrounds ranging from (psycho)biology through chemistry to astrophysics collaboratively chose and investigate a remote planetary environment present in the universe. To push the students to reflect on what collaboration means, a team charter is created where means of communication, responsibilities and expectations, are made explicit [4]. Students are asked to peer-teach disciplinary concepts to one another while jointly constructing  a science-based scenario for a life form  and ecosystem that should be able to maintain itself under the  conditions of their planet of choice. They should prepare a poster and report in which they prove that  the life form they propose meets all the requirements for life discussed in the first phase of the course.  Consultation sessions with the disciplinary experts guide the students and help them solve questions that might arise in the designing process.

The various aliens created by the teams are presented in an end-of-course symposium open to friends, family and faculty staff. During the symposium the teams present posters about their proposed aliens and habitat and are encouraged to sharpen up their ideas by addressing the feedback of the public for the final report on their work. This structure explicitly promotes systems thinking, integrative reasoning, and interdisciplinary communication skills, which are increasingly identified as essential competencies in contemporary science education [5]. Moreover the course turns out to be a highly effective method to teach the various disciplines involved.

References

[1] Cockell, C. (2002). Astrobiology—a new opportunity for interdisciplinary thinking, SPACE POLICY, 18(4), 263-266

[2] Malamud, O. (2010). Breadth versus depth: The timing of specialization in higher education. LABOUR, 24(4), 359–390.

[3] Staley, JT (2003). Astrobiology, the transcendent science: the promise of astrobiology as an integrative approach for science and engineering education and research. CURRENT OPINION IN BIOTECHNOLOGY, 14(3), 347-354

[4] Boor I., Gerritsen D., de Greef L., Rodermans J. (2021). Meaningful assessment in Interdisciplinary Educations, ed. Routledge

[5] Styczinski M.J., Glaser D.M., Hooks M., et al.(2024). Chapter 11: Astrobiology Education, Engagement, and Resources. ASTROBIOLOGY, 24(S1), 216-227.

How to cite: Candian, A., Baeyens, R., Bezaly, O. R., Dalcin Martins, P., Petrignani, A., Vreede, J., Westerhoff, H. V., and van Woerden, N.: How to design an alien: Teaching astrobiology across disciplines at the University of Amsterdam, Europlanet Science Congress 2026, The Hague, The Netherlands, 6–11 Sep 2026, EPSC2026-1081, https://doi.org/10.5194/epsc2026-1081, 2026.

Interstellar messages refer to information and data designed to reach extraterrestrial intelligence through communication technologies employing electromagnetic waves. Since discussions began in the 1960s alongside the search for extraterrestrial intelligence, the principal goal of interstellar message design has been to construct a new linguistic system capable of mediating between extraterrestrial intelligence and humanity. This endeavor has been grounded primarily in mathematical logic and scientific information, as these have been regarded as the only “universal” language and knowledge that humanity and extraterrestrial intelligence might share. By contrast, natural language has been deliberately excluded from the design of interstellar messages because of its vast complexity, dependence on cultural context, and anthropocentric nature.

However, natural language is not only the central means of human communication, but also reflects essential attributes of the human mind, including ways of thinking, identity, culture, and emotion. Moreover, it enables the expression of multidimensional concepts such as “love” in deeply human ways that are difficult to fully convey through mathematical and scientific representation. Therefore, an understanding of human language can serve as a key to a deeper understanding of humanity. Above all, each other's language will inevitably emerge as a fundamental issue in interstellar communication.

Accordingly, this study proposes the design of a new type of interstellar message that enables extraterrestrial intelligence to understand information expressed in natural language, thereby departing from the paradigm based on the language of mathematics and science that has formed the basis of interstellar message design.

First, this study adopts Korean and English as the languages of the message. Korean is the researcher's mother tongue and a regionally confined language, whereas English is the most widely used language in the world. In addition, the two languages form a highly contrastive pair in terms of linguistic structure, including differences in writing system, grammar, and pronunciation. By treating these two languages together, this study seeks to reflect the diversity of natural language, albeit on a limited scale. Furthermore, it considers the possibility of extending the system to other languages rather than confining it solely to these two.

The interstellar message proposed in this study consists of two parts. The first is the primary message. It is expressed in natural language and conveys the content intended for extraterrestrial intelligence. The second is the dictionary. It aids extraterrestrial intelligence in deciphering the primary message by providing information on its vocabulary and grammar. Both parts represent information by arranging characters, symbols, and images on a two-dimensional plane.

The dictionary is composed of a lexical dictionary and a grammatical dictionary. The lexical dictionary explains the meanings of words through one-to-one correspondences between words and images, beginning with concepts that may be commonly understood by both humanity and extraterrestrial intelligence and gradually extending toward terms rooted in human experience and culture. The grammatical dictionary likewise employs correspondences between sentences and images, following a stepwise structure that develops from the simplest sentences to increasingly complex ones.

The primary message is composed from the words and grammar contained in the dictionary, and its content includes the duality of human civilization, the spirit of exploration toward the universe, the emotion of loneliness, the multidimensional nature of love, and the will to connect, thereby seeking to deepen understanding of and empathy for humanity.

In this way, this study suggests the possibility of conveying to extraterrestrial intelligence not only the structural features of human language but also the human qualities implied within it. Furthermore, it explores the potential for interstellar communication in which humanity and extraterrestrial intelligence may achieve deeper understanding of each other through understanding each other's language.

However, despite these efforts, this study also faces the inevitable limitations inherent in any interstellar message. First, there are clear limits to fully representing the complex linguistic systems of Korean and English within the constrained medium of an interstellar message. Moreover, the characteristics of natural language, which have been regarded as obstacles in interstellar message design, remain unresolved. Above all, fundamental questions regarding the cognitive structures and decipherment methods of extraterrestrial intelligence remain unknown, and as long as the existence of extraterrestrial intelligence has not been verified, the assumptions underlying this study necessarily rely on the best inferences.

Perhaps the long-standing aspiration to make the interstellar message itself a complete language mediating between humanity and extraterrestrial intelligence is the fundamental problem that constrains interstellar communication. Rather, exchanging information about each other’s language and sustaining a conversation would be a more suitable way of communication for mutual understanding. Therefore, future interstellar messages must engage with human language at a deeper level.

Conversation is, by nature, a process of repetition and trial and error. Interstellar communication, too, will require the courage to speak first and the patience to teach, to learn, and to sustain dialogue over vast spans of time. If humanity can maintain such courage and patience, then perhaps one day humanity and extraterrestrial intelligence may come to understand each other across the distances between the stars.

How to cite: Won, J.: Designing an Interstellar Message Based on Natural Language, Europlanet Science Congress 2026, The Hague, The Netherlands, 6–11 Sep 2026, EPSC2026-1179, https://doi.org/10.5194/epsc2026-1179, 2026.