espi_perspectives_43 13 January 2011. Issue 43 of the "ESPI Perspectives" series examines the scientific and sociological background of the search for extraterrestrial intelligent life.


The search for extraterrestrial life has fascinated scientists and the public alike for over half a century. In recent years, astronomers and planetary scientists have multiplied their efforts to discover life forms by probing planets suitable for supporting its development with telescopes and robotic exploration missions. Although the probability of discovering micro-organisms on other planets is increasing, the prospect of making contact with developed, intelligent extraterrestrial beings remains distant. However, such an event can not be excluded; it may happen unexpectedly and under as yet unforeseen circumstances, but it remains in the realm of possibility. In fact, recent opinion polls have shown that a large part of the public considers such an event as very probable, or that it has even taken place already. Although the popularised perception of such “close encounters of the third kind” in the form of UFO sightings is scientifically unfounded, it helps to build public support for space exploration missions, advance scientific knowledge on atmospheric phenomena and psychologically prepare the public for encountering extraterrestrial life. Furthermore, one should not necessarily assume that such a contact would be initiated by humans, or that we would be able to realise and comprehend it based on our own experience and intellect. After all, it would be the greatest discovery in the history of mankind.

Philippe Ailleris, founder of the UAP Observations Reporting Scheme and author of ESPI Perspectives 43


Philippe Ailleris is a Project Controller at the Space Research and Technology Centre of the European Space Agency (*), in the Netherlands. His childhood fascination with astronomy and space exploration led to his current employment in the space sector and interests in exobiology and Unidentified Aerial Phenomena (UAP). Despite the controversy surrounding UAP, he approaches the topic from a professional, rational and scientific perspective and believes that there is a need to keep an attitude of humility and scientific open-mindedness, since some UAP reports might represent events worthy of research. Rare atmospheric events, near-earth space phenomena, unexpected consequences of human activity (radio signals, space debris and pollution), social, cultural and psychological phenomena, or interactions among these may be revealed by the further study of UAP cases. In 2009 he founded and currently leads the UAP Observations Reporting Scheme Project (, which he initiated under the framework of the 2009 International Year of Astronomy. The Project, presented at the European Planetary Science Congress 2009 in Potsdam, Germany, is aimed at astronomers, providing a venue for reporting unexplained sightings and containing resource pages documenting possible explanations for those sightings. His most recent publication is “The Lure of Local SETI: Fifty Years of Field Experiments” for Acta Astronautica, the journal of the International Academy of Astronautics (2010), which was based on an earlier presentation at UNESCO in Paris.

(* Any views expressed in this ESPI Perspectives issue are entirely his own and not those of the European Space Agency)

- ESPI Perspectives 43: “UFOs and Exogenous Intelligence Encounters”. 











photo credits: ESPI

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