Background

In 2004, Abrams & Morrison (Reference Abrams and Morrison2004) surveyed 42 courses on ‘life in the universe’. They found that the courses mainly included the following subjects (Morrison Reference Morrison2002; Brake et al. Reference Brake, Griffiths, Hook and Harris2006):

• • History of the Universe;

• • Formation and History of the Earth;

• • Nature of Life;

• • Evolution of Life;

• • Extraterrestrial Life;

• • Life in Extreme Environments;

• • Life in Our Solar System (Mars and Europa);

• • Aliens, Science Fiction and the Search for Extraterrestrial Intelligence (SETI);

• • The Future of Humankind in the Universe.

An informal survey conducted in 2006 revealed that most ‘extraterrestrial courses’ were pure science courses, where the Drake Equation is used as an organizational tool in order to teach ‘introduction to biology’, ‘introduction to chemistry’, ‘introduction to astronomy’ courses; only a few of the courses concentrated on the history of the idea of extraterrestrial life; and courses rarely debated the science fiction imagination and the UFO myth. Even when these topics appeared in the syllabus, they were placed at the end of the course leaving no time to cover them in depth.

It was decided that a ‘perfect course’ would be one that tried to incorporate all of these subjects, under the umbrella of critical thinking.

Also, the subject of astrobiology is the perfect hook to attract people to study science, the ongoing scientific process, the nature of science and the interdisciplinary aspect of science, while erasing some science misconceptions on the way (Oliveira Reference Oliveira2008).

Understanding the nature of science is very important to science literacy (AAAS 1989; Matthews Reference Matthews1994; McComas & Olson Reference McComas, Olson and McComas1998; NRC 1996; NSTA 2003). McComas et al. (Reference McComas, Clough and Almazroa1998) argue that knowledge of how science works enhances students' understanding of science as a human endeavour, increases interest in science and science classes, improves student learning of science content and promotes better social decision-making (Olson et al. Reference Olson, Clough, Vanderlinden and Kruse2008). As Driver et al. (Reference Driver, Leach, Millar and Scott1996) emphasize that ‘understanding of the nature of science is necessary if people are to make sense of the science and manage the technological objects and processes they encounter in everyday life … [and] make sense of socio-scientific issues and participate in the decision-making process’. Students should learn to understand the purpose of science, the general assumptions underlying scientific knowledge, and the interplay of science, culture and society influencing the development of scientific knowledge (Lederman et al. Reference Lederman, Abd-El-Khalick, Bell and Schwartz2002; Kremer et al. Reference Kremer, Urhahne and Mayer2008). Shamos (Reference Shamos1995) even claims that understanding the nature of science is the key knowledge that citizens use when assessing public issues involving science and technology (Olson et al. Reference Olson, Clough, Vanderlinden and Kruse2008). Thus, it is very important that the nature of science is embedded into a science course for non-science majors.

In addition, people already believe and are fascinated by alien life, thus students will be inherently motivated, curious and engaged in this course (Slater Reference Slater2006; Sullivan & Morrison Reference Sullivan and Morrison2008).

On top of all this, our course ingrains the four principles within the NASA Astrobiology Roadmap (Des Marais et al. Reference Des Marais2003): integrating scientific principles, planetary protection, astrobiology and society, and future generations (Morrison Reference Morrison2001; Brake & Griffiths Reference Brake and Griffiths2004b).

Syllabus

The course has four sections. At the end of each section, there is an exam to evaluate student's knowledge of the material covered.

The four main themes of this upper-division astrobiology course are: the History of the idea of Extraterrestrial Life, the Drake Equation, Scientific Speculation and Science Fiction.

The course starts with a historical perspective to understand how the idea of extraterrestrial life originated and evolved. Then, a series of factors, important in determining whether extraterrestrial life is possible, are examined. Next, the course focuses on the ‘search for aliens’ and ‘trying to contact them’, and the question of whether Earth has been visited by extraterrestrials is approached critically. Finally, the course discusses the importance of science fiction in society and its impact on the current extraterrestrial life framework.

The first section is about History. The lectures have the following themes: Ancient Concepts of Plurality; The Copernican Revolution; The Sidereal Revolution; and Canals on Mars.

The second section is about Science. The lectures have the titles: Drake Equation; Star Formation; Extrasolar Planets and Habitable Planets; Origin and Evolution of Life on Earth; Origin of Intelligence; Human Evolution; Cultural Evolution; Lifetime of Communicable Civilizations; and Evaluating the Drake Equation.

The third section allows for Scientific Speculation, under the subjects: Fermi Paradox; Life in our Solar System; SETI program; Interstellar Travel; and UFOs.

The fourth section is devoted to Science Fiction: What is Science Fiction; Themes and Messages in Science Fiction; History of Science Fiction; the movie and the novel Contact; the novel Hitchhiker's Guide to the Galaxy; the novel Childhood's End; the novel Black Cloud; the Star Wars movies; the Star Trek series; and many other Current Science Fiction works that use Extraterrestrials.

Assessment

It was decided that a multiple criteria grading system is the fairest and least stressful for these students (Rubadeau & Rubadeau Reference Rubadeau and Rubadeau1983). It allows students to work mainly on their own, having control of their progress and to think about the topics instead of memorizing facts (Prather & Slater Reference Prather and Slater2002). Thus, throughout the course, students are required to complete four exams with take-home essays, one essay reviewing a science fiction novel, one project integrating astrobiology with their major area of study, one presentation, an oral examination and 10 homework assignments where students have to critically discuss different astrobiology issues. Self-reflecting essays and critical thinking are major characteristics of the course. In addition, students must also attend classes and actively participate in them. An ongoing, continuous, gradual assessment of the students is conducted.

History

The course begins with the History section. The goal of the first part of the course is to provide a historical and cultural context on the idea of extraterrestrial life. The objective is to make students realize the differences between scientific arguments and other arguments from other areas of society. One of the main goals is that students obtain a better understanding of science. It is expected that, by performing a critical analysis of the past, students will be able to make parallels with the present and thus have a better understanding of the world that surrounds us. Another main goal is that students understand that throughout history, the arguments were not really about aliens, but about what humans wanted.

One of the goals of this section, as well as other sections, is for students to understand the nature of science: science evolves as a tentative, dynamic, ongoing process, science is empirical, science is subjective, science is partly creative and imaginative human endeavour, science is socially and culturally embedded (Lederman et al. Reference Lederman, Abd-El-Khalick, Bell and Schwartz2002). In this section of the course, students study more than 100 individuals throughout history.

The mandatory reading for this section is Michael J. Crowe's Reference Crowe1986 book The Extraterrestrial Debate 1750–1900.

Arguably, the ideology regarding intelligent beings outside Earth started several millennia ago with creation myths (Dick Reference Dick1998). It showed god-like all-powerful extraterrestrial beings, who supposedly created life on Earth and who continued thereafter to be very interested in Earth and on influencing the daily life of humans. These humanoid gods were in all aspects like humans, with the same forms, characteristics, psychology, attitudes, behaviours, etc., except that they had more power (Grinspoon Reference Grinspoon2003). Humans created these extraterrestrial gods in order to explain the gaps in understanding the world.

In the 4th century BC, Plato and Aristotle adopted this geocentric cosmos (Koestler Reference Koestler1959) where a God (‘Prime Mover’) would be constantly looking at us from above. With Earth at the centre of the Universe, humans are the great beneficiaries. This orthodox view is all about humans; humans wanted to be the most important and interesting piece of the Universe, and thus they put themselves at the centre, even if only psychologically (Brake Reference Brake2006).

In 1277, theologians such as the bishop of Paris, Etienne Tempier, decided to condemn those who would say that God could only make one world (Dick Reference Dick1982; Hennessey Reference Hennessey1999), because that would be limiting God's power. From that time on, other worlds and their possible life became the subject of debates.

In the 15th century, Nicholas of Cusa, a Cardinal of the Catholic Church, was among the first to speak about extraterrestrial life; although many had already considered a plurality of worlds (Sagan and Shklovskii Reference Sagan and Shklovskii1966). He thought that extraterrestrial inhabitants are rational beings of a different rank than the men from Earth; for instance, while on Earth humans are ‘gross and material’ (Crowe Reference Crowe1986), the inhabitants of the Sun are bright, enlightened and spiritual. One may think that this is a very anthropocentric view, however that was not the idea of Cardinal Nicholas. For him, Man was the measure of all beings in the Universe. Man was the ‘pinnacle of Creation’ (Crowe Reference Crowe1986), and thus all the other beings only existed in relation to humans. Not only that, but aliens basically had the same characteristics as humans, just more intensified in certain aspects. This reinforced the message that by and large the Cardinal saw the aliens as another version of humans.

The Renaissance brought new lands on Earth, new people on Earth, new science, new technologies and new ideas concerning the Universe (Ferris Reference Feynman1989). In terms of extraterrestrial beings, the Renaissance brought an apparent increase of diversity among them.

There was also a shift in the arguments. The main arguments are now analogy (‘if Earth is a planet, then planets are Earths’) (Dick Reference Dick1996) and the religious argument (Christ became incarnated on Earth, thus Earth is still special).

The face of pluralism in this period is Giordano Bruno. He believed in many Suns and many inhabited worlds. Like the Dominican monk Tommaso Campanella, the Reverend John Wilkins, and many others, Bruno used analogy and argued that ‘a plurality of mankinds’ (Crowe Reference Crowe1986) enhanced the glory of God. For him, the inhabitants of other celestial bodies were beings like ourselves.

In the 17th century, Bernard le Bovier de Fontenelle had a tremendous success with his 1686 Entretiens sur la pluralité des mondes (de Fontenelle Reference de Fontenelle1990). In this work, he populated everything except stars. The arguments that he used were the same those used earlier, analogy and religion. Although he considered himself anti-anthropocentric due to the diversity of aliens in his work, the truth is that the characteristics of his aliens are just exaggerated versions of humans, for example: some aliens would use voice, others would use sign language; some aliens would have a six sense, others would lack some sense; some aliens would be black, while others were white; some aliens loved peace, others war; some lived in groups and others in isolation; some eat meat, while others only eat vegetables; some were dwarfs and others giants, etc. Earth was a miniature Solar System where all of the features were concentrated. Thus, in fact, his pluralism was a mask to congratulate humans on Earth. His incredible influential work made new assumptions about the prominent status of Man; Man is the measure of all beings and all of the extraterrestrial beings are basically human.

About the same period, the famous Christiaan Huygens criticized the wild speculations of Fontenelle, while making the assumption that aliens would be like humans: similar bodies, same senses, same moral, same attitudes. In essence, he also celebrates the greatness of mankind by stating that aliens are humans.

During this period, with a few exceptions (namely Cyrano de Bergerac), many other authors populated the planets with aliens that had human characteristics. On the whole, aliens were humans.

With the Enlightenment, new authors appeared, but the underlying premise continued the same. Thomas Wright of Durham and Immanuel Kant believed in a ranking of beings, with a gradation of many levels of perfection: for Wright the most virtuous rational beings are closer to the Sun, while Kant had the opposite hierarchy. Like Cardinal Nicholas of Cusa before them, they believed that Man was the measure of all beings in the Universe: aliens were just another version of humans.

The Reverend Thomas Dick, like Chalmers and others, used pluralism in his sermons to excite and motivate people. His idea about only one religion in the Universe mirrors his idea that on Earth should be only one religion; thus mankind had the ‘right religion’, which should spread throughout the Universe. Moreover, in 1837, he made a cosmic population census, calculating almost 22 trillion intelligent beings in the Universe. His calculations were based on Earth and how humans get together using the population density of England. Essentially, he calculated how many aliens there would be if all aliens were humans and living like humans.

1835 was the year of the Moon hoax. Richard Locke, a New York journalist, made up stories about supposedly discoveries of living plants, animals and rational beings on the Moon. All of these beings were, at heart, the same types of beings that we see on Earth. Even the rational beings, called men-bat, were fundamentally humans with huge bat wings. The readers of the newspaper did not understand the satire, and totally bought that the aliens were basically humans.

A few years later there was a feud between William Whewell and David Brewster. While coming from opposite directions, Whewell rejected pluralism while Brewster embraced it, they both had the motif of not wanting humanity to lose a central significance in the cosmic plan: Whewell wanted God just for humans with no other beings to be taken care by God, while Brewster argued that since Christ redeemed the sins on Earth then Earth and humans were the most important things in the Universe. These religious arguments are very common throughout history, and the psychological reasons behind them are also usually the same: several dozens of people throughout history argued the same way as Whewell and Brewster. Man has a vital place in the Universe. It is all about us, all about humans. The aliens are just sidekicks in a stage clearly made for humans.

By the middle of the 19th century, arguably the best popularizer of all, Camille Flammarion (Guthke Reference Guthke1990), who still greatly influenced the 20th century attitudes to the extraterrestrial idea (Dick Reference Dick1996), proposed a diversity of life in the Universe: some beings would have additional senses, others would have other sexes, others could be immortal, etc. Although in his idea there was no justification for aliens to look like humans, he still thought that all evolution, on any planet, always leads to rational creatures. Thus, for him, although aliens could be diverse, with different forms and characteristics, the fact is that he still thought that the end result of evolution, the pinnacle of Creation, should still be rational beings like humans. All evolution in any planet should lead to rational-alike human beings. Man is still the measure for all beings. It is still all about humans.

Until the 20th century, pluralism was defended, without observational evidence, and based on faulty, non-scientific arguments, such as: Analogy, Religion, Principle of Plenitude, Principle of Mediocrity, Principle of Uniformity, Wrong Interpretations of Observations, Wild speculations, Probabilities, Personal wishes, etc. All of these arguments are based on humans, their wishes, their characteristics. All of these arguments were about us. Although under the extraterrestrial disguise, these arguments expressed only the psychology, science, reasoning, faith and culture of humans.

At the turn of the century, the battle for the planet of war started. Giovanni Schiaparelli, in 1877, mapped the surface of Mars, with several canali: in Italian, it means natural water channels. In USA, it was wrongly translated as canals, artificially constructed paths of water. This incorrect translation led to euphoria in the general population and in the astronomical community, with Flammarion and Lowell at the top of the believers, about an advanced Martian civilization who had built a planetary irrigation system with a complex and highly sophisticated system of canals. These canals were just an optical illusion, fabricated by the human mind. Moreover, this idea of canals being made by an advanced civilization mirrors the human civilization of the time: it was the era of the canals on Earth: Panama, Dortmund, Manchester, including the famous Suez Canal, a modern wonder of the world, opened to navigation in 1869. It was again all about humans. Astronomers were projecting human society onto planet Mars. About this same time, Flammarion proposed that we should communicate with Martians using the telegraph, exactly for the same reason: since we were using the telegraph, then aliens must be using it too. Thus, humans are still the measure of all things.

Overall, throughout history, it is clear that the discussion about aliens does not bring anything new (Hennessey Reference Hennessey1999) and is in reality all about humans. Mostly, the big questions are about Man's place in the universe (Michaud Reference Michaud2007) and Man's place at the eyes of God. Whatever the opinion, the underlying motif was to keep Man as the pinnacle of creation. Humans project their culture, expectations, attitudes and characteristics into aliens. The history of the idea of extraterrestrial life, tells us more about ourselves than about extraterrestrials. Aliens are, in fact, us.

Science

The Science section (Lunine Reference Lunine2005) uses the Drake Equation (N=R*×f _p×n _e×f _l×f _i×f _c×L) as an organizational tool to teach concepts such as the formation of stars, the chemical basis for life, the methods to detect extra-Solar planets, how many of those planets may be habitable, the origin and evolution of life on Earth, alternative ideas for life on other planets, the evolution of intelligence on Earth, the cultural evolution of the human civilization, speculations on alien technology and language, and speculations about the lifetime of alien civilizations.

The goals of this second part are: to increase scientific knowledge, to know the science behind the idea of extraterrestrial life, to learn scientific concepts, theories and speculations, to study life on Earth and extrapolate about life in the rest of the Universe, to better understand the nature of science, and to become aware that aliens are fundamentally human.

The mandatory reading book for this section of the course is Life in the Universe written by Shostak et al. (Reference Shostak, Bennett and Jakosky2003).

After a general view of the Drake Equation, the Big Bang Theory is studied, especially in terms of chemistry, in order to learn how the elements necessary for life came to be. Following that, the Solar Nebula theory is analysed with the aim of understanding how the Solar System, stars, discs around stars and planets, formed; the objective is not just to learn how the different chemical elements formed, but also to learn how many stars and planets could there be in the universe, and their characteristics. After understanding the formation of planets, the history of searching for extra-Solar planets, the current seven most important methods to detect them, the characteristics of the more than 300 extra-Solar planets already discovered, and extrapolate about possible future others are studied. Subsequently, Earth, the habitability of the planets, in our Solar System and elsewhere, the life-friendly stars and the habitability of our Galaxy is examined. Finally, how insignificantly tiny our familiar planet Earth is, in space and in time, is explored.

After the astronomical factors of the Drake Equation, biological aspects are considered.

The next big chapter is about the origin and evolution of life (Gilmour & Sephton Reference Gilmour and Sephton2003). In this section the nature of life is discussed: its requirements, its characteristics, its chemical basis, its basic molecules (its properties and constituents, amino acids, bases, sugars, phosphates, proteins, nucleic acids, RNA, DNA, etc.), the Miller–Urey experiment, the different theories for the formation of life, the vital importance of carbon and water, along with other relevant characteristics (Koerner & LeVay Reference Koerner and LeVay2000). How life evolved on Earth, since its formation until now, with the most important stages being the origin of life, the origin of oxygen, the development of multicellular life and the Cambrian Explosion, is examined. Subsequently, extremophiles are examined: what they are, where they live, which conditions they need and how can we extrapolate the knowledge about them to other planets and which planets (Koerner & LeVay Reference Koerner and LeVay2000).

Although the scientific details of the subject are provided and discussed, the goal of this chapter, like all of the other chapters, is to critically analyse the big picture. Since students are non-science majors and thus will not work in this area, what is important for them to remember is not the ‘boring’ scientific details that they memorize for the test and forget the next day, but the big picture of the science behind it (Grinspoon Reference Grinspoon2003). With this in mind, a lot of time is spent discussing and analysing Carl Sagan's Cosmic Calendar (Sagan Reference Sagan1986), and trying to draw conclusions from it. For instance, students are expected to realize that the evolution of life on Earth shows that: life started very early after the formation of Earth; most of the time, life was bacterial, unicellular organisms; the multicellular organisms that we know best appeared relatively recently; and humans even more recently. In terms of extremophiles, students are expected to recognize that: life is varied, robust, tough and extremely adaptable to hostile conditions; the fact that we find extremophiles on Earth increases the chances of finding life on other planets (Des Marais & Walter Reference Des Marais and Walter1999); but complex life cannot survive in extreme conditions, since it needs moderate and stable conditions to survive; and intelligent life needs even more stable and moderate conditions. Thus, from both the evolution of life and the existence of extremophiles, students should anticipate that the probability of finding unicellular extraterrestrial organisms is high (Aczel Reference Aczel1998; Darling Reference Davidson2001), while the probability of finding multicellular extraterrestrial organisms is small (Ward & Brownlee Reference Ward and Brownlee2000), and finally the probability of finding intelligent extraterrestrial organisms is very tiny (Ward & Brownlee Reference Ward and Brownlee2000). More than memorizing concepts, the goal is to promote critical thinking.

Next, human evolution is discussed, including the evolution of intelligence on Earth. It is observed that most definitions of intelligence reflect our prejudices and bias; again, it is all about us. Nevertheless, some working definitions are examined, we try to quantify intelligence, and students have to come up with their own ranking of species, based on their own definitions. The origins of intelligence and the lack of importance it has on the survival time of the species are discussed. Several studies made with animals on Earth are analysed. The human evolution from Proconsul until Homo Sapiens is critically analysed, along with theories associated with evolution, for example: convergent evolution, parallel evolution, divergent evolution and punctuated equilibrium.

After the biological factors of the Drake Equation, the social and cultural aspects are considered. Here, the concentration on human affairs is even more important. The next factors are almost exclusively about humans.

The next chapter is devoted to cultural evolution, which includes technological and worldview evolution. Studies about the manipulative abilities of other species are examined, including studies about their language. The evolution of information storage in different species is investigated. The technological evolution of humans, from stone tools to the Internet, is observed. Time is spent discussing the benefits and drawbacks of agriculture, analysing some key advances such as oral and written language, and investigating the power of competition in order to evolve. After that, the evolution of the worldview on human societies is studied, including speculation on how other intelligent species may have a different worldview under different planetary conditions, star system conditions and biological conditions.

Finally, the course speculates on the lifetime of communicable civilizations. The Kardashev classification is examined, including a few hypothetical extension levels. The several mass extinctions that occurred on Earth throughout its history are studied and several dozens of factors that may annihilate our technological human civilization are analysed.

By the end of this section, each student has to provide a critical analysis of the Drake Equation as a whole (Michaud Reference Michaud2007) and has to give about 10 arguments for a higher and for a lower number in each of the factors in the Drake Equation. After determining a possible distance to the nearest communicable civilization, students have to calculate the number of two-way communications we could have with those same potential advanced alien civilizations.

It is important that students realize that the current arguments supporting extraterrestrial life have a logic supported by scientific observations; however, in different parts, scientists still use some wishful thinking, and similar faulty arguments also used throughout history (Basalla Reference Basalla2006). It is also important that they recognize that the efforts to look for life out there are based on a reason of ‘life as we know it’; we look for aliens who are very similar to life on Earth. Again, this search tells us more about ourselves than about extraterrestrials: it is all about us.

In past years, while grading the final essays for this section, a pattern was noticed; students were very pessimistic about the idea of finding advanced extraterrestrial life. Thus, the next sections exist to give them a balance, to make them imagine different possibilities, to make them speculate, to expand their minds, to make them more optimistic and to make them dream.

Curiously, a similar recommendation, in terms of imagining different possibilities, was given in a report published by the National Research Council (NRC 2007): it urged NASA and NSF to expand their minds and look for ‘weird life’ (life with an alternative biochemistry, organisms that lack DNA or other molecules found in life as we know it). In addition to encouraging a wider search (not limited just by Earthly ideas), the Committee left a sombre note: when we find extraterrestrial life, we probably will not even recognize it as life.

Scientific speculation

In the third section of the course, different subjects that could be considered scientific speculation are examined (Pickover Reference Pickover1998; Cohen & Stewart Reference Crowe2002). Possibilities are speculated about, although under the limits of science (Feinberg & Shapiro Reference Feinberg and Shapiro1980; Grinspoon Reference Grinspoon2003).

This is an important section since students need to be able to imagine different possibilities; they need to use their imagination, and understand that science can be inspirational and exciting (Oliveira Reference Oliveira2008). It is an opportunity to inspire informed citizens (Des Marais et al. Reference Des Marais2003).

We start by trying to solve the Fermi Paradox (Webb Reference Webb2002; Michaud Reference Michaud2007). Although 150 possible solutions are considered, only 30 are analysed in detail. Students are encouraged to think about more solutions that are not included in the 150 list and are guided into discussing several of the solutions in their own groups and come up with the explanations for those solutions. Despite some very imaginative solutions, the fact is that it is always our solutions, our reasoning about what intelligent aliens may think and do, our way of thinking projected into extraterrestrial efforts, our interpretation of nature and our science. It is always about us.

The next chapter is about our Solar System. The planets and moons in the Solar System are toured. Their physical characteristics, the photos taken by the probes, the experiments performed on their soil, how well suited they are for ‘life as we know it’ and the probabilities of water and life on them as well as which type of life might be probable are examined. We look for what we already know, and in doing so we restrict our efforts to ‘looking for us’.

Subsequently the SETI program (Tarter Reference Tarter2001; SETI Institute 2008) is discussed. Its history, its projects, its results so far and the reasons for its results (Clark & Clark Reference Clark and Clark1999) are studied. The science behind it, and how it contributed to some of our current technology, is examined. Different strategies for listening and communicating with advanced extraterrestrial civilizations are considered. We observe, experiment and have fun with several signals sent by humans to outer space; including class activities that deal with them. Students also analyse a few mysterious signals received by SETI. The limitations in receiving and deciphering an extraterrestrial signal (Michaud Reference Michaud2007) are investigated, along with a few limitations in the SETI reasoning and in its current technology. The electromagnetic spectrum and the properties of the wave are studied. Studies on human communication with other species on Earth are reviewed, including communication within those species. Finally, the reasoning behind the idea of SETI, its premises, its assumptions, its problems and the similarities/differences between this reasoning and the arguments used throughout human history, which we studied in the first section of the course, are critically analysed. We debate how, for SETI to be successful, aliens need to be ‘humans’: they need to have the same kind of intelligence, similar reasoning, same curiosity and desires (wanting to communicate), similar level of development (in the end of the 19th century, Flammarion thought that Martians had a similar level of development as humans, using telegraphs), same frequency, comparable radio technologies, equivalent understanding of mathematics, analogous comprehension of messages, etc. Humans are still the measure for all things. An alien civilization needs to be very similar to a human civilization (Grinspoon Reference Grinspoon2003; Basalla Reference Basalla2006). Extraterrestrials need to be like us.

The following chapter is devoted to Interstellar Travel. Different ideas for exploration probes (Sentinels, Bracewells, Berserkers, etc.), and several current spacecraft projects, such as Orion, Ramjet and Solar Sailing, are analysed. A few possible future projects are considered, such as Generation Starships and Sleeper Ships. After examining the Theory of Relativity, with concepts such as Time Dilation and its Twin Paradox, the realm of science fiction with some speculative ways of travelling through the stars (e.g. warp drive, hyperdrive, wormholes, teleportation, etc.) is approached. Finally, all of these methods are discussed, and a critical analysis of what we can rationally expect in the future is performed. This chapter is totally dedicated to human technology, to humans spreading in outer space, to humans travelling to other planets, to the human colonization of space; this chapter is about us.

The last chapter is devoted to the UFO phenomenon, which is popularly thought as having an extraterrestrial origin (Sagan & Page Reference Sagan and Page1972). This chapter is not just about speculation, but about pseudoscience and the myths in astronomy (Grinspoon Reference Grinspoon2003), which are also useful in science education (Negrete Reference Negrete2002; Lanza & Negrete Reference Lanza and Negrete2007). UFOs are defined and their potential Earthly explanations are discussed. The history of the UFO phenomenon from antiquity until now is analysed, with an emphasis on the modern age of UFO sightings (Jackson Reference Jackson1992). The most important UFO cases worldwide are critically analysed. A few modern cases are scrutinized, focusing on several recent videos, examining them from a scientific point of view. This is done along with individual and group activities to help students question these supposed ‘evidence’ of UFO sightings. The lack of imagination shown by the ‘extraterrestrial UFO hypothesis’ supporters, who think that alien civilizations probably thousands or millions of years more advanced than us yet have spaceships similar to our current ones, is debated. The psychology behind UFOs, misinterpretations and myth-making throughout history is studied. The most important scientific research studies done on this subject and the most important researchers on this field (Koerner & LeVay Reference Koerner and LeVay2000) are considered. By the end of this chapter, the most famous alien abduction cases are dissected, and the lives of the self-identified contactees and abductees are inspected. Overall, the belief that UFOs are extraterrestrials is just that: a belief (Grinspoon Reference Grinspoon2003); it is a religious belief, where God and angels, who are in the sky looking at us, are substituted by aliens (von Däniken Reference von Däniken1968; Sitchin Reference Sitchin1976; Temple Reference Temple1976; Davies Reference de Bergerac1995; Shermer Reference Shermer2000; Grinspoon Reference Grinspoon2003). It is interesting that, like the gods, the aliens look the same as the people that invented them: white western civilization. It is an argument based on faith; people need to believe (Shermer Reference Shermer1997). This is an argument embedded in our own psychology: we want to believe because aliens make us feel special; just like the religious arguments in the History section, we want somebody up there that puts us in the central place of attention. Although there are many reasons for the UFO phenomenon, all Earth and human based, people prefer to believe in an extraterrestrial reason, against all evidence, because it is psychologically appealing (Grinspoon Reference Grinspoon2003; Michaud Reference Michaud2007). We live with an ET meme (Brake & Griffiths Reference Brake and Griffiths2002). Thus, the UFO phenomenon is all about humans. UFOs are us.

Science fiction

Although throughout the entire course science fiction works were often mentioned and discussed (Fraknoi Reference Fraknoi2003), the last section of the course is devoted solely to this subject. Some of the most important science fiction novels and movies (Rabkin Reference Rabkin1983; Pringle Reference Pringle1996; Mann Reference Mann2001) are critically analysed in detail.

Science fiction exploits scientific and social issues, while applying a lot of imagination. Albert Einstein used to say that imagination is more important than knowledge (Taylor Reference Taylor2002), since it stimulates creativity (TED 2007), which is important to solve problems, to inventing new technologies, to promote discoveries, to promote arts in society, to think about new scientific theories, etc. Thus, this section allows students to go further than just knowledge can take them (Machado Reference Machado2005).

After defining science fiction, the relationship between science fiction and human society is discussed. The relationship between science fiction and science (Krauss Reference Krauss1995, Reference Krauss1997), and how much they influence each other (Sagan Reference Sagan1979), is examined, with several examples provided. How science fiction inspires people (Brake & Hook Reference Brake and Hook2008) is discussed. Science fiction is interpreted as being a literature of probabilities instead of literature of prophecies (Brake & Griffiths Reference Brake, Griffiths, Norris and Stootman2004b). How much of science fiction is based on social (and technological) issues is analysed. What aliens in science fiction represent is studied.

The history of science fiction is examined, beginning with the person who is considered the father of science fiction, Lucian of Samosata, and his two fictional voyages to the Moon, written as satires of his own society. Next, Kepler's Somnium (1634), where he used analogy, anthropocentric ideas and believed Man was the best creature, is studied (Kepler Reference Kepler2003). Cyrano de Bergerac's Other Worlds (1657), two science fiction stories (travelling to the Moon and travelling to the Sun) which were satires of human society and parodies of Christianity, are examined (de Bergerac Reference de Bergerac1976); in contrast to all other authors, de Bergerac really criticized our anthropocentric view of creation, as well as the social injustices of the 17th century. Voltaire's Micromegas (1752), which is a satire of human ego, pride and vanity, is studied (Voltaire Reference Voltaire1989); we are so small, and nevertheless we think we own the universe. H. G. Wells' War of the Worlds (1898) is examined (Wells Reference Wells2005); a fictional invasion of the Earth by an advanced Martian civilization at a time when even astronomers thought they existed on Mars (Brake & Hook Reference Brake and Hook2006). It was a metaphor of Great Britain, a social and political criticism of the British Empire, which relied on technology to kill people with no regrets, like machines. It was a satire about imperialism and the vanity of Man. Subsequently, the class listens to the original radio dramatization of this piece, performed by Orson Welles, which led many people to panic.

Arthur C. Clarke's Childhood's End (1953) (Clarke Reference Clarke1980), Fred Hoyle's The Black Cloud (1957) and James Gunn's The Listeners (1972) (Gunn Reference Gunn1972), are all critically analysed.

A very detailed analysis of two novels follows: Carl Sagan's Contact (Sagan Reference Sagan1985), and Douglas Adams' The Hitchhiker's Guide to the Galaxy (the compilation of five volumes) (Adams Reference Adams2002). These two novels are in the mandatory reading list of this course.

Several important science fiction movies related with extraterrestrial life are examined. Students have the opportunity to watch, analyse and debate the movies Contact (1997) and K-PAX (2001). In addition, students may watch some episodes and documentaries about Star Trek and Star Wars: the documentaries analyse the science and the social messages underlying the episodes/films. Other movies discussing social and scientific issues are available for analysis: The Day the Earth Stood Still (1951), 2001 – A Space Odyssey (1968), Close Encounters of the Third Kind (1977), Superman (1978), Invasion of the Body Snatchers (1978), Alien (1979), ET – The Extraterrestrial (1982), The Abyss (1989), Stargate (1994), Species (1995), Independence Day (1996), Starship Troopers (1997), Men In Black (1997), Signs (2002), etc.; and the series: X-Files (1993), Third Rock from the Sun (1996) and Battlestar Galactica (2004).

The episodes and movies are reviewed, critically analysed from a social point of view, and the messages they meant to convey are scrutinized. The most common messages within science fiction movies are: the Universe is teeming with intelligence life; aliens are very advanced; aliens are very interested in us; aliens have different human characteristics, but humans seem to have them all; humans are constantly praised, and thus aliens would like to be humans, as it is mostly seen in Star Trek; what does it mean to be human, by comparing ourselves to non-humans (Rose Reference Rose1982); aliens are our past gods; science and religion are compatible; we can have a perfect integration of different areas of society; a person's life should be balanced; we should have an harmony between different parts of life, of a person's world; people should follow their dreams; our life and our world is what we make of it; humans should be constantly improving themselves; people should be happy, optimistic and tolerant; knowledge and critical thinking are crucial for a rational mind; the most important aspects in a person's life are family and the significant other; and the most profound discoveries are not in space, but within us.

It is seen that science fiction is not really about extraterrestrial life, but about human society, the culture of the time (Cohen & Stewart Reference Crowe2002); science fiction is a vehicle to make social criticisms and satires about the author's society. Annette Kuhn said:

Essentially, science fiction is a significant instrument of social criticism and comment on human life.

In the Science Fiction section, as in the History section, humans are the pinnacle of Creation; Man is the measure of all beings in the Universe; it's a glorification of human beings; it is all about humans, humans consider themselves the most important species in the Universe.

We define ourselves, by comparing ourselves with others (Sardar and Cubitt Reference Sardar and Cubitt2002); this is seen in all science fiction works that deal with aliens.

Science fiction adds nothing to our knowledge of aliens. It is all about us. Aliens are us.

Student feedback

The feedback so far about the course is anecdotal. Although all students fill anonymous feedback forms, the most comprehensive feedback comes from informal talks with students. As in other similar courses (Brake et al. Reference Brake and Hook2006), students seem to better understand the nature of science after the course, and they seem to have a wider scientific content knowledge.

Student evaluations of the astrobiology course, including comments of the students on the student feedback forms, indicate that students perceive classes as ‘motivating’, ‘engaging’, ‘extremely informative’, ‘fun’, ‘very interesting’ and ‘exciting’. Students believe that ‘the course is very well organized’, ‘taught in a very enthusiastic and passionate way’, with ‘insightful and useful knowledge’, where the ‘debate and opposite opinions are appreciated’. The students also ‘love the teaching style’ used by the instructor of the course. Students report that they complete the course with a feeling that they ‘evolved in the knowledge about science’, ‘understood how incredible science is’, ‘see science as a never-ending process’, ‘developed tools to critically approach’ different scientific subjects, were able to develop their own opinions about science in general and astrobiology in particular in a more ‘robust, comprehensive, and scientific’ sense. In addition, they state that the course helps them to ‘think outside the norm’. In the words of one of the students, ‘I think the class serves as an eye opener, providing a platform for critical analysis of alien life and the possibilities there in’.

The main complaint reported by these students focuses on the amount of content included in the course. They struggle in the beginning, due to being overwhelmed with information. Their perception is that they ‘have to work hard’ for this course, that the ‘course covers too much information’ and that they ‘expected less scientific content than what is in reality part of the extraterrestrial life subject’. Despite these complaints, in the end, most of them persist, are successful and obtain excellent grades.

Research and formal evaluations are currently being conducted to objectively determine whether the course is fulfilling the objectives, and if students attain gains in critical thinking skills and demonstrate a more sophisticated understanding of the scientific enterprise and the nature of science. Preliminary results are very promising.