How did our fantasy version of aliens come about and what do we know about the scientific plausibility of these creatures? We talked to comparative religion scholar Arjan Sterken and astronomer Rens Waters in order to find the answers to these questions. “I believe that aliens are a modern form of supernatural beings or monsters,” begins PhD candidate in Comparative Religious Studies Arjan Sterken when we ask him why we now associate supernatural beings with aliens and space. “Monsters usually live in unknown, unexplored areas. But we’re learning more and more about the Earth, and we’ve discovered almost every place on it, which means that other kinds of life must have gone to live in space.” Could this really be a possibility? When asked if extraterrestrial life could potentially exist in space, astronomer Rens Waters claims that this is a possibility that he has definitely not ruled out. “There is nothing supernatural about extraterrestrial life. If it does exist, it must obey the same natural laws as life on Earth. There are several things that are required for creating the conditions for the origin of life that is somewhat similar to life on Earth as we know it. For example, a central star (like the Sun) needs to exist. And there are billions of these, which means that there are plenty of possibilities. In addition to this, there need to be planets around the star. We’ve found that the majority of stars have planets (exoplanets) around them, which means that this condition also exists. We then need to look at which planets are suitable for life as we understand it. These are planets that contain a rocky substance, and where liquid water and an atmosphere exist. This type of atmosphere actually determines the conditions on the surface of the planet and, by extension, determines the possibility of the emergence of life on this planet.” Then there are a number of chemical elements that are essential to all life on Earth. These elements must also exist on a planet before any form of life can emerge. Rens: “These elements are: carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorus. In our solar system we have four terrestrial planets: Mercury, Venus, Earth and Mars. Mercury has an extremely thin atmosphere, but it’s also so close to the Sun that it’s unlikely that life could have developed there. When it comes to Venus and Mars, the latter seems to have the best prospects. In the past, the conditions that existed there closely resembled the conditions on early Earth: moderate temperatures, an atmosphere and liquid water. In an effort to further investigate these conditions, NASA is drilling holes in the surface of Mars. Samples of these will be taken and these will be analysed here on Earth.” Rens maintains that this research study should be completed in the next ten years. “We’ll then carry out an analysis in order to determine whether fossils or perhaps even microbes can be found in these samples. And this will allow us to determine whether life is present on Mars - or has ever been present - regardless of how primitive it is. This means that there are exciting times ahead of us.” Venus - where it is currently too hot to live due to the dense atmosphere and the substantial greenhouse effect - is also being examined more closely. Both NASA and ESA are planning several missions to the Earth’s twin in an effort to better understand this planet’s history. In addition, the moons of the outer planets in our solar system also offer possibilities for life. “Io, which is one of Jupiter’s moons, is extremely water rich. The outside of this moon is very cold and frozen, but the inside is warm. And it’s here that a very salty, liquid ocean can be found. NASA and ESA both plan to use probes to investigate the composition of Io. It’s exciting to think that it’s possible that under the frozen surface, the same chemical reactions are occurring that may have taken place in our oceans when the Earth was first formed. This could enable the creation of some form of life.” Changing vision Arjan has seen that there has been a clear shift in the representation of extraterrestrial life over time. “Supernatural beings are ambiguous creatures. They are neither good nor evil by nature - they’re predominantly strong, and have all kinds of powers that humans do not possess. You never know in advance whether they’re on your side or not, which means that you always need to be wary of them. For example, think of Zeus, who was primarily known for his impish behaviour, even though he was a Greek god. While these creatures were primarily placed within an explicitly religious framework before the Romantic era (they were either angels or demons), these days they tend to be interpreted in other ways. Thanks to the modernisation and technologisation of our lives, supernatural beings are now being interpreted in such a technological way: flying around in aircraft that are technologically far superior to our aeroplanes.” Yet supernatural beings, including aliens, are not merely scary. “When we analyse these stories, we always see that they centre on advanced beings who are technically and spiritually way ahead of us humans,” says Arjan. “What we can also see is that supernatural beings and aliens have been somewhat romanticised and these extraterrestrials are being perceived as being less and less ‘scary’; think of Netflix series like Lucifer where even Satan is portrayed as a charmer who shows his human side or films like Beauty and the Beast and The Shape of Water, in which the so-called monster develops a relationship with a human being.” But is this something that we are actually ready for? “At present, there are places in our galaxy where planets and stars are being formed. The James Webb Space Telescope was launched into space last December. The first readings will be available in July and these can be used to determine the composition of the essential elements of those planets like Earth. The Webb telescope will also be able to determine what kind of gases and clouds exist in the atmospheres of exoplanets. These results could provide new information about the composition of planets outside our solar system and consequently verify whether water and other molecules that are vital to life are available,” says Rens. Even so, he does wonder what implications this may have. “I find it interesting to see that mankind’s world view has changed. We’ve shifted from a view in which the Earth was at the centre of the universe to a view in which there are billions of stars and planets, and our Sun is an ordinary star among many others. The last unique peculiarity that we possess as planet Earth is that intelligent life developed here. I do wonder how it will affect us humans if extraterrestrial life really is discovered. From a philosophical perspective, I find it quite interesting to think about how this will affect our world view. It seems that nature has already created the conditions for the emergence of life in the universe billions of times, so you’d almost have to expect that the beginnings of evolution and life have occurred more often than just on Earth.” Arjan has a different perspective on this. “We’ve never felt alone on this Earth, nor have we felt alone in the wider universe. Our world has always been populated by all kinds of beings to whom we’ve ascribed intelligence and powers, even if they were supernatural. Because we think we understand our planet so well, we’ve now moved the supernatural world further up into the Universe. Whether or not we’ve actually made contact in the many UFO and abduction stories that have circulated, we’ve been preparing for extraterrestrial contact in our fantasy and imagination since at least the Second World War.” Photo: Florentine Pautet via Unsplash