Welcome. Come in, please. May I take your coat? If you don’t mind removing your shoes you can place them there. Would you like something to drink? Have a seat anywhere you find most comfortable. Are you hungry?
What does it mean to be a host, to welcome a guest? Traditions vary with regions, families, cultures, trades, and religions. Do you offer your guests wine? Or tea? A plate of areca nut and betel leaf? Do you offer them tobacco, or cannabis? A meal, a bed, or nothing? One way to approach such questions is to imagine what your guests need or want, recognizing how it feels to be away from home. A host grants special rights to guests, saying things such as “Take what you’d like” or “Make yourself at home.” But where are the limits? These issues are challenging enough when hosting humans on Earth. What would it mean to host extraterrestrial guests? How do we imagine hosting the truly alien? Is there a frame of reference for thinking about a guest’s needs outside the obvious physical ones?
Imagine if, as a human visiting another world, you were given only what your body requires to survive. You might be placed in a space no larger than a coffin, with breathable air pumped directly into your lungs and nutrients and liquid into your blood. An extreme example, but what reason do we have to believe we could communicate our preference for more space, or for light and windows to use our eyes? How about our desire to step outside for a breath of fresh air or to consume a variety of foods? None of these would be obvious if our alien hosts—who might have as little understanding of our minds as we would have of theirs—assessed only our basic biological needs.
When anthropologists compare groups of humans across space and time, our commonsense ideas about what’s normal turn out to be specific to places, times, and experiences. Sometimes these differences can be translated adequately enough between human cultures, but extraterrestrial life will present vast and possibly unimaginable biological and cultural differences. Given broadly similar environmental conditions, even nonhuman life on Earth has evolved great diversity of form, behavior, culture, and appearance.
Aliens we meet will be shaped not only by their home world’s evolutionary pressures but also by intercultural encounters with other species over thousands or millions of years. Imagining the differences produced by variations in atmosphere, gravity, and light, along with planetary histories, cultures, and events requires both astrobiological and anthropological imagination. Speculation about extraterrestrial life sometimes describes aliens in terms of what seems rational, common sense, natural, or familiar here on Earth. One of the lessons of anthropology, however, is that what we perceive as normal isn’t universal, even on our own planet.
Perhaps our extraterrestrial guests’ mental, social, cultural, or physiological needs would be incomprehensible to us, or if we did understand them, even horrific or taboo. Can our earthly expectations and imaginations account for extraterrestrial possibilities? Imagine hosting visitors for whom the consumption of food is always a private affair, an act reserved for solitude—much as we set aside toilets in private rooms. Perhaps our visitors are used to being the only individuals within 100 square kilometers or instead prefer what we might consider very crowded conditions. Maybe they only feel comfortable when accompanied by a companion of another species, but instead of a dog or cat it’s something vastly different, like a mollusk that emits clouds of fragrant, multicolored gas on specific cycles. Our guests may even have symbiotic relationships with these creatures and always expect to meet them wherever they go. The presence of such companions could be the minimum they expect, a chance to experience the unique gasses from their host’s companion mollusk. What if speaking out loud is only acceptable between family members, and all other communication requires writing, dancing, remote signal transmission, or something else? How would we know? Perhaps when we host extraterrestrial life the only way to learn will be to make mistakes, note the consequences, and then try again.
We might think we could adopt a neutral, peaceful position from which to approach extraterrestrial guests, a beginning posture that communicates only our willingness to listen. But even when we are sitting still, just breathing, without deliberate expression—in our most supposedly inoffensive states—we are communicating our mammalian sensibilities. We can’t help shining our glossy, wet eyes at our visitors and exhaling gasses in their direction. Our skin changes color, we sweat and emit chemicals, our digestive system grumbles. We point our faces toward our guests as we stare, with our orifices and moist, blinky movements, like an arsenal of biological weapons. Teeth, eyelashes, breath, nostrils, tears, sniffles, earholes—these features could be beautiful, hilarious, offensive, or threatening to our extraterrestrial visitors.
Without thinking much about it, we nod, gesture, emote, and express. Even the machines we build perform equivalent expressions so that we can interact with them: Small lights illuminate to tell us the apparatus is running, it makes a startup sound, the lock clicks into place, the switches flicker and glow. If we sent a robot to meet our guests, in the hope of escaping unintentional communication, we might inadvertently overwhelm them with a cacophony of electromagnetic radiation, flashing lights, hydraulic hisses, or other sensory input.
Perhaps, instead, we would be too quiet, or too slow, moving like trees from their perspective. Or maybe we’d be too fast, like gnats, and so short-lived that our entire lives are but an instant for our extraterrestrial visitors. Would we be able to cross not only the cultural, biological, and sensory divides between our guests and ourselves, but also the temporal barriers?
If we host extraterrestrial life one day, we might not be able to communicate a simple idea such as: “We enjoy talking to you. Meet us here again tomorrow.” Understanding requires explanations built on other explanations, and context built on context. The gulf of differences between us and the extraterrestrial other may mean that a simple sentence takes a human lifetime to communicate. Hosting extraterrestrial beings will require linguistics, biology, art, physics, engineering, and other tools. It will also demand anthropological insights about intercultural contact and our human tendency to naturalize and then universalize culturally specific behavior and beliefs. Most of all, though, it will demand generosity, imagination, and a great deal of patience.