Aliens or extraterrestrials is perhaps the number one topic in science fiction movies. People love to fantasise about bizarre species visiting Earth or us visiting them. Of course, intelligent lifeforms are preferred for first contact, although it is not guaranteed they will come in peace.
However, if another beings exist out there at all, we are more likely to encounter unintelligent ones first. Why is that? Because of communications. It is not necessary and it is not likely that all of the lifeforms around us would have evolved enough to be intelligent.
So far, we haven’t picked up a signal from another civilization yet and it will take some time before we will be capable of doing so at longer distances. But still aliens are likely to be found in our own neighbourhood of star systems.
It will be pretty exciting to discover life on another planet no matter if intelligent or not. In this article we will speculate on a mix of theories from movies, supported by scientific facts. By doing that we might know what to expect on planets with different conditions.
Different conditions, climate, orbits and stars can define absolutely different evolution, compared to the one on our world. That’s why there are endless possibilities of how life on other planets might look like.
Theories for alien life
Biochemistry. CHNOPS stands for carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. Those are the six main elements that are the building blocks of 95% of Earth’s species. Life on Earth is based on carbon and needs water to thrive (with some exceptions).
Some biochemical hypothesises suggest, that non-carbon based life might exist somewhere out there. Not only in science fiction, but also in theoretical science. Such beings, if existent, might be radically different from us.
Various theories propose that silicon-based biochemistry might be possible under certain conditions. Anaerobic life-forms are another alternative hypothesis, which replaces the oxygen with chlorine and still remains carbon-based.
This, of course looks poisonous to us, but aliens from another world might be “built” by such elements. Biochemists were pretty excited by the “finding”, that arsenic-feeding bacteria were discovered in Mono Lake. unfortunately, those bacteria turned out to be using phosphorus after all.
Arsenic isn’t part of those bacteria DNA, but still they manage to survive in this environment, thought to be poisonous for all species on Earth. Such discoveries hit that there is still hope in finding other species with different biochemistry from ours.
There are numerous alternatives to the carbon structure of alien life like: selenium, tellurium, sulfur, some metals, non-water solvents such as ammonia, methane and many more. Time and science will show, if they are possible.
Multicellular organisms that do not need oxygen were found in 2010. So far only bacteria were reckoned to do that. This opens up a tons of new questions and speculations for the scientific world.
Anatomy. Most scientists agree that our species have overgone a long period of evolution. An ancient worm went through a complex evolutionary process to result in larger worms, that over time developed legs, arms and intelligence.
What I dislike about Star Trek is that more than 90% of the aliens there are humanoids. The females usually have have human-like breasts (preferably big ones). This was once explained as a grand design of an ancient race that “seeded” life on life-supporting planets. They “engineered” it so that evolution processes “produce” humanoids in most of the cases.
And this trend is not only in Star Trek. We are so used to our worm-ish body shape, that most of us can’t imagine other species, that will probably have far more odd anatomy. But there are movies that are crammed with hundreds of ideas of how would creatures from another world look like and they are very different in shape and looks.
We could encounter unipedal (with many legs) extraterrestrials that might have wider and lower bodies, compared to ours. They could be insects, like many like these here on Earth. Nobody has proven that under the right circumstances, insects can’t evolve to more intelligent and complex species.
Other movies and books depict amorphous, plant-like, mechanical or energetic (consisting of pure energy and particles) aliens. Extraterrestrials in sci-fi could be also categorized, if they are mammals, marine, reptilians and other types. The overall astrobiological options are endless and so is our Universe.
Environmental characteristics. Species on another planet will surely be influenced by their planet’s climate and environment. The star that a planet orbits around can very well influence the alien inhabitants.
First thing to take into notice is the star’s color. Our sun looks yellow on Earth’s surface (in fact, it is white without looking through the atmosphere). Because of the yellow light photosynthesis results in green as plants’ dominant color here.
Imagine other planets, that orbit a red, or blue star. Plants and animals would look entirely different. Their colors and sensor organs would be adapted to the color of their sun. Planets with red or blue plant life could be very real, if life is found in such star systems.
The sun’s brightness and luminance could determine how many eyes would a life form have or what kind of light will they detect. A dim star suggests that species need organs more sensitive to weak light or on the contrary – filtering intense light.
Gravity (compared to Earth’s) is another thing writers and scientists take into notice, when speculating on alien life. For instance, high gravity worlds might support life forms with strong legs and short stout body structure, to sustain the strong pull.
On the other hand, if you visit a low gravity world, you would find beings that evolved so that they can hover flawlessly in the atmosphere. They wouldn’t need strong bodies, because they wouldn’t have strong gravity to struggle with.
Communication. Nobody said that talking the way we do it, is the only way. Science fiction suggest numerous ways how could other species do it. They can use electric or any kind of electromagnetic waves to “talk”.
Our speech is nothing other than waves in the air. Talking to aliens will sure be a challenge during the first contact. They could be telepaths, communicating with gestures or speaking undecipherable language.
In search of aliens
For now, our capabilities for discovering life on other planets is very limited. We have began to spot another Earth-like planets only recently and pin pointing life forms on their surfaces or their atmospheres is something far more challenging.
The first thing to do will probably be detecting their communication signals, if intelligent aliens exist and use similar to our radio emitting technology. The other option is developing interstellar travel technology, that will leave no room for assumption and make this exploration happen faster.