Does Life Require a Star?

While it seems to suggest a lack of intelligent life in the rest of the universe, the Fermi paradox merely suggests that we do not know where to properly search for intelligent life. We assume that the methods we are using are efficient, even though we may be looking past planets that possess intelligent life.

A large assumption that leads to the proposed paradox is the assumption that intelligent life resides on “Earth-like” planets within a star’s “habitable zone”. When looking for life in the universe, we single out these types of planets before looking closer to see if they possess intelligent life. This seems to be our biggest flaw when it comes to direct planetary observation.

At this point you are probably wondering, “But why look at any other kinds of planets? Is it not a waste when the only life we know of is inside the habitable zone of our star?” While this may be true, we do know of life that can survive without receiving any light from a star. That life just so happens to be found at the bottom of our oceans.

Down at the greatest depths of our oceans, there is no sunlight to be found. Sunlight being the source of energy for just about every food chain, one would think there would be no life to be found. But, if one stumbles upon a crack in the seafloor known as a hydrothermal vent, one also stumbles upon a diverse, self-sufficient ecosystem.

How is this possible? At the base of the food chain surrounding a hydrothermal vent are a group of microbes that are chemosynthetic, or chemoautotrophic. This means that, unlike photosynthetic organisms, they convert chemicals instead of light into the organic molecules that are necessary for survival. These microbes can do this with sulfides and carbon dioxide, which are constantly shooting out of the sea floor through the vents.

Image: http://www.sci-news.com/biology/life-hydrothermal-vents-07772.html

With the microbes converting these chemicals into energy, other organisms can thrive around the vents. Organisms like tube worms and shrimp can eat the microbes and receive their energy. The food chain continues up, including fish, crabs, anemones, and even octopi.

This proves that it is possible for a complex ecosystem to evolve by “abnormal” means in an area that receives no sunlight. If we know that it is possible for these types of ecosystems to exist, then who knows what other kinds of ecosystems could arise.

As long as we continue to look past planets that are not a certain distance from a star, we will continue to look past possible ecosystems and intelligent life. We cannot assume that the life we are looking for is in an ecosystem like ours. This ecosystem may be closer to that of a hydrothermal vent, relying on chemical energy rather than that from a star’s radiation. Or it may be completely different. Until we change the way we approach the problem, we cannot know.

Source: https://en.wikipedia.org/wiki/Fermi_paradox