The Possibility of Life on Another Planet

Earth is the planet that many different organisms call home. Humans, plants, animals, and even microorganisms live on Earth. Though these organisms live there, could there be a possibility that similar organisms exist outside of Earth? Astrobiology's main goal is to answer this question. What planets are there that could potentially hold life? Life can come in many forms, so while there may not be intelligent life in the universe, there could be life nonetheless. There are special places called habitable zones which is the distance from a star where a planet could hold liquid water, something that is crucial to make a planet habitable. Examples of these planets are the exoplanets that fall into the TRAPPIST-1 system. TOI 700 d was one of the first planets discovered in this star's habitable zone. Though Earth is the planet that everyone lives on, it is safe to say that there is a possibility for life to be found outside of Earth, if just a small one.

Keywords: Space, Possibility, Astrobiology

Earth is the planet that millions of animals and billions of people call home. 4.6 billion years ago, the earth was nothing more than dust particles and gas floating around in space, until finally, those dust particles collided with asteroids and other smaller planets to form the Earth that plants, animals, and people live on today. But before that there was the Big Bang; the creation of the universe. It exploded in on itself, expanding space, forming simple elements, and creating the first stars and galaxies. When thinking about things such as the formation of the universe and the formation of the earth itself and many of the other planets, everyone has their own beliefs as to the how and the why. How is it possible for people to live on a seemingly floating rock in space? Why is it that Earth has the ability to sustain life and why can’t other planets hold life? Are there other planets that are able to support life? The possibility of life on another planet, the determination of hospitable planets, and the planets that have the potential of being the next Earth are the questions that astrobiologists are on a mission to answer. What is out there and what planets hold that mystery if any hold it at all?

As mentioned before, astrobiologists are on a mission to answer whether the possibility of there being life on another planet is an actual possibility. It is one of the fundamental goals that astrobiologists seek to meet. Astrobiology is a branch of science that combines biology, the scientific study of life, and astronomy, the scientific study of celestial bodies and celestial occurrences. Astronomy is used to explain the evolution and origin of space and its mysterious, unexplored, and unidentified articles. Biology is used to study life and explain the evolution of life and the ecosystem that humans, plants, and animals alike live in. So, when combining the nature of those 2 sciences, one can come to the conclusion that astrobiology is the study of life in the universe. The universe and space are very mysterious things. The ordinary person lives within it but knows essentially nothing except for basic objects and occurrences that take place within it or can be seen on Earth like meteor showers and the northern lights, also known as the aurora borealis. It’s alarming to think about living someplace you know nothing about. So, astronomers, astrobiologists, and other types of scientists work together to piece together theories and hypotheses to come to an understanding of where people stand in the world and the universe. They piece together what’s around them. Astrobiology in particular is very important in itself because it searches for and answers the questions that many people are afraid to ask themselves. That question is: Are humans the only ones here? In this context ‘here’ refers to the universe as a whole. Not just Earth or the Milky Way, but the universe and its many celestial bodies far out into it. Are humans the only intelligent life there is? That is the question astrobiologists sought out to find. If they come to find that humans aren’t the only life there is, intelligent or not, that will be a breakthrough in the world of science. “By studying life on Earth and in space, we can better understand the constraints for life and why Earth is the only known host of life” (De Mol, 2023, para 1). There is another branch of astrobiology that specifically deals with finding out the possibility of life on different planets as well as how those planets might be composed. Finding out what habitable planets are composed of can lead to discoveries about unknown habitable planets such as what makes a planet habitable. What is the most common factor between these planets? That’s what exobiologists strive to answer.

Because Earth is the only known habitable planet, it is used as the basis of research or as an outline for what a habitable planet is. According to SEEC (n.d), NASA has come to find that a habitable planet needs nutrients, energy, and of course, liquid water. Liquid water is very hard to come by in space as it is extremely cold or extremely hot depending on where the planet is in the solar system. The farther away from the sun a planet is, such as Jupiter or Saturn, the colder the water will become, and the more chilled and frosted the water that there is on a planet becomes until it finally freezes and becomes hard to get to. “An entire world covered with ice, but underneath that ice, an ocean.” (Discovery UK, 2018. para.). Being closer to the sun is not all that great either. The closer a planet is to the sun, like Mercury or Venus, the hotter any water there is gets, until finally, that water is boiling hot. Not many living things could survive in that, depending on how one would define the word living. According to H.P. Klein (1968), life cannot be defined in simple terms. Life has many different properties, life has to be defined as such. It has to be defined by its properties. Earth is the perfect planet for many, if not all, forms of life to live on as it falls in the sun's habitable zone. A habitable zone is defined as “the range of distances where conditions may be just right to allow the presence of liquid water on the surface” (Kazmierczak, 2020, para 1.).