The question of the existence of intelligent life outside of Earth has been a major scientific inquiry for many decades. With the recent rise in UAP (unidentified aerial phenomena) sightings around the world, this question has bled into mainstream media. So, it begs the question: is there more life out there? I, along with many others, would argue so.

Astrobiologists are viewing it as an ever-increasing possibility or even a plausibility.

The current base requirements for life as we know it are as follows: a source of energy, liquid water, carbon and various other elements. According to a 2018 article by Forbes, an estimated 100 billion planets just in the Milky Way galaxy could meet this basis for supporting life. Based on numbers alone, it seems almost inconceivable that only one planet has succeeded in sustaining advanced life when so many others have the environment to do the same. Because of the overwhelming mound of evidence supporting the theory of life on other planets, and because of my innate human optimism to believe, I stand firmly on the side of extraterrestrial life existing outside of our world.

The most compelling case brought forth in this discussion is, as mentioned prior, the myriad of planets in the universe. Of the 100 billion planets in our solar system, a number that is only expanding, it feels statistically unreasonable that we are alone. Though many of these planets can be disregarded as impossible to accommodate life, if even one in the 100 billion planets of the Milky Way has evolved technologically advanced life, combined with the two trillion separate galaxies in the universe, the possibility of life escalates to heights beyond comprehension. A 2021 Washington Post article states that astrophysicists agree on the existence of at least one or two planets per galaxy that can support intelligent life. Based on the sheer quantity of potentially hospitable planets, the argument that we are alone in the universe sounds especially doubtful.

One of the first rebukes against the claim of alien existence is simply that no contact has yet been made. Despite all our efforts: the launching of telescopes, sending of radio signals and landing of interplanetary rovers, there has been a continuous silence in response to our attempts at communication. Surely this proves that we’re alone, that because no signs of life have been picked up, none exists. But there are a multitude of reasons why there have been no replies to our contact. People have been so eager to transmit a radio message for all the universe to hear that we have forgotten that these take time to relay. A lot of time, in fact. Radio signals are able to travel at near the speed of light, but to reach the closest neighboring galaxy to ours, the Canis Major Dwarf, it would take over 25,000 years just for the signal to get there, let alone the time it would take if we received one back. Put into perspective that we have only been doing this since 1961 — an insignificant 62 years — with the launching of the search for extraterrestrial intelligence (SETI), it’s no wonder why we haven’t yet heard anything back.

Okay, so let’s rule out communication via radio signals. What about telescopes and rovers? If other forms of life are out there, how come we haven’t discovered any through our cosmic eyes? The simplest answer to this is that we are still in our infancy of exploring space. Since the mid-1990s, we have officially labeled over 5,000 exoplanets — planets that orbit stars out of our solar system. This is less than a drop in the bucket when compared to the quadrillions of unidentified planets waiting to be discovered. Technology for intergalactic exploration is still young, but the deployment of telescopes and rovers has only helped us grasp a greater understanding of space and, as science improves, the probability of finding intelligent life will surge. As stated by NASA’s Astrobiology Division, the official identification of exoplanets has been primarily due to telescopes, including the Kepler Space Telescope, the Transiting Exoplanet Space Telescope (TESS), the Hubble Space Telescope, and the recently launched James Webb Space Telescope (JWST).

To further lock in this point, consider two of NASA’s rover missions: Curiosity and Perseverance. These missions were set in place to gather samples and discover the history and possibility of life on Mars. During Curiosity’s two years on Mars, it determined that the support of life was completely possible four billion years ago. As Perseverance continues through its mission, it will attempt to find any signs of previous life on Mars and will collect samples of rock and soil to be examined on its return to Earth. This is a massive leap since our last attempted search for life on Mars in 1976, with the dual Viking landers resulting in failure. Now, because of the help of rovers, we know that Mars used to be sustainable for possibly intelligent life, and with the continuation of scientific development and rover missions, the conclusion of if life existed on Mars is nearly within reach.

Another reason why extraterrestrial life is probable is the perseverance and resilience that life on Earth has shown. The habitability of planets is determined by the aforementioned conditions for life’s survival. Water, carbon, energy and other elements all are needed to cultivate and grow life on a planet, and a near-perfect circumstance needs to be in place for this to work. Temperature is a vital factor in the viability of life on a planet due to its effect on water and the atmosphere surrounding a planet. Life is able to survive in temperatures ranging from 5 °F (-15 °C) to 252 °F (122 °C), granting a generous scale on the possible habitability of a planet, and in turn an increase in the potentiality of life. Studying life in Earth’s intense desert environments has shown that microbial life can sustain itself in areas with only a small amount of rain, fog, snow or humidity. Between the extremes in which organisms are able to endure and the estimated 40 billion planets in our solar system that can conceivably promote the growth of life, the likelihood of at least one other planet housing life as we know it ㅡ or life as we don’t know it, something harder to understand and estimate ㅡ becomes astronomically high.

The discovery of intelligent life off of Earth’s surface is one that will be cemented in history forever, and one that I believe to be unavoidable and undeniable. Based on the volume of evidence gathered even in the past 30 years that supports life on other planets, it grows ever harder to argue the opposing side of the subject. Regardless of if we ever make contact with aliens, the discovery of life is one that will be left to our descendants and is dependent on those intrigued and eager enough to step into the field and advance science enough to make history possible.