Does astroscience enable the identification of potentially habitable planets and extra-terrestrial life?

Our universe is an infinite, evolutionary expansion of time and space, where which humanity long questioned the existence of life beyond Earth. For millennia, such ideas were confined to philosophy and theology; only with the advent of telescopic observation in the Renaissance did empirical study begin to challenge purely speculative cosmology. Scientific claims including the Drake Equation, which estimates how many civilisations us humans can communicate with using several variables such as the number of habitable planets in other solar systems and how many contain intelligent life. But this hypothesis is challenged by the Fermi Paradox: if the universe is truly endless which raises the possibility that other habitable planets and alien life exist, why hasn't there been any sighted yet?¹ It also poses another question, what truly is the meaning of life? The only kind of intelligent life we currently know as of now is on Earth, which could limit our knowledge in recognising others.² For many years, scientists have managed to separate philosophical speculation and empirical studies. Exoplanets within the Milky Way Galaxy is a definite possibility, and a couple that may have contained life have already been discovered, such as k2-18b in our "Goldilocks zone", where liquid water may exist, about 120 light years away from Earth, found through the James Webb Space Telescope, having potential conditions that are habitable for us humans.³ Others may believe that due to the complex habitual structure of the Earth such as plate tectonics conducting carbon recycling, temperature regulation, a magnetic field and an ozone layer shielding against Sun radiation can never be replicated on other planets.⁴ The idea of truth is subjective, and this essay is going to examine, evaluate, measure and synthesise the scientific methods, discoveries, successes and limitations to determine the extent which astroscience potentially enables the identification of extraterrestrial life and other habitable planets, while also considering future technological advances and analytical developments which might further fuel our search.

Over the course of time, the topic regarding the search for extraterrestrial life has been a large debate for many years, yet continuous proof is discovered each day. For example, identified in 2017, Oumuamua is recognised as the first known interstellar object due to its unusual and alien qualities, such as being the approximate size of an American Football field, having a "pancake" like shape, a rate of tumbling every 8 hours as well as an unexplainable acceleration and no cometary tail.⁵ The oddity of this object could therefore imply that this object could possibly indicate artificial origin. But to claim that is true isn't correct as this controversial debate is still happening even to this day as well as there being a lack of empirical knowledge on the subject. Yet when it comes to identifying what truly makes a species extraterrestrial, astroscience is crucial in playing such a role. As humans, we are aware of the simplest aspects of our own biology: water, blood rich with oxygen, as well several other elements required for our survival. However, one thing we as a race are not that others are is that we are not extremophiles.⁶ Humans can't survive conditions involving critically low or high temperatures or anything too acidic or alkaline for our bodies to handle. However, if we couple with the Oxford definition of alien as an adjective, "strange" and "different from what you are used to", this creates the implication that aliens themselves out there are extremophiles given they could be more intelligent life forms that are clearly different from us. There has even been potential evidence that we have actually connected with these forms of life before, and the answer is closer to us than we think. Due to the Sun being the closet star to us, it has a massive source of radiation where the frequencies of such can reach several levels, including the radio spectrum. And when events such as solar flares or storms occur, massive bursts of radio waves are produced which can get picked up during geomagnetic events. Although the statement may seem hypothetical, it is possible that if there is potentially alien life, they could interpret these flares as messages, a form of communication.⁷ Yet such simply stretches the empirical values of astroscience so far so while it isn't impossible, it certainly seems too enthusiastic to be considered true. Human technology could be entirely different to alien technology is the main reason as to why we haven't discovered whether this is true, but that doesn't mean it isn't. Even if that hypothesis is disproved, there is nevertheless a continuous hum whirring across the Milky Way Galaxy, coming from sources like giant gas and dust clouds and the regions where stars are formed, where they are a source of continuous cosmic noise, meaning the use of mathematics and astroscience could allow us to decrypt potential messages that could be shown throughout our galaxy, if any. 5000 tonnes of space dust fall onto our planet annually meaning evidence arrives every second time passes on our planet.⁸ Asteroids that we have discovered and sampled such as Bennu and Ryugu contain the elements that are essentially for life to be formed.⁹ But proof of alien life is not as complex as searching for proof beyond our universal understanding to discover, it could be as simple as a certain element in our everyday life. Fluorine is incredibly scarce on Earth and it's discovered in less than 0.02% of known natural compounds.¹⁰ However, as the most electronegative compound discovered, it therefore makes the energetic demand for carbon-fluorine bonds demanding, and the strength to break said bond due to the electronegativity difference reflects how it's costly to incorporate fluorine into our biochemistry.¹¹ And it is these challenges that suggest life beyond Earth as such would also, like us, avoid using compounds that contain fluorine, allowing for biosignatures to be more easily detected beyond Earth that could be more indicative of biological activity.¹² Furthermore, the concept of the Kardashev Scale could help us grab further leads in regards to alien life as it categorises civilisations based on energy levels.¹³ We as humans are ranked as Type 0, which could imply that eventually we could find Type I or Type II civilisations, meaning there could be life that harnesses the same power as stars or galaxies. Furthermore, based on the findings of SETI, which is tasked with listening for possible radio and laser signals from intelligent life itself, suggests the hypothesis that there could be possible evolutionary similarities between our life and alien life, especially the photosynthetic aspects of plants and the biological features of marine life, particularly crustaceans and gills.¹⁴ But such may also raise the questions and speculations, how would alien life thrive? There is a possibility that, despite its similarities to creatures of our own world, they would have to live under different gravitational forces, chemistry or radiation environments compared to us.¹⁵ Such environments could create conditions that are very different to the ones we have on planet Earth. Furthermore, detections can also be prone to human errors¹⁶, such as how the possible theory of solar flares being accepted by alien life as messages could be completely false since they often happen naturally, not unexpectedly. On top of this, the claim that exoplanets could permit liquid water isn't a direct meaning alien life exists, scientists still have to be cautious that these are just hints rather than proof.¹⁷ Nevertheless, it's safe to say that astroscience played a substantial role in enabling the identification of extra-terrestrial life as it certainly provided us with not just further scientific evidence that backs popular theories of alien life such as the Drake Equation and the Fermi Paradox, it also provides us further questions about what we don't know yet about alien life and if the knowledge we currently have is legitimate, or if there is still much more to seek out, where current discoveries are limited by human speculation and technological limitations.

If the length of our universe is truly infinite, then that must also mean the number of atoms that make up our universe is infinite as well, a direct implication that there are also an infinite amount of other planets and galaxies¹⁸, which we are aware of since our current knowledge tells us that the Milky Way Galaxy isn't the only galaxy in the universe, let alone the only one with planets. The late twentieth-century development of the detection of exoplanets marked a decisive shift from speculative cosmology to measurable planetary identification. In fact, these "exoplanets", planets discovered at further edges than our observable universe, are consistently being detected through complex methods such as transit dips and microlensing.¹⁹ Prior to the 1990s, exoplanets were a largely theoretical concept but the first confirmed detections in 1995 of 51 Pegasi b marked a decisive historiographical shift in planetary science. In 2022, HARPS analytical data detected "super-Earth" HD 20794 d which is about 20 light years from the Earth and 6 times its mass, suggesting that there are answers already, even if journeying to them takes several years with today's technology.²⁰ On top of that, despite it being a small detail that the exoplanet is 6 times Earth's mass, it could suggest that the gravitational force on the planet is greater compared to us, possibly by 2G, showing that the atmosphere of the planet could be "thicker" compared to Earth, leading to further environmental factors like different coloured skies, higher pressures, stronger winds and even greater air resistance. Moreover, another concept which exoplanets tend to follow, similarly to Pluto and Charon, is the concept of tidally locking, where one side of the planet is facing the Sun, scorching hot, whilst the other faces away, freezing cold.²¹ With such conditions in mind, discovered exoplanets known for such layouts such as HD 64633 d, founded in 2024, it could be suggesting that astroscience convinces us that exoplanets have greater environmental instability compared to us, further branching into complex ecosystems and almost scientifically unexplainable biodiversity. Furthermore, when stars are formed from nebulae, nuclear fusion in them create heavy elements like carbon and oxygen and when stars explode, they spread these elements across the galaxy in supernovae, mandatory for the building blocks of rocky and gaseous planets.²² This could also suggest that exoplanets in terms of formation are not too different in comparisons to our planets, where the death of stars scattering elements across are responsible for layering their foundations. However, there are also certain elements that planets have that could be prevent them from becoming habitable. Even if life is complex on all types of exoplanets, it only occupied the tiniest slice of geological time, as catastrophic events such as supervolcanoes, impacts and climate shifts repeatedly wind back the evolutionary clock, with Earth being no exception.²³ Our Earth might not have faced the same occurrences that exoplanets could have faced, or as frequently, as such can define what conditions allow life to thrive. Furthermore, as mentioned earlier, conditions such as tidal locks and differing planet mass and gravitational forces can affect an exoplanet's habitability. In our Earth, we have a moon to stabilise our axical tilt and climate, plate tectonics to recycle carbon and temperature as was as a magnetic field and ozone layer to shield us against radiation.²⁴ The interdependent link between extraterrestrial life and habitable planets are clear since any life that may life on exoplanets have different levels of elements or radiation required for survival, which we might not know yet but given how they have been so far thanks to astroscience for differing to humanity, seems highly likely. Like our planet, if one small factor disappears, then the tapestry that creates our life unravels entirely.²⁵ Another massive challenge that is explored when it comes to exoplanet detection as a whole is that exoplanets don't emit their own light, unlike stars which can be millions, even billions, times greater compared to them, which is why telescopes nowadays are the only way we can detect planets.²⁶ According to what astroscience has told us so far, there is unfortunately no discovered exoplanet so far to be determined to be habitable for us, but there have been several candidates so far to be discovered in the "Goldilocks Zone" where liquid water is permeated, such as Wolf 1069 b and Gliese 12b. It had also taught us what conditions on planets proves that is hostile or welcoming for human habitation, such as thicker atmospheres from mini-Mercuries being unwelcoming due partial gas pressures leading to potential toxicities and psychological damage.²⁷ Furthermore, tidal locking is slightly more confusing to unpack because while it can be hard for different life to integrate due to how different their survival conditions are based on what side of the exoplanet they live on, one scorching hot facing the sun constantly, the other freezing cold never facing the sun, it also provides benefits that could allow habitability such as preventing extreme conditions and could even offer more stable climates by reflecting intense starlight. Where once planetary habitability was philosophically judged, modern astroscience builds on centuries of astronomical observation and Earth analogues, showing an evolving understanding of environmental conditions necessary for life. In conclusion, similarly to what it has taught us about our understanding of extraterrestrial life and our progress in identification of such, astroscience has played an astronomical role in helping us discover more planets across the universe that could have the potential to be habitable, by allowing us to understand what conditions truly make living on planets possible and how much each one permits. However, it also gave us multiple questions we are still seeking answers for, such as if these conditions are actual proof or just guidelines, if there are any more factors, we have yet to learn about that determines a planet to be habitable. On top of this, there has yet to be a discovered exoplanet that is habitable, even if a greater source of answers has been provided to us by astroscience. But if there has been anything astroscience has proved to us about the identification of habitable planets, it's that it disproved its philosophy and that with discoveries occurring at frequent rates, it is now a scientific possibility that might not be too far from becoming a reality.

The essay so far has harnessed evidence across many different periods of time to explore the correlation between the evolution of astroscience and our understanding of alien life and other habitable planets. In the 1st century BCE, we had a skeletal understanding of astroscience, using our basic knowledge and describing how our celestial bodies are all composed up of an infinite void of indestructible atoms moving all around us.²⁸ This reflects early atomist cosmology, demonstrating the speculation of how multiple world predated modern science. Although the concept of alien life and other habitable planets were believed to stem from more religious grassroots, which Islam and Hinduism have explanations for, it ultimately still had science involved in it. If we flash forward to the 19th century, scientific concepts were far more nuanced and our understanding about astroscience has greatly increased, with some sceptics being made as to if such is even possible given the conditions of Earth.²⁹ And in modern day, this is where our understanding about the science of space has peaked, to where actual discoveries of exoplanets have been made, where conditions such as tidal locks and super Earths came into practise and the complexity of life and our understanding on what life truly means slowly starting to become more clear to us with increasing studies on likely alien biodiversities.³⁰ It is no secret that astroscience has played a significant role in allowing us to identify alien life and other habitable planets all throughout our periods of history due to how our increase in its studies has answered many questions we have had such as if it even exists and what proof we have of such. Yet it was also useful in stemming many more questions for us to answer such as what alien life might look like or where else they could possibly be. But the question of how far astroscience progressed us to identify habitable planets and alien life is a complex one. It could be argued that it has got us to this present day extremely far, further than we could have anticipated, due to our discoveries of evidence snippets daily and the discovery of exoplanets allowing us to deduce its conditions and its suitability for human life, as well as what potential alien life on these planets could have looked like in these conditions. On the other hand, it might not have got us as far as we wanted because despite raised hypotheticals that could be backed by scientific evidence and technological limitations as well as human speculations and speculative data and proof made up by the public also stirs up ambiguity regarding the field. But regardless of sides, one guarantee is that we can certainly use our knowledge of astroscience right now to push us further to reaching breakthrough discoveries. Surprisingly, although scientists might cast religion into the category of speculation due to the lack of provided scientific evidence for its claim, it inarguably has parallels to already established astroscientific concepts used. For example, Hinduism describes the existence of a multiverse where there is an infinite amount of Brahmandas (universes) each with their cometary physics, stars and galaxies and how there are millions of species throughout the cosmos each existing in different dimensions, shining the Fermi Paradox into question where if such were true and there truly was an infinite amount of life forms across an infinite amount of galaxies and universes, why have we yet to find any?³¹ In Islam, the Qua'ran declares that "We made from water every living thing" and prioritises the importance of water in our life, its symbolism of purification, healing and charity, how such is a source of life, which is highly reflective on our understanding of the Goldilocks zone, where exoplanet k2-18 b has been discovered, where temperatures are just right for liquid water to be permeated, where such is mandatory for life to exist.³² This demonstrates for astrological thinking has historically existed within both scientific and religious traditions. And although the chances of such happening is relatively rare, in 2014, an interstellar meteor detected by U.S. government satellites was discovered to be half a meter wide and released a large of percentage of energy in comparison to the atomic bomb which hit Hiroshima, and as it was going too fast to be solar bound, it implies that this object was of interstellar origin, possibly Voyager debris that may have came from another civilisation.³³ In regards to this claim, further proof came from the 2023 Pacific Expedition where near Papua New Guinea, the U.S. space command confirmed that there was a 99.999% probability that it was indeed an interstellar object, as collected magnetic spherules discovered that at least 10% of the object was chemically anomalous as it was highly rich in uncommon elements such as beryllium, lanthanum and uranium.³⁴ These fractions of evidence told us that alien life could be out there and the Kardashev Scale and Drake Equation can be used to indicate the existence of other civilisations, some even holding power of the stars and galaxies, beyond humanity. On top of that, based on discovered conditions that exoplanets enabled scientists to understand what adaptations life on exoplanets could have had, their biological structures, based off of them. Based on Earth's current conditions, super Earths with higher gravity and denser, thicker atmospheres, hypothetically could have had more creatures which have features that can allow them to fly and flying would be easier since there are more air molecules for wings to push against, making lift easier to generate.³⁵ Furthermore, planets that are tidally locked tend to have violent winds due to the extreme temperature differences, which raises the theory that the organisms that may have dominated around these areas are pentapods because their low centre of gravity result in better balancing in these high winds, as well as possibly bioluminescent organisms in the darker zone as emitted light can attract mates, confuse predators and enable communication.³⁶ Moreover, similarly to carnivorous plants on Earth, space plants could get energy by luring insect-like creatures to consume them, where their colours will be different due to light wavelengths on their planets.³⁷ But once again, these are purely hypothetical and based on the anatomies of creatures on our Earth., which might not be accurate to the actual species that could live there. Current technology which we already have, such as the James Webb Space Telescope, uses universal infrared to detect the atmospheric composition of exoplanets, but there are some limitations to this such as missing visible light details in comparison to Hubble as well as being forced to have its beryllium-plated gold hexagonal rings to be kept around negative 400 degrees Fahrenheit for optimal performances. Unlike 17th century telescopic astronomy, 21st century infrared spectroscopy enables atmospheric composition analysis across interstellar distances. Furthermore, SETI, which listens for radio and laser signals from intelligent life and is considered to be one of the most powerful detection devices which may finally disprove the Fermi Paradox, yet its limitations remain clear in that it never had any successes and largely searches for technosignatures that are friendly with human technology, which may be unreliable due to our lack of knowledge regarding the technology of bio-intelligent life in other planets. Nevertheless, the Cold War context of radio astronomy shaped the early methodology of SETI, reflecting assumptions about technologically communicative civilisations. So therefore, what we can conclude from the evidence brought about us, what astroscience led us to know so far about extra-terrestrial life and other habitable planets is that they support the possibility of such not being an impossibility and based on our studies right now, we have discovered potential conditions exoplanets inhibit and what biological structures life could have upon it if it were discovered. It also taught us that we still have a long way to go before discovering any sign of alien life, especially due to how human intervention made astroscience a more speculative topic as our perception of aliens based on how we culturally portray them in movies or fictional works are the first impressions many of us get of them.³⁸ On top of this, many scientific claims about alien life that has been made on alien life so far, although well backed up by scientific claims, still fall under speculation as there is a chance that our understanding could be slightly more erroneous than we believe. But nevertheless, astroscience enabled the search to continue with passion, belief and hope for possibility.

In conclusion, astroscience has most definitely played a substantial part in enabling the identification of extraterrestrial life and other habitable planets. But despite this, the process is still not perfect due to how we don't know if we can trust our findings to always be correct. The technology we have made to capture light and radio waves might not always receive every transmission down to the last detail. And even if scientists consistently scan the perimeter of our world every day and get all different sorts of theories and hypothesises, the probability of those being true could either be maximal or minimal. And this leaves an important question: what could we possibly do to fix these issues, to make astroscience more efficient than it already is? In regard to this question, the two main leading issues are human speculation and technological limitations, so it's a matter of working to reduce them to as little as possible. For example, instead of using solid gold-plated beryllium hexagonal plates on the James Webb Telescope to capture infrared or radio signals, using liquid mirrors held in shape by surface tension in microgravity, mirrors can be built up to 50 metres in diameter and can be more reflective. The only problems in regard to this is keeping the shape and stability of the liquid mirrors in Earth's surface tension, and current levels required for maintaining magnetic fields is very high which is relatively costly and makes the concept sound less feasible. Furthermore, AI can also be used to model and correct any optical distortions such as stellar contamination in order to restore as much full image clarity as possible, allowing to recognise the conditions of exoplanets to determine if it can habituate humans more accurately. And when it comes to human speculation, though this is a smaller issue in comparison to technological limitations, it's still one that many fall for, and with the rise of generative AI being used by a minority of the public to spread misinformation and its quality ever increasing, it makes it harder to separate fact from fiction. Therefore, there is to be a certain rule in regard to sources of research, supposed "proof" is to be checked using AI checkers to search for AI generated imagery or findings. This is also to be done to avoid as much misinformation as possible but also to ensure that greater public understanding is intact. This reflects a historical pattern in astroscience: each technological advance, from Galileo's telescope to the James Webb Space Telescope, has expanded the scope of inquiry and redefined human understanding. While the invention of the telescope in the 17th century marked a turning point from philosophical speculation to observational astronomy, SETI's emergence during the Cold War reflected a technological optimism rooted in American scientific dominance, and its assumption of radio-based communication revealed an anthropic bias in Cold War scientific culture. When it comes to sources as well, although they are some of the most prone for misinformation or alleged truths being inputted into it, it's argued that exhibits from museums are the strongest to go off of as they are expected to give information from actual scientific data, unlike weaker books, articles and documentaries which anyone can write or create and might be realistic enough to be passed off as true information, even when it isn't. Even if identifying what is real and what is false in media is quite obvious through fictional and non-fictional works, there are still some who may believe what they see to be the truth. But that is another question that is posed, what according to astroscience is the truth about extraterrestrial life and other habitable planets? A lot of scientific concepts that we have come about have parallels with religion, but since religion is a faith rather than pure fact, could we even consider what it says to be true? Is what we have claimed even true, since given that aliens could be completely different despite having similarities to human biology and could possibly have different architectures, technologies and living conditions compared to us? How can we know for sure what to do given our lack of knowledge regarding how alien civilisations actually function? Astroscience is evolutionary and never truly stays consistent, but it evolves in ways that gain us greater understandings in even the most minute details. There are several reasons as to why this is a science fuelled simultaneously by passion and research: to find a greater supply of resources given Earth's growing population causes current limited resources we use for energy to be depleted even quicker but also, from a historical standpoint, despite us inching closer every day to eventual discovery, the moment we do find any form of alien life or a habitable planet will be something never seen before in human history, a monumental achievement by humanity. So even though it may not have got us the furthest with the identification of potentially habitable planets and extra-terrestrial life, it still played a major role which, up to today, is laying down the foundations for it to carry on educating us about life, where it can eventually lead us to what we have been longing for after eras of research, a journey at last fulfilled.