Is Our Universe As Quiet As It Looks Like?
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“Landing confirmed. We are safe on Mars,” the phrase stated excitedly when the Perseverance rover landed on the Red Planet. Since November of 1964, with the launch of Mariner 4 that flew by Mars in 1965, NASA has been developing methods to further explore the Red Planet. This sparks the question: Why is NASA exploring Mars? There can be many reasons, including finding new environments for humans to live in, but undoubtedly, the most important reason they or in fact, any other space agency or organization is exploring Mars and other planets is to discover an answer to the Big Question: Are we alone? The article is going to explore the progress that has been made to discover extraterrestrial life in or outside our solar system and the mysterious questions that are tied with such discoveries.
According to NASA’s database, more than 4,400 exoplanets have been confirmed, with some of them existing in the habitable zone of their star. For instance, Kepler-22b is an exoplanet orbiting a Sun-like star, Kepler-22, in its habitable zone, which means that it has the potential to sustain life. The habitable zone or Goldilocks zone refers to the belt around a star that provides the right temperature for liquid water to exist. Whether a planet exists in the habitable zone is one of the criteria astronomers are using to discover life. Astronomers concluded that humans can not yet contemplate any other form of life that is not similar to ours, therefore, the best way to search for extraterrestrial life is through a principle that we are already familiar with, which is that life requires liquid water (H2O), and water will not exist without the right temperature. Kepler-22b was discovered in 2011 and since then, further research has been done that is increasing the probability of discovering other civilizations.
Conceptual Illustration of Kepler-22b (source)
According to a new publication in The Astronomical Journal, researchers from NASA and other corporations estimated that there might be more than 300 million planets orbiting their star in the habitable zone. The astronomers used the size and age of the star that the planet is orbiting and the radius of the planet itself, in addition to the planet having to be in the habitable zone as requirements to filter planets that are suitable for life. The requirements stated above allowed researchers to find planets that are in a similar situation as Earth. That is because Earth is currently the only planet that living organisms are existing on, and with that, even though the astronomers filtered out the number of candidates based on the requirements, there are still millions of planets similar to Earth, which indicates how vast the cosmos is. Millions of Earth-like planets pose the possibility for millions of alien civilizations, however, this leads us to wonder: Why is the universe so quiet?
With all these possibilities for extraterrestrial life, indicated by the number of planets in the whole universe, why is there no evidence of alien life? Enrico Fermi, the physicist who conducted the Fermi Paradox “grasped that any civilization with a modest amount of rocket technology and an immodest amount of imperial incentive could rapidly colonize the entire Galaxy,” the Search For Extraterrestrial Intelligence (SETI) Institute stated. The Fermi paradox seeks to answer the question of where aliens are. The universe is an estimated 14 billion years old while Earth and our solar system are only around 4.5 billion years old. Earth and our solar system are fairly young compared to the older solar systems. Astronomers inferred that there are presumably civilizations far more advanced than ours that have potentially achieved interstellar travel even before our solar system came into existence. Taking into account that there are trillions of stars in the universe, with each one having at least one planet orbiting it, the possibility for advanced alien civilization is very high and yet, there is no factual sign of them. Experts theorized that aliens should have visited Earth already, so where are they?
To conclude, there is still a high probability that extraterrestrial civilizations exist, however, the Fermi Paradox reminds us to be grateful for what we possess. With all the progress that has been made, there is still a chance that Earth is the only planet that can sustain life, meaning that humankind might be the only civilization that has ever existed. Earth has to be greatly taken care of since it might be the only of its kind.