Carl Sagan once said that he preferred science to science fiction. Why? Because science is stranger. This idea is the very reason this blog exists. And you can’t really get any stranger than the enigmatic enormity that is space.
Space makes us all philosophers. Mankind has always had a fascination with it, and gazing starwards almost always induces a sense of profound, contemplative wonder (and a mild sense of humbled insignificance). It puts us on a pursuit for truth and knowledge, and makes us ask big questions about humanity and the universe. Major advances in mathematics and physics have attempted to explain what we see in the night sky, but it seems they just generate new uncertainties.
Astronomy as a field is ever approaching the truth, but the truth always remains just out of reach. One of the big questions about space (and one that has been done to death in Hollywood and popular media) asks whether or not we are alone in the universe. Does life exist elsewhere? Of what nature? Is it intelligent? Is it like us, or is it more like something – for the lack of a better word – alien?
Astrobiology is a field within astronomy which seeks to discover whether life exists in the universe; its origin and evolution; and how we can detect it if it does exist. As such, it’s a pretty inter-disciplinary field and integrates elements of physics, chemistry, molecular biology, geology and ecology. In 1961, an astrophysicist by the name of Frank Drake devised a complex mathematical equation which calculated the probability of extraterrestrial life, by taking into account things like the rate of star formation, the fraction of stars without planets and the fraction of planets with suitable conditions for life. He found that the probability that intelligent life exists elsewhere in the universe is incredibly likely. But even without this equation, consider:
- Our star – the sun- is just one of trillions in the universe. Trillions. Ponder the immensity of that number for a moment. It’s unfathomable.
- Stars generally have more than one planet.
- Many recently discovered planets are within the Goldilocks zone: close enough to their sun that they’re not deathly cold, but far enough away that they’re not burned to a crisp. This allows liquid water to exist on their surfaces, which is widely considered to be one of the precursors and requirements for life.
Given the above, it seems absurd and dangerously anthropocentric to think that we’re the only life-forms out there. So what should we be looking for? Although the search for habitable planets and environments is important, a large part of astrobiology focuses on gaining an understanding of the beginning of life where there was once nothing. And the best way to do this is to examine the rise and evolution of life on our own little pale blue dot. 🙂
The question of the origin of life is still very much in contention, however there are some feasible theories put forward. These will be explored in future posts.
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