What are Exoplanets?
Since the moment we’ve been able to stand on two legs, we’ve looked to the stars and wondered what lies above our heads. We’ve imagined the possibilities and dreamt of worlds beyond our reach. As our understanding of astronomy expanded, our collective desire to touch the sky was aided by the growing knowledge of our universe.
Whereas our ancestors looked to the stars and wondered about their place in the universe, today we have a rough understanding of who we are. We are the human species, floating on a cosmic speck of dust light years away from even the centre of our own galaxy. However, our universal address line includes an important point of interest – The Sun. Our entire understanding of the galaxy – indeed, the universe – hinges on the importance of our sun and our solar system.
At the centre of our solar system, and countless other solar systems, is a single galactic body – a star for all planets to revolve around. Exoplanets – otherwise known as extrasolar planets – are planets that orbit around any star that is not our native sun.
How do exoplanets work?
What makes exoplanets fascinating is not the fact that they exist, but the method behind their creation. Our own planet Earth was created from an innumerable series of cosmic coincidences. One gravitational tug here, a gravitational pull there, and Earth as-we-know-it would not exist. Within the scope of the universe, however, planets are not difficult to make. All it takes is a tremendous concentration of cosmic dust – normally a combination of a variety of elements – and gravity.
Atomic forces and the force of gravity work in conjunction to form stars, and the massive gravity exerted by stars eventually results in the formation of a solar system. Exoplanets – indeed, all planets – are formed through the same universal forces that created the planets in our own solar system.
Why are exoplanets important?
The question quickly becomes: if all it takes to form an exoplanet is cosmic coincidence, why is the presence of a planet outside our solar system so important? As always, adding to the expansive encyclopedia of human knowledge is the reason most people think exoplanets are important. As a species, we want to know everything there is to know about our universe, and adding exoplanets to the checklist is an absolute necessity.
However, exoplanets are also important for a variety of other scientific reasons.
Our Earth is the only planet in a solar system of – now – eight other planets that is perfectly suited for life; studying exoplanets allows us to learn more about what makes Earth so special – in order to understand how we are able to exist.
Recently, NASA’s Kepler mission catalogued its 1000 exoplanet. The Kepler mission catalogues exoplanets existing in their solar system’s habitable zone – an area of space calculated to support life based on Earth’s own cosmic geometry. Most researchers involved with the project explain that Kepler’s existence enables us to answer the ultimate question: are we alone in the universe?
Frankly, I believe that exoplanets are important because they eliminate a certain amount of human arrogance. For millennia we’ve believed that we’re the centre of a Universe almost 13.8 billion years-old, and the existence of any other planet proves that Earth is not special. This is both terrifying and exhilarating.
What is the future of exoplanets?
There is a future where we colonize other planets. There is a future where we’ll be able to visit other worlds instead of other countries. There is a future where our descendants will look to the stars as a piece of galactic cartography – where 20-year-olds hitchhike across the galaxy instead of hitchhiking across Europe.
As always, I look forward to the truly absurd possibilities. The Kepler mission recently discovered two planets that bear the closest resemblances to Earth that our species has ever found. We will eventually find life on other planets, and perhaps Kepler-438b is where the human species will engage in our first cosmic handshake.