In an age when the Earth has been charted from the Old to New World, it almost seems like the times of great voyages of exploration and discovery have long since passed. This holds true, so long as you don’t look up at night. On a clear night it becomes painfully clear that there is much more to discover; an entire universe filled to the infinite brim with secrets waiting to be uncovered. The age of exploration hasn’t passed, it has simply moved upwards into the never-ending sky, with astronomers at the helm.
In astronomy, countless voyages are undertaken, not by humans, but by light. Light can travel for billions of years at the fastest possible speed of 300,000km/s, covering distances so vast and witnessing wonders so grandiose, that any Earth-bound adventure would be put to shame. It is an astronomer’s job to greet the courageous light at the end of its journey with telescopes and listen to the stories it has to tell. Decoding the tales of light is the essence of astronomy. It is with these tales that astronomers can explore the universe and uncover hidden wonders.
In recent times, the great tales told by light have led to the discovery of new kinds of “New Worlds”. Instead of continents, these “New New Worlds” are worlds around other stars, or exoplanets. Once a rare discovery, exoplanets have become a common phenomenon with the advancement of telescopes such as the Kepler space telescope. To date, 1932 exoplanets have been discovered by Kepler, with another 4696 yet to be confirmed, and an untold more yet to be discovered. The sheer number of known planets, however, doesn’t devalue discovery. Each exoplanet is a world. It has an environment, it has a history and it has a future.
Astronomers have discovered a world which rains glass, one with rings 200 times larger than Saturn’s, a planet with two stars (just like Tatooine), a world orbiting a neutron star (the remains of a massive star), and even a planet being blasted away by its own star – but while this list of eccentricities grows alongside the list of exoplanets, so far no other planet is known as “a world with life”.
Today, astronomers are trying to find light that will tell us of another inhabited world. The first step is finding worlds similar to Earth; small enough so that they are not a gas giants, large enough so that they have atmospheres, and not too hot or cold so as to ensure they exist in the Goldilocks zone where liquid water can exist on the surface. Kepler has found just 12 planets in the Goldilocks zone that are no more than twice the size of Earth ‒ 12 planets that may have life.
Beyond the hunt for new worlds close by, when telescopes are cast towards the far reaches of space, astronomer’s decrypt equally fantastic stories from some of the oldest and greatest voyaged of light. Far off in the universe, where light has travelled millions to billions of years to reach us, the universe is littered with galaxies. Enormous collections of billions of stars in all shapes and sizes are scattered about the black sea of space. In these far off galaxies, like seen in the Hubble Deep Fields, civilisations may have flourished, catastrophes may have occurred and empires may have fallen – but we will never know the stories of the stars and planets in the far off galaxies.
Despite this boundary to discovery, the stories we have been told, and the sights shown to us by the voyages of light are unending. I have not even begun to scratch the surface of what astronomers have learnt, or will learn, from light.
The age of exploration and discovery never ended. Above us awaits a universe of new worlds to discover and understand. One day it may be humanity who venture forth on a great voyage, called onward by curiosity and perhaps to a new world around a new sun.
The age of exploration never ended – the open sea lies above us with new worlds to be known.