“Space, is big. Really big. You just won’t believe how vastly, hugely, mindbogglingly big it is.” It doesn’t take much contemplation to realise that in this simple line, Douglas Adams actually nailed the nature of the Universe. While we may have made a few leaps from believing that the Sun revolved around the Earth–including one pretty impressive leap to the surface of the moon–human science is far from educated about the expanse of space that lies beyond our galaxy. This unknown has captured the minds of writers, scientists, artists, philosophers and conspiracy theories for centuries, so every time a new fragment is revealed the infinite jigsaw becomes just a little bit clearer. The next phase of this intergalactic learning curve began yesterday, as NASA sparked a wave of excitement by announcing the discovery of seven Earth-like planets orbiting a nearby star.
Now of course, in space, ‘nearby’ stands at a whopping 40 light-years (235 trillion miles) away in the constellation Aquarius, but it’s still the first time any system has been discovered with such a striking similarity to our own so we’ll let it slide. These planets are known as exoplanets, a term given to any planetary body orbiting a star outside our solar system, and this particular exoplanet system was first discovered in May 2016. It was during the ongoing International search for Earth-like planets that a team working with the The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile spotted three previously undiscovered bodies which upon further investigation revealed the whole seven planet system. In their honour, this exoplanet system has been christened TRAPPIST-1.
With the help of the Spitzer telescope at the European Southern Observatory, the mass and densities of the first six planets were estimated giving scientists the opportunity to start speculating about their geography. As far as they can tell, although they may be similar in size to our Earth, the terrain on all seven is extremely rocky and the unexplored outermost planet would be iced over. This is because the star, TRAPPIST-1 has been deemed an ultra-cool dwarf star, so cool in fact that it would be possible for liquid water to exist on the planets nearest to it, unlike those orbiting our own sun. They also learned that the seven planets are closer to their host star than in our galaxy, even the last one would be closer than Mercury is to the sun, this would mean that from the surface of any planet you would be able to see the others with the naked eye.
Whether or not these planets are habitable remains to be seen but according to astronomer Michael Gillon who sat on the panel for the NASA announcement, the planets are all well-suited for detailed atmospheric study. In fact in 2018, The James Webb Space Telescope will be launched and will have the ability to measure the chemical composition of exoplanet atmospheres. If the atmospheres show traces of gases like ozone, oxygen, or methane, life could exist there.
This is an exciting time for astrophysics as it provides a basis for so much further discovery as well as reviving the ultimate debate about whether intelligent alien life exists. Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate addresses that query stating “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.” So although NASA is getting constant live readings from Kepler-1 it will take a while to fully understand the system and its nature, and definitely a lot longer to actually attempt to go there. For now we can content ourselves with imagining the limitless possibilities that await.
Featured image courtesy NASA
Words: Shireen Jamooji