The search for life on other planets is a massive deal. Even finding the most simple of cells from another world would be monumental. It would give us an insight into how life forms on other planets that would slingshot our scientific knowledge.
But how do we know life exists? I mean it’s not like we have proof. scientists don’t even know for sure how we ended up with life on our planet.
Arthur C. Clarke once said: Two possibilities exist, either we are alone in the universe or we are not. Both are equally terrifying. Very profound. I mean it’s quite bleak to think we don’t have any cosmic neighbours but by the same token… you’ve read War of the Worlds, right?
Of course, there are actually three outcomes when it comes to life. Either life is common in the universe, life is rare in the universe or we are unique! But which is it? Famous astronomer Carl Sagan theorised there could be up to 10,000 advanced civilisations and that’s just in our Milky Way!
Others think this is bunkum many believe that an Earth-like planet would be needed to sustain life and that planets that fulfil this criterion will be incredibly rare. But who is right?
Nasa seems to believe that Earth-like conditions on a planet will equate to life existing on that planet. People have been critical of this stance including astronomers and astronauts, suggesting it is a marketing ploy.
So what can we take from this? There may or may not be life elsewhere. Doesn’t really help us does it? Either of those options may have scared Arthur C Clarke but scientists are excited by both.
Will we know?
The reason for the optimism is that NASA is on a “mission” if you’ll pardon the phrase. They are spuriously exploring exoplanets (planets that orbit stars outside of our solar system) they are doing this through satellites like Kepler and Hubble etc. So far 21 planets have been found in what’s referred to as the “Goldilocks zone”. This means that they are an appropriate distance from their star so that they aren’t too hot or cold (yeah, they are just right!) Perhaps the most famous of these is Trappist-1, a mere 40 light years from earth.
That planet is to be the focus of the upcoming James Webb space telescope (JWST). When it launches in 2021 it will be powerful enough to analyse the atmospheres of exoplanets to look for tell-tale signs of life.
The devices on the JWST mean that we will be able to see the atmospheres of these distant planets. Using our technology we should be able to detect chemicals associated with like such as ozone and methane. These are usually only present when there is organic life.
Whether they find an atmosphere on Trappist-1 or not it will still be exciting.
Also on the hunt for little green men will be the Transiting Exoplanet Survey Satellite (TESS). Launched in April. This will track down other exoplanets. This, like Kepler, will scan for planets in the Goldilocks zone but will look at stars far closer to earth than Kepler.
Following this in the mid-twenties will be WFIRST a space telescope a hundred times more powerful than Hubble. So as you can see NASA is going “all-out” to see if those planets have life or not.
Of course, scientists just want to know the answers. If they find signs of life on the planets then that gives us proof, but if they study all the nearby exoplanets and find no signs, whilst that doesn’t mean there is definitely no life in the universe it would certainly suggest that if there is that it’s incredibly rare.