Surely someone must know what life is, I thought to myself when I first heard of this in 2003. It must be a definition somewhere. I started looking for it. Textbooks describe life based on what it has or does. It grows, it reproduces, it has ability to adapt and it has metabolism which gives it energy from chemical reactions. I learned all these but not found a definitive answer to the definition. Scientists still argue about this in 2020.
The closest that we came to one was in early 1990’s when a NASA advisory panel to the astrobiology programme came up with a working definition:
Life is a self-sustaining chemical mechanism capable of Darwinian evolution. NASA Astrobiology
A couple of years later, designing an astrobiology panel for our space museum I faced the same question: What is life? I also just found out I was pregnant. My journey to produce an answer turned philosophical. A tiny amount of cells were growing into another living being. All happening inside me. I enjoyed the research process tremendously. I would read my findings out loud to my to-be-daughter, we both shared the same office; we would marvel at live’s resourcefulness, adaptability, ability to make energy, reproduce but also to compartmentalise and be alone — these are the pillars of life. Alone in our office we would listen to music and research about aliens. By the time she emerged into the world, I had the answer:
Nobody yet knows for sure what life is.
When she arrived, on a Full Moon evening, it was the most magical moment I had experienced in my life. Whatever its definition, life was overwhelmingly beautiful.
A couple of years later, I started working for a government department. Stationery was highly prized and travel scheduled on a budget. The OIA was always floating on top of every decision we made. You cannot hide from the OIA. How can they hide the spaceships then? And with all the budget cuts, where would they find money to do so?
My evening job, at the planetarium, had many encounters of the third kind with various concerned citizen who still demanded to know where the aliens were. We didn’t know either. Simple calculations, the distance from here to the nearest star, Proxima Centauri is 40,208,000,000,000 km. Light, the fastest traveller, takes in average 30 minutes to come from Jupiter, about 800 million kilometres away. From Proxima Centauri, light takes 4.35 years to reach Earth. We cannot travel at the speed of light and there might not be aliens in there. Proxima is a really angry flare star that blasts its planets in lethal radiation. The closest habitable planet could be, however, KOI-456.04 at about 3,000 light years away. Despite its fish-like name, it orbits its star, Kepler -160, in the habitable zone. This is where is not too hot and not too cold but just right for life to appear. Just like here on Earth. So far Earth is the only place we know to have life.
When Voyager turned around and took the Pale Blue Dot picture in 1990, humankind saw a dot. There is no more sobering realisation than how vast the distances in space are and that’s what science can do to you. The more you know the less other people can BS you. Science is the greatest tool our brains created.
We live on a dot. Dinosaurs lived on the same dot but they are not here anymore. They did not have science or a space programme, not even a tiny one like us. We are so lucky to be alive. There were five major life extinction events before us, in the 3,5 million years of life officially existing on Earth, in which 50–90% of the species at the time died. Was it divine intervention? It’s easier to blame everything that happens on the stars and disasters on comets. To hide behind fate, religion and destiny, and never take responsibility for life.
Do you wish to meditate about the meaning of life? Try this:
We don’t know what life is.
Do you believe that after we terminate our metabolic activities here on Earth, will we have another chance to correct our shortcomings and failures? What if there isn’t? What if right here and now is the only chance we have to live? What would you do right now if that were true?
Do you feel alone? I did many times before becoming serious about astrobiology. I learned there know how special we are. We are the only life we have met. And every life on this Earth of ours is precious. What’s the future of humankind going to look like?