The key ingredient in the recipe for life: Lightning5 min readReading Time: 4 minutes
Do you remember the movie Frankenweenie or the world’s first horror novel Frankenstein? If you do, you probably recall that they created life and ended up facing terrifying monsters? But do you remember how they did it?
Yup, they used lightning to spark life. How ridiculous! Well, you may have had to delve into an acceptance of fantasy when you saw those monsters come to life, but it turns out that lightning is, in fact, a key ingredient in the recipe for life.
What! Lightning! Is Frankenstein going to stab me in my sleep?
Well, no, it’s not that simple at all. The lightning needed to create life is about 18 quintillion lightning strikes. (That’s one followed by 18 0s!!!) Also, lightning and life have a slightly complicated relationship.
First, let’s visit the recipe for life:
Are you surprised that you don’t see lightning on there? Well, that’s because lightning was simply a tool that made phosphorous, which is a crucial ingredient in our recipe, available.
Phosphorous is needed for the creation of the DNA and RNA which happen to be the basic building blocks of the living cell. It is also present in ATP, the energy on which the cell runs, as well as the walls of the cell. And what are living things if not simply a collection of billions of cells?
It’s not that the planet doesn’t have enough phosphorous it is just that the phosphorous that we do have is inactive. That means that it isn’t ready to react with all the other ingredients in the recipe for life to spark life in the first place. For phosphorous to be active and available for our crucial reaction, it needs to dissolve in water.
The meteorite answer: Until now, scientists assumed that the phosphorous needed for life was provided by meteorites that crashed into the Earth. The meteorites brought with them a substance called schreibersite that contained active phosphorous. But there was a catch; The Earth would have needed plenty of schreibersite to create and sustain life. However, there just weren’t that many meteorites striking the planet about 4 billion years ago.
So, how did lightning give us access to phosphorous?
Scientists estimate that life was first found between 3.5 and 4.5 billion years ago. At that time, The Earth was warm, and our atmosphere was filled with Carbon Dioxide. There was lots of water and a whole lot of storms. There was an abundance of phosphorous too, the only problem was that it was locked away for good. In fact, there was even quite a lot of phosphorous trapped in unreactive and insoluble rocks. So, the raw material was there but wasn’t available to make life. However, as I mentioned, there were a whole lot of storms rumbling around the planet.
The storms brought lighting with them. Billions of bolts of lightning struck the planet every year, and each time the lighting struck some phosphorous would be freed from the rocks.
How does that happen?
When lightning strikes the surface of the Earth it reacts with the insoluble rocks that contain trapped phosphorous. The reaction produced a a glassy rock called a fulgurite. Fulgurites absorb some of the trapped phosphorous and keep it in their glassy bodies as schreibersites. Since the fulgurites can dissolve in water, the phosphorous in the schreibersite is available to merge with the elements in the water and the atmosphere to finally create life.
What does this mean for life on Mars?
This is great news for our search for life on Mars! The ideal conditions to generate life with the help of lightning would be shallow water. If lightning is to generate enough phosphorous needed for the sustenance of life, it cannot get lost or wasted in the deep seas. Once the phosphorous is unlocked in the shallow water, it has the chance to dissolve in the water and come together with all the other elements around. Then, life may form with all the combined ingredients and the energy of the Sun. This is great news for the search for life on Mars because Mars is definitely not submerged in deep waters. So, if there really is shallow water somewhere on that red planet, there could even be life!