Recent studies suggest that earth could have been hit by life. Literally.
A study recently showed that there is a possibility that a lot of lightning bolts struck the surface of Earth over a billion of years, which could have potentially unlocked crucial phosphorous compounds which may have paved a path for life on Earth.
When one hears this statement, the most obvious question that is prone to pop up is: just a dash of lightning is sufficient to create life?
The answer to that would be- Not really. It’s not as much about that lightning bolt, as it is about the presence of phosphorous. It’s all about the potential things that can be created once organic materials are combined with other bio-essential elements. To demonstrate this, if you take phosphate; which is a combination of oxygen atoms and phosphorous atom, which actually form one of the basic requirements needed to support life by being present in DNA, ATP and RTP, which mostly give energy to the most primary structure of a life form- the cell.
Not only here, but phosphates are found in abundance inside the human body, ranging from the composition of teeth, bones and cell membranes. However, this justifies the possibility of creation of life via this medium. Reeling back, another concern to be addressed can be relating to how phosphorous is found in abundance right now because of human activities. But 4 billion years ago, how was this phosphorous accessible?
About 4 billion years ago, most of earth’s phosphorous was trapped inside insoluble rocks and hence, couldn’t combine into becoming organic phosphorous. While the phosphorous was trapped, water and carbon dioxide content was plenty which makes us arrive to our third big question- How did we get all the components together then?
One among the many theories point towards the fact that earth could’ve gotten its phosphorous content from meteors which carried a mineral called schreibersite, which is composed of part phosphorous and is also soluble in water. The only probable reasoning to substantiate the presence of phosphorous freely in the atmosphere is to attribute it to the fact that a lot of schreibersite meteorites could have crashed into Earth continuously over millions or billions of years which would’ve finally resulted in the release of phosphorous into the atmosphere. Such a release could have created the perfect conditions for biological life.
In this study, researchers show that lightning bolts striking the planet were a significant source of reactive phosphorus on Earth around the time that life formed.
There are other things that help lightning bolts in forming a conducive environment for nurturing life. One bolt of lightning can heat up the surface it strikes up to almost 5,000-degree Fahrenheit (2,760 degrees Celsius), which lead to forming of favourable conditions for organic substances to combine.
Not only this, but this study also examined a lightning-blasted clump of rock, called fulgurite, which was once excavated to be obtained. Further research showed how it had little balls of schreibersite, along with other glassy minerals. This helped in tentatively proving that the hypothesis is not that wrong after all. Once this was proved, new questions were waiting to be explored.
Calculating the Amount of Lightning
One such question was calculating if enough lightning could have possibly stuck Earth to release such elements into the atmosphere. This was calculated using a model of Earth’s atmosphere. While trying to reach a conclusion, various things were taken into consideration. At present, almost 560 million lightning bolts strike the planet however, this number would’ve been a lot higher 4 billion years ago when Earth was rich in Carbon and water. The potential number could be around 100 million-1 billion bolts.
This number is actually a very huge range. Most of the study is based on assumptions about the prevailing conditions on Earth at that point in time, but the most astonishing fact still remains that even the lowest quantity of phosphorus could have made a difference for the emergence of life!