Fulgurite, a rock formed when lighting strikes the ground, may contain phosphorus, they say:
Phosphorus is essential to life and plays a key role in all life processes from movement to growth and reproduction. The phosphorus present on early Earth’s surface was contained in minerals that cannot dissolve in water, but schreibersite can.
Mr Hess, now a PhD student at Yale University, Connecticut, USA, said: “Many have suggested that life on Earth originated in shallow surface waters, following Darwin’s famous “warm little pond” concept.
“Most models for how life may have formed on Earth’s surface invoke meteorites which carry small amounts of schreibersite. Our work finds a relatively large amount of schreibersite in the studied fulgurite.
“Lightning strikes Earth frequently, implying that the phosphorus needed for the origin of life on Earth’s surface does not rely solely on meteorite hits.
“Perhaps more importantly, this also means that the formation of life on other Earth-like planets remains possible long after meteorite impacts have become rare.”
The team estimate that phosphorus minerals made by lightning strikes surpassed those from meteorites when the earth was around 3.5 billion years old, which is about the age of the earliest known micro-fossils, making lightning strikes significant in the emergence of life on the planet.
Furthermore, lightning strikes are far less destructive than meteor hits, meaning they were much less likely to interfere with the delicate evolutionary pathways in which life could develop.University of Leeds, “Lightning strikes played a vital role in life’s origins on Earth” at ScienceDaily
The paper is open access.
But then a question arises: There are plenty of lightning strikes. Why isn’t life always coming into existence? Why does it only ever come from previous life?
See also: The Science Fictions series at your fingertips – origin of life What we do and don’t know about the origin of life.