Until now, Earth’s highly oxygenated atmosphere was credited to all the plant life found on the planet, but now a recent study conducted by researchers from American and Canadian universities has shown that Earth’s oxygen was mostly given by algae, roughly 2.5 billion years ago.
The main purpose of the study carried out by the universities of Waterloo, Alberta, California Riverside and Arizona State, was to clarify if Earth’s oxygen rich atmosphere originated from a main burst of oxygen that came with the evolution of photosynthesis or if it was a gradual process that took a lot more time, the oxygen coming in whiffs throughout the years.
By studying black shale rocks from the coast of Western Australia, researchers have been able to identify a sort of pattern in the quantity of oxygen present in the atmosphere. Samples that were older presented a higher degree of oxygenation when compared to younger samples, thus showing that our atmosphere didn’t become the oxygen-rich environment of today immediately.
The event which triggered the Great Oxygenation Event, the event which led out a high amount of oxygen within our atmosphere, occurred when the continents began to shift, creating large areas of shallow oceanic waters in which a species of blue algae thrived. These algae started to produce a higher quantity of oxygen due to their higher intake of natural resources, thus creating the event.
This event started a complex process that eventually led to an oxygen0rich atmosphere, large quantities of oxygen being whiffed at regular periods until a certain threshold was reached.
The next step in this study will require more samples in order to further clarify the exact dates in which a higher or a lower oxygen amount was present on the planet, so that they will be able to create a draft that shines a light on the process of atmospheric evolution, so that it may be applied when studying earth-like exoplanets.
Science is still a fairly long way from completely understanding how exactly our Earth came to be the planet we know and love today, and even further away from replicating such advanced and complex processes in order for us to be able to terraform other planets. But if science will ever advance to that point, planets like Mars, among others, will be able to sustain life on their own through intense plant colonization across its lands.
Because Earth’s oxygen was mostly given by algae, a terraforming process will be highly dependent on water, but until we even reach a point in which we will start considering extensive colonization of other planets, we at least are discovering more and more about our very own Earth.