Earth is believed to be about 4.5 billion years old, but recent studies by researchers claim that our green and blue planet could have sustained life much earlier than we originally thought.
A team of scientists from UC Los Angeles have found evidence in the form of biogenic carbon in a 4.1 billion-year-old graphite sample that was encased in a piece of zircon, which is a type of crystal. Zircon is among one of the oldest samples of material found on Earth, according to Uncover Michigan.
The research team, led by Elizabeth Bell, claims that the evidence pushes back the arrival of Earth's first living organisms to 300 million years. The carbon was procured at Jack Hills of Western Australia and has an isotopic ratio that has been well established to be associated with organic matter.
"On Earth today, if you were looking at this carbon, you would say it was biogenic," she said. "Of course, that's more controversial [for something so old]," Bell said.
One can only record the existence of life by analyzing Earth's rock, which is extended only up to 4 billion years. Hence, if one wanted to go back further, they would have to analyze the mineral deposits within the sediments of the rock, KRWG News 22 reported.
The team had studied more than 10,000 zircons found in molten rocks. They had discovered that 656 zircons contained dark specks that could uncover the truth. They took 79 of these zircons and analyzed them with Raman Spectroscopy, a technique that shows the molecular and chemical structure of ancient micro-organisms in three dimensions.
One of the 79 zircons contained graphite - pure carbon - in two locations, which also contained a characteristic signature, specific in ratio to carbon-12 and carbon-13 which indicated photosynthetic life, according to Fox News.
The researchers concluded from this that life existed before the massive bombardment that had occurred 3.9 billion years ago and caused the craters on the surface of the moon.
The team's findings were published in the journal Proceedings of the National Academy of Sciences.
