Fossilized remains are a curious piece to the puzzle that fortifies the natural history of our world. These relics provide a glance to the distant past and allow archeologists to continue to speculate the beginnings of life here on Earth. However, for astronomers, fossil evidence opens the doors to the possibility of life existing beyond our atmosphere.
A team of Australian scientists have widened this prospect even further after uncovering ancient fossils, the oldest to date. Following an in-depth analysis, the remains were dated back to 3.7 billion years ago; a staggering 220 million years before life was believed to have emerged. This time is known as the Archean Era.
The fossils were unearthed in an area known as the Isua Supracrustal Belt (ISB), located in southwest Greenland. Scientists were previously unable to reach this region, though rapidly melting ice caused by global warming made it accessible.
They were discovered as stromatolites, or formations composed of layers of sediment piled together by communities of water-based bacteria. These remains were once a colony of microorganisms that thrived on the archaic seafloor, evidenced by the rare marine elements and sedimentary rock found near the samples.
The monumental find has forced scientists to reassess what was preconceived to be the origins of life on Earth and has also brought forth the age-old discussion of life on Mars. As dubious as it sounds, the remains may contribute to speculation of similar structures hidden on the Red Planet.
About 3.7 billion years ago, Mars had a warmer and wetter climate. Encompassing this, it is not unreasonable to say the earliest microbes were able to form just before the planet’s atmosphere was stripped away and its waters ran completely dry.
Professor Martin Van Kranendonk, the Director of the Australian Centre for Astrobiology at UNSW explained, “The structures and geochemistry from newly exposed outcrops in Greenland display all of the features used in younger rocks to argue for a biological origin. This discovery represents a new benchmark for the oldest preserved evidence of life on Earth. It points to a rapid emergence of life on Earth and supports the search for life in similarly ancient rocks on Mars.”