By Greg Botelho, CNN
(CNN) — Deep in a remote, hot, dry patch of northwestern Australia lies one of the earliest detectable signs of life on the planet, tracing back nearly 3.5 billion years, scientists say.
At that time, the Earth — relatively speaking — wasn’t into its adulthood yet. Scientists estimate the planet formed roughly 4.5 billion years ago; minerals known as zircons, indicating water, and continents existed within 100 million and 200 million years after that on what was still a scalding planet.
The existence of water suggests that life was possible. But what did it look like, and when did it start?
The discovery from the Dresser Formation, a much examined outcrop of rocks in Western Australia’s Pilbara region, documented in a paper published online this week in the Astrobiology journal may help answer those questions.
It centers on something called microbially induced sedimentary structures, commonly shortened to the acronym MISS. It’s a mouthful to many, but some scientists believe this phenomenon could be the key to finding the first demonstrable evidence of life.
A MISS forms via a process involving microorganisms (found in what’s called microbial mats) with rocks (or sediment), something that can only happens under certain conditions.
Featured image: Pilbara, Western Australia