Scientists just discovered the oldest evidence of life on Earth proving, once again, there is still a lot to learn about this planet. The fossils that were found in Australia are almost 3.5 billion years old. This discovery could help researchers understand how life started on this planet. With that knowledge, scientists can even pinpoint the perfect spot where we should search for life on other planets.
Life Started Evolving on Land
The Australian fossils that were found suggest that life on this planet started in freshwater hot springs, on land. Not on deep-sea hydrothermal vents as the cannon dictated. This is the oldest evidence of life on Earth. Scientists provided more information about this discovery in the journal Nature Communications.
Until now, researchers based their studies on the rock formations that were found in Greenland. These fossils were 600 million years younger than the Australian fossils that were found now. To date the remains, researchers used a radioactive decay technique that is based on unstable isotopes which were found at the site. To put it in other words, researchers looked for radioactive minerals on the site and managed to date the remains.
At first, scientists believed the location of the Australian fossils had been filled with shallow water. The evidence showed that it might have been the home of a volcanic hot springs system as the fossils contained deposits of geyserite – a material found in hot springs environments.
All of the findings suggest where to look for life on Mars. NASA is trying to find the best place to land the rover 2020 Mars Exploration Mission. One of the places they are considering is a hot spring setting. That location is about as old as the Earth. Despite this fact, researchers mentioned that comparing life on earth with life on other planets based on the Australian fossils might not be such a great idea because every planet is different.
“If you’re going to look for life on Mars, we know it was preserved on hot springs here on the ancient earth. So there’s a good chance if it ever developed on Mars, then it would probably be preserved in hot springs there, too,” mentioned Tara Djokic, one of the researchers.
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