Evidence of the presence of iron-eating microbes that existed in the infancy of the earth can tell where and what to look for in life-detecting operations.
This week, researchers announced the discovery of fossil remains, which may be the most ancient example of life on Earth.
An analysis of rock fragments from a rare, primitive part of the oceanic crust has revealed micron-sized pipes and filaments. These are believed to be the remains of iron-eating bacteria that existed between 3.8–4.3 billion years ago. They are believed to have been located in hydrothermal springs on the ocean floor.
The find pushes the modern record of the appearance of life to several hundred thousand years. At that time, the Earth could not be the only cosmic body supporting one form or another of life.
Scientists have gathered strong evidence that on Mars there once were water basins and even possibly vast oceans, as well as a thicker atmosphere and all the chemical ingredients necessary for the development of microbial life. “Unlike Earth and even Venus, there are significant areas on the Martian surface that are very well preserved and provide excellent conditions for finding a habitable environment and bio-signatures,” said planetary scientist Jeffrey Johnson of the Johns Hopkins University of Applied Physics. Lorele (Maryland).
Evidence in the new study may “become analogous to sedimentary systems on Mars, where we see silicon dioxide and iron oxide,” added John Grotzinger of the California Institute of Technology.
Grotzinger, a former leading scientist at NASA's Curiosity mission, noted that the rover is exploring similar conditions in the formation of Murray - the geological layer of the Gale crater, formed from the bottom of lake mud sediments.
“This is great news for Mars,” said Grotzinger.
The discovery of ancient life thriving in hydrothermal vents also increases the prospect of life in the oceans, buried under a thick layer of ice, spanning several moons of Jupiter, Saturn, and other giant planets in the outer solar system.
Europe Jupiter and Enceladus Saturn is believed to contain salty oceans in contact with rocky cores - the same chemistry and environmental conditions that may have caused the birth of earthly life. “Given the new data, ancient submarine hydrothermal ventilation systems should be considered as potential sites of the origin of life, as well as primary goals in the search for extraterrestrial life,” writes doctoral student Matthew Dodd.
Although there is no evidence that extraterrestrial forms will be similar to ours, but at least the starting point has appeared.
“We know how to turn life on Earth into a testable hypothesis,” said Sean Domagal-Goldman, astrobiologist at the Goddard Space Flight Center at NASA in Greenbelt.
“The most famous alien biosphere that we have is the ancient Earth,” he added. “Now we can understand what signs of life could be present on the Archean Earth when there was no oxygen in the atmosphere.”
