By Charles Q. Choi
Extremely tiny newfound habitats hidden within oil could expand the potential for life in the universe, researchers say.
Scientists have discovered microbes living in microscopic droplets of water inside a giant asphalt lake on Earth, suggesting that alien life could perhaps exist within ponds of sludge on distant landscapes such as Saturn’s largest moon Titan.
Researchers investigated the largest naturally occurring asphalt lake on Earth, Pitch Lake on the Caribbean island of Trinidad. Black goo there oozes across roughly 114 acres (0.46 square kilometers), an area equivalent to nearly 90 football fields.
Prior studies had found that microbes could thrive at the boundary where oil and water meet in nature, helping to break down the oil. However, investigators had thought oil was too toxic for life, and that the levels of any water inside the oil were below the threshold for life on Earth.
“Oil was considered to be dead,”said lead study author Rainer Meckenstock, an environmental microbiologist at Helmholtz Zentrum München, in Germany.
Now, scientists find microbes active within Pitch Lake, dwelling inside water droplets as small as 1 microliter, about one-fiftieth the size of an average drop of water.
“Each of these water droplets basically contains a little mini-ecosystem,”study co-author Dirk Schulze-Makuch, an astrobiologist at Washington State University in Pullman, told Live Science.
These droplets contain a diverse group of microbial species that are breaking the oil down into a variety of organic molecules. The chemistry of the droplets suggests this water does not come from rain, but from ancient seawater, or brine from deep underground.