Researchers have found the building blocks of life deep below the seafloor, adding evidence to the theory that life is able to spring up wherever there is water, and of course the right chemistry. The study, published in the Proceedings of the National Academy of Sciences, could have implications for the chances of life existing on other worlds, such as Jupiter’s moon Europa.

The team of scientists, from the Woods Hole Oceanographic Institution (WHOI), Virginia Tech, and the University of Bremen in Germany, studied rock samples that had been gathered from the seafloor off the coast of Spain and Portugal in 1993, originating from 100 million years ago in the Early Cretaceous period. Analysis revealed that the rocks were rich in lipids, proteins and amino acids – the building blocks of life.

It suggests that the interaction of the mantle with seawater can create the potential for life, and shows that life can spring up in a variety of environments. In this particular location, it’s thought that mantle rocks were exposed to seawater about 125 million years ago, causing chemical reactions that transformed the seawater into a hydrothermal fluid 65 meters (215 feet) underground.

That sort of fluid is important because it contains hydrogen and methane, while seawater itself contains dissolved carbon and electron acceptors. “So when you mix the two in just the right proportions, you can have the ingredients to support life,” said Frieder Klein, an associate scientist at WHOI and lead author of the study, in a statement.  

Interestingly, it suggests that the ingredients necessary to foster life can essentially be made from scratch. “Similar systems have likely existed throughout most of Earth's history to the present day and possibly exist(ed) on other water-bearing rocky planetary bodies, such as Jupiter's moon Europa,” added Klein.

However, while this is all well and good, there is still a lot of uncertainty about the biochemical processes that take place at these depths to produce life. Just because there are the necessary ingredients, we still aren’t entirely sure how life starts in the first place. That is one of the biggest and most fundamental questions we need to answer.

But the research is promising. We are finding that water appears to be fairly common on other worlds. In our own Solar System, Mars once had water, some moons such as Europa and Ganymede could have subsurface oceans, and other places have traces of water. Numerous exoplanets with hints of water have been found as well.

If life began in a variety of water-bearing locations on Earth, could it also have done the same elsewhere? That, ultimately, is the question everyone wants to know the answer to.