The mystery of what may lie at the center of the Earth (if anything) has fascinated humankind for centuries. From Dante’s Inferno to Jules Verne’s classic and influential 1864 sci-fi novel Journey to the Center of the Earth, our imaginations have run wild with fanciful images of what could lie deep within our planet. Even Alice in Wonderland is essentially a tale of a subterranean journey into a strange, alien land (Carroll’s original title was Alice's Adventures Under Ground). While outer space continues to be the main destination for human exploration, scientific research into the deep Earth is showing that there are likely still worlds unknown hidden deep underground here on our own planet.
Just this week, scientists from the Netherlands’ Utrecht University announced that they may have detected traces of life some 10 kilometers (6 miles) below one of the deepest places on Earth: the Mariana Trench. Their research has been published in the Proceedings of the National Academy of Sciences.
According to their data, researchers discovered lipids and hydrocarbons in samples of minerals collected from a mud volcano on the seafloor near the Mariana Trench. These compounds are usually only created as byproducts of biological processes by organisms like microbes. Oliver Plümper, who led this research, says the presence of hydrocarbons and lipids in the samples isn’t exactly definitive proof of life yet, but it at least points to the possibility of an entire unknown biosphere deep underground:
This is another hint at a great, deep biosphere on our planet. It could be huge or very small, but there is definitely something going on that we don’t understand yet. I think of it kind of like a message in the bottle. We have this container coming up, and we are opening it up and trying to figure out what’s going on.
This discovery is not only exciting for geologists studying the Earth’s mantle, but also for astrobiologists searching for alien life - or searching for ways to conduct that search. Since conditions on most exoplanets are vastly different from our own and seemingly hostile to life as we know it, the presence of traces of life in these formidable depths shows that life, in the immortal words of Dr. Ian Malcolm, uh, finds a way. Hopefully, it has already found a way on other planets. Even if it hasn’t, however, discovering unknown lifeforms deep within the center of the Earth is pretty rad on its own.
While we’ve so far only been able to drill 12 kilometers (7 miles) or so into the Earth, the boundary between the crust and the next layer down, the mantle, lies close to 20 to 90 kilometers (12 to 55 miles) down. We’ve got a long way to go, but one Japanese scientific drilling ship, the Chikyū, has already launched an expedition to drill as far down as possible. Let’s hope the Balrog’s mood has improved.