Have you heard of microscopic animals called water bears? When I learned about these little guys a few years ago, my idea of what life is capable of was turned upside down and inside out. Also called tardigrades, water bears can survive extreme temperatures, pressure, radiation and even the vacuum of space! I’m fascinated by extremophiles— microorganisms that can withstand unimaginably harsh conditions—and what their existence could mean when we consider just how adaptive life can become.
Well, scientists have found yet more mysterious and fascinating extremophiles trapped inside enormous crystals. In Chihuahua, Mexico, there is a massive cave system connected to the Naica Mine called the Cave of Crystals. Named for its breathtaking selenite crystals (some have grown up to 30 feet long!), the cave was discovered by miners in 2000 and sits above a repository of magma. It’s exceedingly hot: it can reach up to 112 degrees Fahrenheit with intense humidity. In 2008, Penelope Boston from NASA and her team collected samples from fluids trapped in pockets within the giant crystals, and in February 2017 she announced their discovery of new microbial specimens—nearly 100 new extremophiles, most of which have likely never been studied by scientists before.
The creatures were found in a state of geolatency, trapped dormant inside geological materials (in this case, inside the crystals). Boston’s team was able to revive a number of the microbes, and they believe they could be anywhere from 10 thousandto 50 thousand years old! Scientists hypothesize that they survived by consuming iron, sulfur and other traditionally inorganic material inside the crystals, demonstrating that life may be more resilient and flexible than we previously thought. Some even think the existence of extremophiles makes it more likely that life could exist on other planets.
Other researchers are skeptical about Boston’s conclusions, specifically those concerning exactly how old the microbes are and whether possible contamination might have skewed the team’s results. Boston’s findings have not been peer-reviewed, and some scientists speculate that it may not be true that the microscopic organisms came solely from inside the crystal, as it may be possible some were accidentally introduced during the extrication process.
Another expedition into the Cave of Crystals might provide more answers, but the mine has since closed and the cave is now flooded with groundwater. Hopefully, a second look at these new extremophiles might further illuminate life’s limitations . . . if there are any.
Did You Know?
The very center of Earth may actually be made up of a massive conglomerate of crystals! Scientists used data collected from seismic waves to determine that Earth’s inner core—a solid region the size of the moon—may consist of two huge chunks of iron crystals, each aligned in a different direction (some north to south and others east to west).
Image Credit: Alexander Van Driessche