Has the century-old mystery of Antarctica’s “Blood Falls” finally been solved?

In 1911, an Australian geologist named Thomas Griffith Taylor was exploring a valley in Antarctica when he stumbled upon a wierd waterfall. The meltwater flowing from beneath the glacier that now bears Taylor’s identify turns a deep purple upon coming into contact with the air, incomes the website the moniker “Blood Falls.” Various hypotheses have been proposed over the final century to clarify the unusual phenomenon. A group of scientists now thinks they’ve finally discovered the reply: tiny nanospheres wealthy in iron, silica, calcium, aluminum, and sodium, amongst different components.

But why has fixing this mystery taken greater than a century? It appears the nanospheres are amorphous supplies, that means they lack a crystalline construction and therefore eluded prior analytical strategies in search of minerals as a result of they don’t seem to be, technically, minerals, in line with a current paper revealed in the journal Frontiers in Astronomy and Space Science. That may seem to be an odd alternative of journal for this examine, however the Blood Falls at Taylor Glacier is a so-called “analogue” website for astrobiologists and planetary scientists eager to be taught extra about how life may evolve and thrive in comparable inhospitable environments elsewhere in the universe.

“With the creation of the Mars Rover missions, there was an curiosity in attempting to investigate the solids that got here out of the waters of Blood Falls as if it was a Martian touchdown website,” mentioned co-author Ken Livi of Johns Hopkins University. “What would occur if a Mars Rover landed in Antarctica? Would it be capable of decide what was the reason for the Blood Falls to be purple? It’s an enchanting query and one which a number of researchers had been contemplating.”

Those researchers embrace his co-author, Jill Mikucki of the University of Tennessee, a microbiologist who has been learning the Taylor Glacier and its distinctive waterfall for years. She and her group beforehand studied samples taken from the website utilizing a set of methods additionally utilized by NASA for its Mars missions to discover that planet’s floor. Those embrace Mossbauer spectroscopy utilized by Spirit and Opportunity; seen to near-infrared spectroscopy (VNIR); mid-far infrared spectroscopy used on the Mars Global Surveyor and Mars Odyssey; in situ x-ray diffraction (XRD) utilized by Curiosity; and Raman spectroscopy used on Perseverance.

In 2009, Mikucki’s group detected residing organisms—17 differing types of microbes—in the lake beneath the glacier, possible in a position to survive the darkish, oxygen-free waters by drawing vitality from sulfur and iron. In 2014, the group used a particular probe referred to as IceMole to instantly pattern the salty water flowing into the Blood Falls. Mikuchi’s group mapped all the glaciers, caves, and rivers to find out that the water originates from a briny subglacial reservoir wealthy in minerals, which accrued in the ice because it moved throughout the rocks. And they discovered that the brine was very chilly ( minus 7° Celsius, 19° F), wealthy in iron, with 8 p.c sodium chloride. Plus, they had been in a position to isolate a salt-water-loving micro organism that thrives in the chilly, anaerobic surroundings, in addition to two different sorts of micro organism.