February 21, 2024

Bright red waterfalls don’t come across in the ice of Antarctica, but that’s exactly what falls from the foot of Taylor Glacier. A team of scientists now claims to have solved the long-standing mystery behind the crimson waters of Antarctica’s Blood Falls.

First discovered in 1911, geologist Thomas Griffith Taylor attributed this eerie and eerie sight to red algae. It wasn’t until half a century later that it was determined that the deep red color was caused by iron salts. Most intriguingly, the water was clear at first but turned red shortly after emerging from the ice as iron oxidized when it was exposed to air for the first time in thousands of years.

Now, a new study examines water samples and finds iron in an unexpected form. It’s not technically a mineral, but in the form of nanospheres, 100 times smaller than a human red blood cell.

“When I looked at the microscope images, I noticed that there were these little nanospheres, and they were rich in iron, and besides iron, they contained many different elements — silicon, calcium, aluminum, sodium — and they were all vary,” said study author Ken Levy. “In order to be a mineral, the atoms must be arranged in a very specific crystalline structure. These nanospheres are not crystalline, so methods previously used to examine solids cannot detect them.”

The discovery has implications beyond Antarctica and beyond Earth. Just a few years ago, scientists managed to trace the water back to its source—an extremely salty subglacial lake under high pressure, without light or oxygen, and a microbial ecosystem that had been isolated for millions of years. Life may exist on other planets under similarly harsh conditions, but we probably won’t send the right equipment to find it.

“Our work shows that analyzes performed by rovers are incomplete in determining the true nature of environmental materials on planetary surfaces,” Levy said. “This is especially true for cooler planets like Mars, where the materials that form can be nanoscale and amorphous. Therefore, our methods of identifying these materials are insufficient. To truly understand the properties of rocky planetary surfaces, we need A transmission electron microscope, but putting one on Mars is not currently feasible.”

The study was published in the journal Frontiers in Astronomy and Space Science.

source: Johns Hopkins University