In the eerie bluish-purple depths of an Antarctic lake, scientists have discovered otherworldly mounds that tell tales of the planet’s early days. Sumner and her colleagues, led by Dale Andersen of the SETI Institute in Mountain View, California, describe the discovery in an upcoming issue of Geobiology. "These are just incredibly beautiful microbial landscapes," she says. Researchers have probed many Antarctic lakes to study the weird and wonderful microbes that live there. Andersen alone has dived into at least eight such lakes. But he says the discovery of the stromatolites rocketed East Antarctica’s Lake Untersee "to the top of my list." Researchers study fossil stromatolites, from 3 billion years ago or more, to understand how life got a foothold on Earth. Today, stromatolites actively form in only a few spots in the ocean, like off the western coast of Australia and in the Bahamas. They also grow in some freshwater environments, like super-salty lakes high in the Andes and in a few of Antarctica’s other freshwater lakes. But scientists have never seen anything like the size and shape of Untersee’s stromatolites. Drawn by its extremely alkaline waters and high amounts of dissolved methane, Andersen and his colleagues traveled to Untersee in 2008 to drill through its permanent ice cover and collect water samples. Andersen was used to finding mats of bacterial growth in other Antarctic lakes, but nothing like the big mounds he saw when he dived under the ice at Untersee. Up to half-a-meter high, these purplish piles studded the lake’s bottom like barnacles clinging to a ship hull. "It totally blew us away," Andersen says. "We had never seen anything like that." Samples of one of the mounds showed that it was made mostly of long, stringy cyanobacteria, ancient photosynthetic organisms. The bacteria may take decades to build each layer in Untersee’s frigid waters, Sumner says, so the mounds may have taken thousands of years to accumulate. Oddly, the stromatolite mounds sat next to smaller, pinnacle-shaped lumps that researchers had seen in many other lakes. And the stromatolites were made mostly of Phormidium bacteria, while the pinnacles were made of another group, Leptolyngbya. To Sumner, that sharp distinction between bacterial composition on different-shaped lumps says something significant about Untersee. "Everywhere else that we’ve looked you have a gradation between the structures," like in bacterial mats sprawling around Yellowstone’s hot springs, she says. "There’s something very special about this particular example that’s allowing these large conical stromatolites to form." But scientists aren’t sure yet what that something special is. Andersen’s team has recently studied two other ice-covered Antarctic lakes, Vanda and Joyce, without finding large conical stromatolites there. Conditions vary from lake to lake, making each of them unique in its own frigid way. Lake Vanda, for instance, has a more transparent ice cover that lets more light penetrate. Lake Joyce has thicker ice, which constrains how far down photosynthesizing organisms can grow. Understanding what makes Untersee different would help scientists better figure out the limits on life, both today and in the long-distant past. "It’s a real challenge to our understanding of how these communities developed," says Ian Hawes, a polar limnologist at the University of Canterbury in Christchurch, New Zealand. More answers should come this November, when Andersen’s team is scheduled to return to Untersee to scrape up more samples of the ghostly blue mounds. Image: Eerie blue light suffuses the otherworldly bottom of Lake Untersee, Antarctica, where scientists have found structures (purple lumps) built by layer upon layer of growing microbes. (Dale Andersen) It is the essential source of information and ideas that make sense of a world in constant transformation The WIRED conversation illuminates how technology is changing every aspect of our lives—from culture to business The breakthroughs and innovations that we uncover lead to new ways of thinking This website is using a security service to protect itself from online attacks The action you just performed triggered the security solution There are several actions that could trigger this block including submitting a certain word or phrase You can email the site owner to let them know you were blocked Please include what you were doing when this page came up and the Cloudflare Ray ID found at the bottom of this page WHERE TO MEET On the occasion of the Swedish national holiday on Sunday a unique exhibition of 30 Saab and Volvo classic cars each will take place in the historic Stedtli of Unterseen under the motto "Heja Sverige" The classic cars represent Swedish cultural heritage and car building art from the era 1950 to 2000 Special highlights of the presentation are various Saab 93 [...] The classics represent Swedish cultural heritage and car building art of the era from 1950 to 2000 Special highlights of the presentation are various Saab 93 - 96 as well as the lightweight Saab sports cars Sonett (gallery below) which drove from Hamburg to Hong Kong and a P1800 which took the route from Gstaad via Berlin to Beijing without any problems stand for the history of Volvo (gallery above) Presentations of legendary historical models In addition various historic sports and rally models of both brands enrich the unique presentation The exhibition in the middle of the old town of Unterseen is open to the public and free of admission For the culinary well-being on site with some Swedish delicacies provides the well-known restaurant Stadthaus For more information c.bleile@bluewin.ch monil shah has posted 10 comments on Timesofindia.com to earn the Wordsmith Level 1 badge You have been successfully added to the mailing list of TimesTravel kindly open your inbox and click on the confirmation link which has been emailed to you Thank You for sharing!Your friend will receive the point of interest link on email mentioned One of the more modern restaurants in the historical town of Unterseen a few minutes away from the centre of Interlaken Benacus serves global cuisine with a twist using the freshest produce in the r...