Tuesday, December 24, 2013

A lake where scientists study ‘alien’ life

Tufa on Mono Lake, Calif.
Photo courtesy California Dept. of  Parks and Recreation
Day hikers can explore a region on Earth that scientists study as a possible analog to alien worlds on the South Tufa Trail at California’s Mono Lake Tufa State Reserve.

The self-guided trail runs about 2 miles round trip with ranger-led tours are available from May-October. For most travelers coming out of the green, mountainous Yosemite National Park to the west, Mono Lake offers a surprise in contrasts. At the nature reserve, hot air visibly flutters over the beige sands with white tufa columns rising from the lake.

Arsenic-based life
To reach Mono Lake from Yosemite, take Calif. Hwy. 120 east out of the Sierra onto the desert floor. The road briefly joins then splits from U.S. Hwy. 395. Turn left/north onto Test Station Road, following it an asphalt parking lot. An entrance fee is required. The trailhead is on the lot’s northern side.

The trail crosses Mono Lake’s desert beach then circles along its tufa-lined shore. Prior to World War II, before lake levels dropped, the bizarrely-shaped tufa formations here were largely hidden. Tufa forms when chemical released from underwater springs react with chemicals in the water, forming these limestone towers.

Those spires and the ancient volcano cones surrounding the lake make the scene otherworldy enough. But this hypersaline lake also has been the sight of astrobiological research – or the study of extraterrestrial life. A scientists during the early 2010s claimed she’d discovered a bacteria here that utilizes arsenic rather than phosphorous in its DNA, previously thought impossible and widening the number of potential worlds where aliens might exist. Research since has disputed the finding, but the claim helped expand our thinking about how life might be shaped across the cosmos.

Birder's paradise
Even if such a radical lifeform doesn’t exist in Mono Lake, quite common creatures on Earth certainly like the waterbody. About 9 in 10 of California’s gull population was born on the lake. In one count, an estimated 800,000 eared grebes inhabited the lake. The migrating red-necked phalaropes, which winters in South America, also have been spotted here. Among the birds’ favorite food is brine shrimp, which adapted during the past million years to the lake’s high salinity.

Since the mid-1990s, efforts have been undertaken to raise the lake’s levels, which had dropped 40 feet since 1941 when streams and rivers that fed it were diverted to supply Los Angeles with water.

Because of that, in years ahead the trail you hike now likely will be changed as rising lake levels reclaim the shoreline.

Find out about trail guidebooks available in the Hittin’ the Trail series.