MIMICKING MARS

A COMBINATION OF EXTREMITIES IN ETHIOPIA PRESENTS CONDITIONS MOST HOSTILE FOR LIFE THAN ANYWHERE ON EARTH. IT HAS TRIGGERED, YET AGAIN, A DEBATE OVER THE POSSIBILITY OF LIFE ON MARS

- SHREESHAN V DALLOL

ENTERING ETHIOPIA’S Dallol geothermal area in the Danakil Depression, one of the lowest land areas in the world, one might as well have stepped onto an easel. Bright yellow mounds streaked and speckled with hues of red and green create a dreamlike landscape. But numerous ponds stand unnaturally still here as they are fed by bubbling hot acid up to 108oC and brine that sputter out of the ground. A familiar stench of rotten eggs and rock salt overwhelms the olfactory nerves. The Danakil Depression, over the past year, has become a hotly contested stage in science’s quest to find the limits of life.

Situated in northern Ethiopia’s Afar region, the Danakil Depression is placed at the triple junction convergence of the Nubian, Somali and Arabian tectonic plates. The region is one of the few sites scientists can observe for the formation of a new ocean. It is replete with hydrothermal vents and volcanic craters of the Erta’Ale volcanic range. Increased volcanic activity some 30,000 years ago is believed to have created a ridge that cut off the depression from the Red Sea that previously occupied it. A coral graveyard and about a km-thick salt deposits that line the flat plains leading up to the Dallol geothermal area testify to the submerged part of the region.

The Dallol hydrothermal field, spread over just 1 sq km around the Dallol volcanic crater, has brine-spewing vents and cones of mineral deposits. The Dallol crater has high concentrations of chlorine, sodium, iron, potassium, sulphur, magnesium and calcium. Their highly saturated combinations lend to the incredible colour palette and mushroom-like salt deposits.