December 20, 2001. Copyright, 2001, Graphic News. All rights reserved

Depths of Lake Vostok may reveal Europa secrets
By Elisabeth Ribbans

LONDON, December 20, Graphic News:  A VAST and untouched lake that has been buried at the bottom of the world for 15 million years should be a scientific curiosity in itself.

But Lake Vostok, situated 1,600km from the South Pole, holds a special fascination for the clues it may contain to life far removed from our own planet. Sealed over by a roof of Antarctic ice measuring 4km thick, the lakeÕs dark and virtually atmosphere-free environment is believed to mirror that of Europa, the icy moon of Jupiter. 

Scientists speculate that, cut off from the rest of the Earth for so many millennia, unique microorganisms called extremophiles -- discovered in ice samples just above the surface of Lake Vostok -- may have evolved without the need for heat or light. If so, it will boost the hopes of astrobiologists who believe Europa might also be capable of supporting some form of life. Although the surface temperature of our solar systemÕs sixth largest moon languishes at -170C, heat generated by continual expansion and contraction of its crust Ð caused by the gravitational tug of Jupiter and the planetÕs other moons Ð may have melted part of the ice beneath the surface to create hidden lakes or oceans.

Possible evidence for this theory concerns the brown ridges that mark the moonÕs terrain, thought to be caused by instant freezing of liquid water erupting from beneath the ice crust. In March 2002, astrogeophysicist Brad Dalton will present a research paper to the Lunar and Planetary Science Conference, suggesting that EuropaÕs red glow is caused by frozen particles of bacteria, once again blasted up from subsurface waters.

But it will be several years before scientists can verify with certainty whether Europa does harbour liquid water. The Europa Orbiter, whose main goal is to verify its presence or absence, is not scheduled to begin surveying the Jovian moon until late 2011. In the meantime, the 10,000sq km Lake Vostok, which was first discovered in 1974, will provide a crucial test bed for rehearsing the mechanics of exploring extreme subterranean waters. Taking samples from the lake Ð or from any Europan ocean Ð without contaminating its pristine environment represents a huge technological challenge. Drilling that stopped short of the surface of Lake Vostok has already been carried out, providing scientists with valuable information about EarthÕs climate over the past 400,000 years. Now a program, involving NASA and other scientific institutes, is underway to develop two non-polluting companion robots Ð a ÒcryobotÓ to penetrate the ice and a ÒhydrobotÓ to delve into the waters. Comparable robots would be used on Europa if the orbiterÕs findings proved positive.

Whether or not there is life in Lake Vostok, the information it yields will help astroscientists determine further the spectrum of conditions for viability and thus guide them in their search for life throughout the solar system.
/ENDS

Sources: Jet Propulsion Laboratory, California Institute of Technology; NASA; Space Daily