Hidden lake discovery sheds light on alien hunt

July 7, 2017 by Anna Turns, From Horizon Magazine, Horizon: The EU Research & Innovation Magazine
NASA’s Cassini spacecraft has detected the building blocks of life in geysers hundreds of kilometres above one of Saturn’s icy moons, Enceladus. Credit: NASA/JPL-Caltech

Evidence of new strains of bacteria in a lake hidden under an Icelandic glacier far from the sun has revealed how life might thrive in sub-surface oceans on the icy moons around Saturn and Jupiter.

"Our preliminary results reveal new branches of life here," said Dr Gregory Farrant from Matís, a governmental research institute based in Iceland.

The lake – called Skaftárkatlar – is one of the best places on earth to study how life might evolve in the isolation of a subterranean on a far away moon, as it lies beneath an ice sheet 300 metres thick and its waters have probably never been exposed to the atmosphere.

"It's tricky to analyse DNA of microbes that are totally new to science because there's no prior knowledge about them," explained Dr Farrant, who is the lead investigator on an EU-funded research project called AstroLakes. "We're dealing with a lot of unknowns."

The team is studying microorganisms found in 10 precious samples taken from the lake over the last decade. Sampling beneath the glacier is difficult – a pump pulses hot water down to melt the ice in a column and then a sampler is sent to the bottom, collecting small volumes of sulphur-rich water.

The work is predicated on the idea that underground oceans probably represent our best chance of finding life on other planets.

Water-rich jets

NASA's Cassini spacecraft has already detected – the building blocks of life – by flying through geysers spouting hundreds of kilometres above the surface of Enceladus, one of Saturn's .

"By flying through the water-rich jets, the Cassini spacecraft has detected complex organic molecules as well as hydrogen, making Enceladus one of the most potentially habitable environments in this solar system," said Dr Gabriel Tobie, a planetary scientist from France's National Center for Scientific Research at the University of Nantes.

Using mathematical modelling, Dr Tobie and his team have mapped the thickness of the ice shell on Enceladus as part of the EU-funded Exowater project.

What they have discovered is while Enceladus' hidden ocean lies up to 35 to 40 kilometres beneath the icy surface at the equators, it could be less than 5 kilometres underground at the poles, a distance comparable to the ice caps on earth.

That's much thinner than originally believed, and makes the subsurface ocean potentially accessible during . It also suggests there may be hydrothermal vents on the ocean floor.

"This thinner crust implies that there is a huge heat source at this moon's interior which may power hydrothermal vents on the floor of this underground ocean," said Dr Tobie.

On earth, life spawns around ocean floor vents, despite the lack of oxygen and searing temperatures, raising the possibility that the same might happen elsewhere in the solar system.

Other moons, like Saturn's biggest moon, Titan, or Jupiter's moon, Europa, may also harbour these building blocks of life, and these research projects contribute more base reference points for future space missions to find out.

At the moment, NASA is considering a trip back to Enceladus in a proposed mission called Enceladus Life Finder, and to Europa in its Europa Clipper mission.

Iceland's Dr Farrant said: "Similar types of metabolisms are expected to occur in both places. Europa presents the conditions for to emerge."

Explore further: Image: Enceladus and its paper-thin crust

Related Stories

Image: Enceladus and its paper-thin crust

July 6, 2016

Of all the icy moons in the Solar System, Saturn's moon Enceladus is probably the 'hottest' when measured for its potential to host life. Despite its distance from Earth, it may also be the easiest to investigate.

All that life needs on Enceladus

April 17, 2017

If chemical energy is life's coin and water is life's marketplace, there may be a swift economy alive and well beneath the icy shell of Saturn's brightest moon. Such was the announcement during NASA's April 13th press conference: ...

Image: Potentially hospitable Enceladus

February 7, 2017

Seen from outside, Enceladus appears to be like most of its sibling moons: cold, icy and inhospitable. But under that forbidding exterior may exist the very conditions needed for life.

Recommended for you

Two sub-Jovian exoplanets orbiting bright stars discovered

March 19, 2018

Using NASA's prolonged Kepler mission, known as K2, astronomers have identified two new gas giant exoplanets. The newly found alien worlds, designated HD 89345 b and HD 286123 b, are warm, low-density sub-Jovian planets circling ...

Measuring white dwarf masses with gravitational lensing

March 19, 2018

Measuring the mass of a celestial body is one of the most challenging tasks in observational astronomy. The most successful method uses binary systems because the orbital parameters of the system depend on the two masses. ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.