The search for life in extreme environments is an exploration not only of the robustness of earthly life, but also of our origins. And perhaps the biggest question here is whether the earth is a unique jewel in an otherwise dead solar system.
Recently my colleagues and I investigated life in a unique ecosystem beneath a frozen lake system (Lake Vida) in the Antarctic dry valleys.
The project was lead by Peter Doran at the University of Illinois at Chicago and followed on from many years of research by Doran and other Antarctic researchers.
This week a paper by Alison Murray from the Desert Research Institute in Reno, Nevada and other collaborators – including Peter Doran – presented intriguing results from a new project that involved drilling into Lake Vida.
It is important to emphasise the extreme care that went into the drilling and sampling of the lake in order to prevent contamination of the samples and, in turn, the frozen ecosystem.
Imagine scenes of researchers working in freezing conditions garbed as if to perform open-heart surgery. A sterilised drill system was used to break through the frozen surface of the lake to the brine 20m below. The drilling took place within a clean tent system and was performed by researchers wearing clean room suits and sterilised equipment.
The study found microbial life in the dark brine system under the lake’s ice cap. This life is extremely small and spherical, typical of aquatic bacteria.
These organisms manage to exist despite extreme conditions including temperatures of -13ºC, extremely high concentrations of dissolved metals and salt, laughing gas (N2O) and hydrogen (H2).
A major question posed by the Murray and colleagues was: “what is the energy source powering this ecosystem?”. The question is important since the ecosystem is sealed up and in the dark. Without new energy coming in the ecosystem could not support life.
This fundamental question has implications not only for the search for life in other parts of the solar system but also on the early beginnings of life on Earth.
Clues from Lake Vida’s unusual brine chemistry – such as the presence of laughing gas and hydrogen – suggest the energy comes from chemical reactions between the brine and the underlying rocks.
Other than being powered by chemical reactions between salty water and rocks, another interesting feature of the life found below Lake Vida is that it appears to be living slowly. That is, the chemical machinery within the organisms is cranking slowly.
This is not surprising given the extremely low temperatures. Other studies have found that the extremely slow metabolism displayed by the microorganisms is a good survival mechanism for low temperatures.
If we extrapolate from this study it would seem that life really could exist in other icy parts of the solar system. But any life we do find is likely to be very slow, much like the life we’ve found under Lake Vida.
Ron Chinchen
Retired (ex Probation and Parole Officer)
I often feel so thankful to live in such an age, though I regret a little that I will not be here in several decades to see further revelations as they come to public awareness. So much of what we humans preconceived of the universe in which we live, is being challenged and overturned. What we thought intuitively based on the limits of our knowledge and experience is being shown to be not only insular, but in religion and philosophy it has created foundations of beliefs and thoughts that are in fact…
Read moreDianna Arthur
Dianna Arthur is a Friend of The Conversation.
Environmentalist
Given the (impossible to envision) size of the universe, the likelihood humans are the only intelligent life forms, let alone our planet Earth being the only planet capable of supporting life appears more and more improbable as we learn more and more.
Just hope I will be alive when (not if) we find life (no matter how small) elsewhere in our own solar system.
Chris Booker
Research scientist
Completely agree. The whole 'alien life' question, which I take literally to mean simply 'life elsewhere', has become so tied up with little green men, UFOs and hollywood science fiction that it's difficult to talk about it a serious manner But to me given we're on such a small planet in one little corner of the milky way, which in itself is only a fraction of the universe out there, saying life exists elsewhere seems like the most logical conclusion you could possibly arrive at.
Dianna Arthur
Dianna Arthur is a Friend of The Conversation.
Environmentalist
@ Chris Booker
I cannot believe that our little planet in a solar system on a far flung arm of the Milky Way galaxy among myriad other galaxies is the only repository for life.
If we human beings are all that there is, then I think that is quite sad. A planet full of smart apes, many of whom believe they can pollute, dig up and exploit everything this fragile ecosystem, Earth, has to offer, without consequences.
Les Tombs
logged in via Facebook
this story of life under the ice in extremely low tempuratures,must give heart to those people interested in space travel and suspended animation,,and the keeping of a loved one,,in a cryogenic state...----allowing medical science to prolong life in the future,,,,,,,what a universe we live in
Fred Moore
Builder
“what is the energy source powering this ecosystem?” It's the WRONG question.
The THERMODYNAMICS of life demand an entropy or HEAT gradient to allow electrons (or indeed other fundamental particles) to cascade down cistene chains to create the building blocks of life and life itself. The only limit to the life produced is the STRENGTH of the gradient.
Under L Vida there are two areas where heat gradients exist: 1. the lake bed or any geological feature which leaks tiny amounts of GEOTHERMAL…
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