Thursday, June 23, 2011

'Mars in a Bottle' Tortures Bacteria

It's hard to believe that nearly 35 years ago we conducted the first -- and so far last -- experiments to find life on Mars.

In 1976, two NASA Viking landers scooped up some orange Martian soil and attempted to incubate any native microorganisms that might be present. The results were ambiguous as best, and have been hotly debated ever since.

The Viking experiments were criticized as being too premature because in the 1970s we didn't know very much about the Martian environment or its geological history. In fact, the Viking experiments may have actually killed exotic native life say some astrobiologists (Viking's view of Mars is pictured below). We didn’t even know about the existence of extremophiles on Earth back then -- tough microbes that adapt to hostile conditions that would normally kill us.

Before we send another biology experiment to Mars, says a team of researchers at the University of Padova, Italy, let's build our own Martian environment in a lab and see what Earth life forms might survive. Call it a "goldfish bowl" for seeing if life can live on the edge.

Finding a life form able to survive in homemade Martian conditions may have a double payoff says the team, lead by Giuseppe Galletta. It might expand our understanding of the limits of environments where life can survive.

The experiments would also define the limits for how easy or hard it would be to accidentally contaminate Mars with Earth bugs.

The small Martian environment simulators they built (pictured top), called LISA and mini-LISA (Laboratorio Italiano Simulazione Ambienti), make an attempt at duplicating Martian surface conditions.

Inside the mini-Mars habitats, temperature ranges from a maximum of near-freezing in the tropical Martian summer to –200 degrees Fahrenheit (-130°C) in the harsh polar winter. Air pressure is kept at an anemic fraction of a percent of Earth's surface pressure. The bottled atmosphere is 95 percent carbon dioxide with trace elements. Searing ultraviolet (UV) light floods the habitat.

What's handy is there are no time limits on the experiments. The mini-Mars world is refueled with liquid nitrogen weekly to keep it chilly.

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