Very critically, how do we protect it, if we find it, and not contaminate it?

And then, secondly, getting back to that earlier point that I made about the preciousness of any life that we may find on Mars, we don't want to contaminate it.

And also, as an increase in extreme weather events due to climate change, they're expecting more waves to come in over the fringing reef, which will contaminate their fresh water supply.

And we didn't want to take it propulsively all the way to the surface because we didn't want to contaminate the surface we wanted the Rover to immediately land on its legs.

Fourth, pollen from GM crops may contaminate organically produced food. This, of course, would be an issue only with open pollinating plants, and only if the definition of organically produced excludes GM, something that is difficult to justify, since genes are as organic as anything.

How can we undo the imbalances of economies China, followed far behind by Europe exporting massively to the United States or to the dollar zone? Will the US mortgage market, which is expected to become even more difficult in 2008, subside into calm afterwards, or will it contaminate the whole international financial system?

CAMBRIDGE Fear of a cyber Pearl Harbor first appeared in the 1990s, and for the past two decades, policymakers have worried that hackers could blow up oil pipelines, contaminate the water supply, open floodgates and send airplanes on collision courses by hacking air traffic control systems. In 2012, then US Secretary of Defense Leon Panetta warned that hackers could shut down the power grid across large parts of the country.