What Is Life?

The two NASA robots continue to poke around on the surface of Mars. We are explorers – even robotically. The difference between these explorers and a Columbus type explorer is what they’re looking for.

Back in the 15th Century, man was looking for a shortcut to goods he could use. If the trips were successful, spices, gold and other treasures would come back on a triumphant return. At the moment, nothing’s coming back from Mars.

Today’s explorers have a somewhat more ethereal goal. We’re looking for signs of life, the origins of life, the origins of our universe. It’s heady stuff. It’s exploration in the abstract. Unlike the 15th Century, there may be no practical payoff.

Today the AP reported; “Mars rover Opportunity has found evidence that the Red Planet was once wet enough for life to exist there, but the robot has not found any direct traces of living organisms, NASA scientists announced Tuesday.

Of course, the next step will be to look for signs of life. But (with apologies to George Harrison) what is life? It’s not a stupid question. If you’re thinking people, insects, plants, you’re way up the ladder from where scientists will look. In fact they will be looking for incredibly simple forms of life – forms so simple, that to me, it’s difficult to separate life from simple chemistry.

A few years ago I went to NASA’s Johnson Space Center in Houston to look at ALH84001, the Allen Hills meteorite. Some scientists believe this chunk of Mars, which through an unbelievable confluence of events ended up on Earth, holds fossilized evidence of Martian life. But the fossils are so simple, the life so rudimentary, that most lay people would yawn and turn away. That’s how I feel about its fossils – though the story of how it got to Earth and how why scientists know to go to Antarctica to find meteorites is more than a little fascinating.

Over the next few months, NASA will probably use the results of this incredible engineering triumph to try and fund more missions, and people will start talking about searching for life. Just remember, it might not mean what you first thought.

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