Ceilidh

Michael Zey
futurist3000@aol.com

Behold the Spirit rover, stretching its solar wings to charge its batteries, checking its Instruments, photo­graphing its surroundings, getting ready to roil. Spirit should move across the floor of the Gusev Crater at a clip of 100 feet a day, examining scattered rocks and sediments in what seems to be the basin of a dried-up
ancient lake bed. It will record these fea­tures with cameras and a microscope and analyze their chemical composition with spectrometers.

As it moves and explores, millions of Americans will continue to be mesmerized. According to NASA, in the 48 hours after Spirit landed on Mars, lti Web site re­ceived 513 million hits. With luck, Spirit and its sister vehicle, Opportunty, which Is set to arrive on the Red Planet on Jan. 24~, could go on roving for a couple of months.

It’s been three decades since the idea of a mobile robotic Mars rover was seriously proposed, and now, finally, we have one. As a longtime advocate of liumnan Mars explo­ration, I can only watch this mission with delight. And nothing pleases me more than the news that President Bush Is expected today to announce plans for the human ex­ploration of Mars. Sending huina~is there is essential because, as wonderful as they are, neither Spirit nor Opportunity nor any other machine will ever tell us what we need to learn about Mars.

Because Mars almost certainly once had flowing liquid water, it is the Rosetta stone that holds answers to questions about the origins of life. If we can find fos­sils of indigenous life on the Martian sur­face, we will know that life is a general phe­nomenon in the universe. If we can drill down a kilometer or so and find extant life forms, culture them and examine their bio­chemistry, we will get our first glimpse as to what the diversity of life might really be. And yet fossil hunting — on Earth, at leastinvolves traveling many miles through unimproved terrain, climbing up steep hill­sides, doing heavy work like digging and using a pickax, doing delicate work like careftilly peeling sedimentary rocks apart edgewise to see what Is trapped between the layers and using Intuition to follow up subtle environmental clues to make key discoveries.

Presumably the same skills would be required on Mars, and yet these tasks are all far beyond the ability of robotic rovers. During its lifetime, Spirit’s 100-feet-a-day rolling speed will allow It to travel about a mile. A human explorer operating on foot could traverse that distance in half an hour or In three minutes driving a Mars bug~,.

Spirit will probably be able to de­termine if Gusev Crater was indeed once an ancient lake bed. But it can’t do any se­rious digging, so it won’t be able to reach the lake sediments several yards under­ground that might contain evidence of past life and organic material Imagine traveling 250 million miles to reach Mars but having to stop a few yards short of where the important discoveries caine made. That Is the limitation faced ~,y Spirit.

But let us presume that despite the
odds, the slow-moving Mars rovers have the enormous luck to image some feature on a rock that has the appearance of a fo& sil microbial community. As exciting as that might be, it would still fall to address the key question.

Mars and Earth are not biologically isolated. As a result of asteroidal Impacts that periodically splatter material from each planet off into space, there Is a natural
transfer between worlds. Three and a half billIon years ago, it seems clear that there was water on Mars and that Earth was al­ready covered with bacteria So there al­most certainly was life on Mars at that time, if from no other source than Earth. The real question is not whether there wa ever life on Mars but whether guch life hac a separate origin or a comnxm butprlor origin from Earth life. Were there two ~enesesin our solar system or just one? It two, did both types employ the same bio­chemical plan? If one, was it life from Emil that seeded Mars, or did Mars seed the Earth?

To find out, NASA must look not just be left to robots
for fosslls but for extant life. Spirit and Opportunity have no life detection instru­ments. Beagle 2, the British lander that was expected to reach Mars on Christmas Day and hasn’t been heard frOm, did have suchinstruriienta, as did the two Viking spacecraft that landed on Mars in 1976.

The Vikings conducted four life detection experiments each, which gave a mix of contradictory data leading to no definite conclusion.

Beagle 2 seems to have felled in its landing, but if it had succeeded, it could have searched for methanogenic bacteria by sniffing with a methane detec­tor. Assume Beagle had sniffed  methane. What then? Was it emitted by native Martian organisms, by microbial liii- migrants from Earth or by subsurface geo­logic processes? By using robots only, there would be no way to know.

It is extremely unlikely that there is life on the Martian surface.

The place to look for life is underground, in liquid aquifers.
So the real requirement for Mars explora­tion is to set up rigs In various places that can drill down a kilometer to sample the. water table and, not only that, but to cul­ture and analyze the life forms found there. This Ii ajob for humans.

There Is an even greater question, how­ever, that can be answered only by human explorers on Mars, one bearing not on life’s past or present but on its future. That question is this: Can life born on one planet make a home for Itself on another?

     Do we have what It takes to settle Mars? There Is only one way to find out.

In the aftermath of the Columbia disas­ter, the investigatory committee headed by
Harold Gehman issued a strongly
worded report. It mostly specified correc­tive measures for mistakes that were made that caused the accident, but the final sec­tion made a larger demand on the space agency. NASA. the committee said, needs to decide what the purpose of its manned spacefllght program is. “We need to decide as a nation what it is we want todo,”he said.

The point is well taken. NASA’S budget today is, in inflation-adjusted lollars, 90 percent of its average Apollo-em levels. Yet our manned spaceflight program has been rudderless, and until now anyway, it has had no goal. Bush’s announcement could well change that.

If we are going to take the risks associ­ated with human spacefllght, we must un­dertake goals that are worthy of those risks. Flying astronauts around in Earth orbit to conduct paint-mixing experiments in zero gravity; as the Columbia crew was asked to do, does not qua1ify.

The Bush administration has taken the Gehrnan report to heart.

The spunky Spirit rover, as limited as it is, is participating In the real job of space exploration; it is going to the new world and seeking to help answer the greatest scientific and philosophical questions of our age. it is for that reason that the little machine is now the toast of the world. But whatever the rover can do, human explor­ers can do far better.We need to follow the Spirit to Mars.

Robert Zubrtn is president of the Mars So­cietV (www.marssociety.org) and author of “The Case for Mars” (Simon di Schusster) and
“Mars on Earth” (Tarcher Penguin).