From: LARRY KLAES (ljk4_at_msn.com)
Date: Sun Jun 22 2003 - 09:52:35 PDT
What draws humans to the Red Planet after so many failures? It's simple -- life
--------------------
By James B. Garvin
Special to the Sentinel
June 22, 2003
Mars, the Red Planet, beckons us today as we commence the first overland exploration of another world, in search of clues to the origin of life.
Why this fascination with a planet seemingly so foreboding and hostile? What draws us to its beguiling surface again and again, despite dramatic setbacks?
Over the past several years, we have witnessed a scientific revolution in the making, one that links what we seek to know about Mars with a new awareness of the biological evolution of our own planet.
Thanks to the breathtaking reconnaissance of two spacecraft, the Mars Global Surveyor and Mars Odyssey, a new picture of Mars has recently emerged. It is one that offers remarkable prospects for having preserved records that could tell us how life came to be here on Earth.
By following the sometimes elusive clues to how liquid water has existed on Mars both now and in the long-distant past, scientists now believe there may have been life-friendly epochs on the Red Planet during which biology may have sprung forth, only to be later eradicated by the hostilities of changing Martian climates and environments. If the records of these past epochs can be found in the rocks on Mars, we may gain a tantalizing "window" on the earliest moments of life on another world and by analogy a glimpse as to what may have happened here on Earth.
We are truly in search of the greatest "scientific gold" we can imagine -- evidence of life elsewhere in the universe. If we were to find that Mars once harbored even the simplest forms of life, then the prospects for life elsewhere in the solar system and beyond would be magnified enormously. The challenge lies in learning to read the "record in the rocks" on another world whose evolution may not have exactly paralleled that of our own home planet. To some, this is the greatest forensic problem of the century, seeking the "stuff of life" tens of millions of miles away on a distant, bizarre planet. But the challenge remains -- how can we unearth (or un-Mars) the records of past climates and ultimately of ancient organisms on a world with a land-area equivalent to that of all the continents of planet Earth combined?
NASA's Mars Exploration Program has been crafted to seek answers to problems that have captivated people for centuries, including whether we are "alone" as living organisms in our neighborhood of the universe. In spite of the challenges of exploring an enigmatic world as far distant as Mars, NASA's Mars program is poised to make major headway over the next several years with an unprecedented campaign of scientific investigations, culminating someday in the knowledge and capabilities necessary to make the decision and commitment to send human explorers to the Red Planet.
Today's Mars Program is focused on learning how to efficiently explore the surface and accessible subsurface of a planet that presents an enormous "search space" to us. The overland roving explorers named Spirit and Opportunity launching this summer represent a huge leap forward. They offer us, for the first time, access to the materials on the Martian surface we must study and ultimately understand if we ever hope to directly search for the records of ancient or perhaps even modern life. In some ways, our current program of Mars exploration is akin to the popular TV show CSI in which forensic techniques are used to solve crimes, but in this case we are attempting to decipher Mother Nature's ancient mysteries written in stone and soil on Mars.
The prospects for learning whether Mars ever harbored life of any sort are better today than they have been in a generation, and NASA's present program of exploration will set the stage for unambiguously determining whether there were ever Martian life-forms over the course of the next 20 years or so.
As we send our intrepid Mars Exploration Rovers to Mars this year, we look ahead to extending the quest for life to global scales with our 2005 Mars Reconnaissance Orbiter. This orbiting spacecraft, capable of spotting objects the size of beach balls on the surface, will chart the martian landscape from above at human scales much like Captain Cook explored the southern oceans of Earth centuries ago. This mission will also explore the shallow subsurface of Mars in search of buried "reservoirs" of water and generate the first mineral maps of Martian carbon-bearing materials, if any exist.
It will be followed by a long-lived mobile laboratory that will build upon the discoveries to be made by our 2003 rovers and conduct CSI-like laboratory studies of materials that we expect to contain the stuff of life. By 2010 we will transition from our present focus on "following the water" to "following the Carbon" as we seek to understand how Mars may have preserved the records of ancient life -- the fossil record of another world.
What we learn from our missions over the next eight years will show us the pathways to explore in the coming decade, including the possibility of bringing a few priceless pounds of Mars rocks, soils and ices safely back to Earth for exhaustive and exquisite laboratory analysis. Another pathway could include a sophisticated, mobile biological laboratory on the Martian surface, conducting experiments better done on Mars than here on Earth, as we continue our quest for life.
All of these robotic voyages of discovery will lay the foundation of knowledge and experience necessary that decision-makers will need to decide when it is time to send human explorers to the Red Planet as the ultimate agents of discovery, adventure, exploration and inspiration.
Two hundred years ago, our fledgling nation chose to send Lewis and Clark and their Corps of Discovery on one of the greatest overland expeditions in history, and within a generation the discoveries they made reaped benefits for the entire country. Today, we send robotic explorers to the planet Mars as a bold step forward in our quest for understanding the prospects for life elsewhere in our solar system and to lay the groundwork for future human voyages to the Red Planet.
Perhaps author Daniel Boorstin unknowingly captured an aspect of our exploration of Mars in his book The Discoverers that bears repeating:
"The most promising words ever written on the maps of human knowledge are terra incognita -- unknown territory."
Mars is indeed a terra incognita that may tell us ultimately we are not alone, or, better still, that our origins are traceable to other worlds whose histories can tell us about parts of our long-lost past here on Earth.
Maybe our fascination with Mars goes far beyond science, extending to the passions of exploration that are part of our uniquely American experience. We go to Mars today to inspire future generations to take up the charge, so that they can uncover "scientific gold" and experience the universe in ways we cannot even imagine today.
We aren't sure what we will ultimately learn and discover, but the quest will teach us how to better understand ourselves and our place in the universe.
This archive was generated by hypermail 2.1.6 : Sun Jun 22 2003 - 10:11:28 PDT