Last August, the fourth in a series of NASA Mars roving vehicles set down inside a large crater on Mars. As the dust cleared, images began to arrive by radio, and the people of Earth beheld the wind-swept surface of another world so distant that radio signals from it required more than eleven minutes to reach home. One such picture was a self-portrait of the SUV-sized, extremely sophisticated machine “Curiosity,” while in the background an ominous mountain of sedimentary rock layers, over 18,000 feet high, rose against the bright Martian sky. I was once again reminded of words from “The Explorer” by Rudyard Kipling:
“Something hidden. Go and find it. Go and look behind the Ranges – Something lost behind the Ranges. Lost and waiting for you. Go!”
We are living in a remarkable time in history – when the accumulated knowledge of the entire human race can be accessed with the touch of a button on a mobile phone or computer. Furthermore, because of NASA’s commitment to openness, we are able to observe, at our leisure, the surfaces of alien worlds such as Mars within seconds of when NASA receives the images from deep space, at the same time as the scientists and engineers who have dedicated their entire careers to space exploration are seeing them. This, to me, is marvelous. But I do not have to look far on the internet to find the critics of space exploration voicing their opinions. One sarcastic comment I just encountered reads, “We could use all the money wasted on this space exploration to pay people not to work.”
Sarcasm aside, this is a good question: Why should we spend precious tax dollars to fund space exploration? One of the foremost reasons is very practical. If we want to understand and preserve our precious Earth, it is important to study the planets in Earth’s family – just as we might learn much about ourselves as individuals from the DNA of those humans in our own immediate family.
Scientists now call our time the Anthropocene – a period in Earth’s history when humans have become a dominant factor in the rapid deterioration of the atmosphere, the oceans, the land, and our precious biodiversity. As with all problems of a scientific nature, we need a laboratory in which we can observe and hence come to understand the effects of various factors that threaten our planet. Fortunately, we have just such a laboratory in our cosmic backyard! For instance, the surface of Mars is an exemplar of what the Earth’s surface would be like without a protective ozone layer. Continuously sterilized by ultraviolet light, it is extremely hostile to life as we know it.
We have come perilously close to losing our own ozone layer in the past few decades, but the international community has banded together in a rare display of unity, bringing that impending environmental disaster nearly under control by limiting the use of chlorofluorocarbons. Venus, our other nearest neighbor, has a surface temperature so high that it would melt lead – a consequence of an atmosphere made almost entirely of carbon dioxide, the primary molecule responsible for anthropogenic global warming.
Studying the causes and consequences of such forces of nature on other worlds is critical to understanding our own. In all scientific studies, we learn how processes operate by changing the variables. Can we predict how volcanoes and earthquake faults would behave on a world made largely out of ice instead of rock? We need only look to moons of Jupiter and Saturn to test our knowledge. This exploration falls under the term comparative planetology, the process of studying other worlds to help us understand our Earth. But comparative planetology is not, to me, the greatest reason to explore the solar system. We need to explore it because it is there! It nourishes the human need to explore, to wonder, and to stand amazed at God’s creation.
America was founded by people keen on exploring the unknown. We are a unique nation of adventurers and our program of space exploration has, until recently, had no rivals. I believe it is no coincidence that the people who worked the hardest to explore the New World have also worked the hardest to go beyond it. And now the history of Mars lies literally on the horizon—a history that may tell of the most incredible event to unfold in this amazing universe —the arrival of life. So, as the robotic explorer aptly named Curiosity treads like a heavy-laden hiker toward the distant flanks of Mount Sharp, carrying 17 cameras, a rock-pulverizing laser, and a list of other state-of-the-art scientific instruments as long as its own robot arm, I hope we will all take a few minutes every now and then to log on to http://mars.jpl.nasa.gov/msl/ and indulge the childlike wonder in all of us. It may also please you to know that the whole Mars Laboratory program has cost each U.S. taxpayer about $7.