Why should humans explore Mars?
One reason to explore Mars is scientific. We can increase the store of human knowledge through the exploration of Mars. Consider, for example, one very important scientific question: How did life originate on Earth? In order to shed more light on this question, scientists can ask a related question: What is the probability of life originating in a particular planetary environment? Exploring Mars will provide much data that may eventually allow scientists to reasonably estimate this probability. Granted that there are valid scientific reasons for exploring Mars, the next question is: Why use humans? Why not rely on robots, which are much cheaper and safer? The answer is that robots have limits. Consider, for example, the task of searching for Martian fossils that may be four billion years old. The oldest fossils on Earth have been found by paleontologists in remote corners of the globe, after years of pain-staking effort. Had this task been left up to robots, it is unlikely that these f
