Exploration of Mars can reveal key secrets about where life began

As President Bush outlines plans for putting humans on the face of the cursed red planet, we have to ask ourselves, what is the big deal about Mars? A trip to Mars would be hugely expensive when completed in 20 to 25 years. Who cares?
Mars research has been a difficult process. Whole careers have been derailed. Ptolemy, who devised an early earth-centered view of the solar system, failed to explain why Mars seemed to back up in its orbit occasionally.