Mars Q&A: Is now the time to explore the Red Planet?

Mars, our neighboring planet, has captured people's imaginations for centuries. In the last 50 years, orbiters and rovers have been exploring its environment, its atmosphere, and its geology, sending back a wealth of information. The more we learn about the Red Planet, the more we want to send human explorers there. Is now the time to go? The National Aeronautics and Space Administration's priority is Mars, but there are conflicting opinions among US decision makers about the country's space-travel priorities.