There is no doubt that Mars remains a hugely important target in astrobiology, planetary science, and even human exploration. Between our increasingly good understanding of Martian water distribution (from polar regions to lower latitudes), and the extraordinary observations of a summer plume of some 19,000 metric tons of methane, it is a planet full of tantalizing clues.
The right strategy for exploring Mars is tricky, it has to balance scientific goals, technical feasibility, the potentially delicate nature of the Martian system - possibly even its ecosystem - and budgets. I was incredibly fortunate yesterday to have the opportunity to join a conversation with Buzz Aldrin. He brought up the idea that the Martian moon Phobos represents a perfect 'base' for exploration of all kinds. The more I think about it, the better an idea it seems. He made the point that human control over surface rovers is horribly inefficient when the human is sitting on Earth sipping tea. It takes between 10 and 20 minutes for light to travel from the Earth to Mars and back again, depending on where the planets are in their orbits. Controlling a rover on Mars becomes a matter of sending complex 'instructions for the day' and having the rover cautiously inch its way around.
So, perhaps the best way to explore Mars is to go to Phobos.