Curiousity...

NASA Mars Science Laboratory

Today (25 July 2012), the Mars Science Laboratory's terminal descent sensor is being checked out in preparation for Curiosity’s entry, descent and landing. The sensor is a radar system that is mounted on MSL's descent stage. Following separation of MSL's heat shield at an altitude of approximately 5 miles (8 kilometers) and a velocity of approximately 280 mph (125 meters per second), the sensor begins collecting data on the spacecraft's velocity and altitude in preparation for landing.

Sometimes, I think we forget we're still exploring deep space, with the eventual goal of manned missions to at least Mars for starters.

Some proposed ideas I've heard in the past: terraforming the Martian atmosphere with - smog, of all things - to warm it up a bit for human habitation, an ironic positive effect of warming a planet, i.e. if we can control it.

For more on the countdown:

NASA - Mars Science Laboratory