Mars, nearly terraformed. According to Janus, the terraforming has employed self-replicating devices called "Dyson fans" in the outer solar system to bring in enough water to set up a dense atmosphere. The surface of the planet is still arid, due to the lack of permanent covering vegitation; in its place a grid of nanofactured soilstats keep it in place and manage the microstates. The current estimates suggest that it will be self-sustaining within a few decades. Note the many similarities with the terraforming of Adobe.

The picture is from the data collected in the 2338 joint Arcadia-New America expedition to the solar system. NASA press material.