Although Atmospheric Incubator is a hypothetical megastructure, it's not as big as a Dyson sphere.
Links:
- 3DSMax2012 - Particles - Deflectors
- NASA Mission Reveals Speed of Solar Wind Stripping Martian Atmosphere NASA's Mars Atmosphere and Volatile Evolution (MAVEN) mission has identified the process that appears to have played a key role in the transition of the Martian climate from an early, warm and wet environment that might have supported surface life to the cold, arid planet Mars is today.