Like space shuttle pilots, Mars navigators need to know what the atmosphere will be like during landing. When Phoenix arrived, it barely missed a dust storm. Now scientists are evaluating what conditions may be like when the Mars Science Laboratory rover arrives in two years. That's one Mars year, or one change of seasons.
Just like on Earth, temperatures vary depending on the weather and the season. Temperature changes affect the density of the atmosphere. Density, in turn, determines how much a spacecraft will slow down. Instruments orbiting Mars are keeping tabs on temperature. This information is critical, because it tells engineers when to open the parachutes and fire the retrorockets.
Scientists predicted clear skies on landing day. Following a recent dust storm, skies above Phoenix's destination (white star) were mostly clear but somewhat dusty (green). Continued measurements will help future missions land safely, too.
Mars Climate Sounder, Mars Reconnaissance Orbiter
Image credits: NASA/JPL-Caltech