Despite its magnetic field, Earth is losing its atmosphere to space at about the same rate as planets that lack this protective barrier against the solar wind. Scientists now are beginning to question whether magnetic fields really are vital to helping a planet hold on to its atmosphere. Upcoming missions, such as NASA's MAVEN mission to Mars, will help astrobiologists understand how the loss of planetary atmospheres is tied to solar activity. The work could shed new light on how a planet's habitability is effected by its local space environment.
Last Updated: 1 April 2011