Magnetic Tornadoes Could Liberate Mercury´s Atmosphere

As the closest planet to the sun, Mercury is scorching hot, with daytime temperatures of
more than 800 degrees Fahrenheit (approximately 450 degrees Celsius). It is also the
smallest rocky planet, so its gravity is weak, only about 38 percent of Earth's.

http://www.alienskys.com/2009/Magnetic_Tornadoes_Could_Liberate_Mercurys_Tenuous_Atmosphere_2620.html