March 7th 2013 Sol 208

A natural hazard for all spacecraft, including MSL, is currently at Mars.  On March 5th there was a large solar flare or ‘Coronal Mass Ejection’.  This sent out a stream of plasma from the Sun – which has now reached Mars.  The radiation associated with this could damage active circuitry so Curiosity has been kept in a low activity mode.  Data from our Radiation Asssessment Detector (RAD) instrument will help document the intensity of this solar storm.  It logged radiation levels on the MSL journey to Mars after launch in 2011. 

The thin atmosphere and lack of a dipole magnetic field means that Mars is always directly exposed to this solar weather.  During the Noachian, when Mars did have a magnetic dipole, like the Earth has today, the surface of Mars would have been more protected from solar radiation.  Thats part of the reason many researchers think microbial life might have been possible at that time.