Surface Radiation Levels
Without a Global Magnetic Field, and only a thin atmosphere, Mars is constantly bombarded by the Sun's radiation and the solar wind.
The Martian surface is exposed to 2.5 times more radiation than Earth.
Image above : Earth's atmosphere protects the surface from most dangerous radiation. Note visible light and infrared radiation reach the surface.
Life on Mars?
Some scientists believe that radiation levels on the Mars surface today would be inhospitable for microbial life. Though not totally impossible.
In 2007 researchers identified a strain of bacteria on Earth that are "extremely resistant to ionizing radiation, they laugh at ultraviolet light, extreme, heat, cold and they don’t mind being completely dried out for long periods. Bathed in acid? Boring." Read more about the genus Deinococcus.
Human explorers would need to be shielded against such high levels of radiation, and any long-term colonists on Mars would have to live underground - protected from dangerous radiation by a layer of Martian soil.
The VSSEC Mars Rover has an instrument mounted on the end of the Robotic arm to take local radiation readings - the APXS (Alpha-Particle-X-Ray-Spectrometer).
The Space Weather Scientist will negotiate with the engineering team to deploy the APXS to take an initial background radiation reading, and again at regular intervals to identify any fluctuations. Alert the Chief Scientist and other members of Mission Control if radiation levels rise.