Big Mars News: Strong Natural Magenetic Sheilds against Solar Wind found on Mars

A major discovery on Mars has suddenly made perhaps the issue of radiation shielding for human explorers on Mars (at least in some major regions of Mars) a non issue, or at least very trivial. Before we discuss the significance of this discovery, let us first review the types of radiation threats faced by any future human Martian explorer:

Types of Radiation Threats

There are three major types of radiation threat faced by any human space traveler:

• Cosmic rays: very high energy particles that bombard us from all directions, this type of radiation is stopped partially by Earth's atmosphere.
  
• Solar Wind: charged, high speed particles are mostly stopped by Earths magnetic field that acts as a natural shield, except when periodically Earth's magnetic field disappears when it flips it's poles, potentially caused by a huge nuclear reactor at it's core (see this Discover issue). For someone standing on the Moon, or any other planet without a magnetic field, when the Sun is not shining on you, there is no Solar Wind hitting you. This type of radiation can deliver lethal doses (large enough doses to severely damage DNA leading to death buy radiation burn or cancer within a few years) to an unprotected astronaut in a very short period of time.
  
  
• Ultraviolet light: Earth's high-altitude atmospheric Ozone provides us some protection against UV; humans still have to watch out for the danger- contrary to a popular misconception, even a substantially dark-skinned person can get a bad sun-burn on a typical sunny day on the beach. Without the Ozone this problem would be much worse. The good news is that the UV light reaching Mars's upper atmosphere is already half of Earth, and there is some Ozone on Mars. Due to the very low density of the atmosphere, currently it is impossible for people to walk on Mars without a spacesuit, so getting a burn because of lying naked on a Martian beach is impossible - you will die because of lack of pressure and oxygen before that. With minor UV shield on their spacesuit face-plates, this type of radiation is really not an issue on Mars. Even greenhouses can be designed to have UV shielded plastics.
  

Vast naturally magnetic shielded regions found on Mars

It was known before Mars Global Surveyor reached Mars, that Mars lacked a strong magnetic field, and people kept gloating about how the solar wind creates a "sterile super-toxic environment" on the surface of Mars making any surface life impossible, and why unless we solve this issue, this was at least one major unsolved problem for long-term manned missions on the surface of Mars.
Here is an interesting discussion from three years ago posted on Austin Mars Society's mailing list.

Since 1997 Global surveyor has found vast regions of strong magnetic fields on Mars.

The most IMPORTANT piece of detail in this news is that large swath's of Mars have magnetic field with strength comparable to Earth's, thus are likely to provide strong natural protection against Solar Wind to astronauts in these regions of Mars. In fact the fields are so powerful that they actually cause auroras on Mars just like on Earth. This is amazingly good news for mission planners currently planning manned missions to Mars - a solution to a major issue that even we could not have imagined, at least for some regions of Mars :-)