Here There Be No Dragons : Curiosity Finds Mars Radiation Levels Comparable to ISS

Daily Fluctations in Mars Radiation
Credit NASA / JPL

Early in the age of exploration under sail, mapmakers sometimes colored in the boundaries of the unknown with the cryptic warning, “here there be dragons.”  While the only Dragons seen lately are definitely of the friendly variety,  dire warnings of the risks of radiation on Mars have served as a similar precautionary tale for those who would take the first available flight to the Red Planet.

Now, JPL’s Mars Curiosity Rover is beginning to send back some interesting data regarding the local weather at Gale crater, and it is highly encouraging.  By combining information from the rover’s Environmental Monitoring Station Instrument with its Radiation Assessment Detector,  scientists are learning that during the course of the day, as the sun warms and expands the  planet’s atmosphere, radiation levels tends to drop by three to five percent.  The overall trend appears to be seasonal, with the atmosphere itself becoming denser as the Martian spring turns into summer, releasing  frozen CO2 from the southern ice cap.

The most critical observation however, is that the overall radiation environment on the planet’s surface, at least to this point in the mission, appears to be roughly comparable with that encountered by astronauts aboard the International Space Station in low Earth orbit.

For those who advocate for settling Mars early and often,  confirmation of these observations, accompanied by the publishing of hard numbers expected in a few months, might just be the equivalent of a get out of jail free card for the human race.   Compared to ISS, Mars offers the obvious advantage of ample local material for habitat shielding.  The real benefit contained in the apparent findings for future explorers and settlers would be the freedom to engage in unshielded surface operations under an understood and  acceptable risk level.

During the course of its mission, continued weather and radiation monitoring from Curiosity will help paint a much clearer picture of local and planetary conditions, providing specific information which can be used to help determine what an annual  surface exposure allowance might look like, including the best time of day for such work.  For the moment,  it appears to good  news for those who prefer to sleep late, and do the yardwork  in the afternoon.