In August of 1972 one of the largest Solar Proton Events (SPEs) ever recorded crossed paths with Earth between the Apollo 16 (April 1972) and Apollo 17 (December 1972) missions to the moon. Simulations of the radiation levels an astronaut would have experienced during this SPE indicate that lethal levels would have been absorbed within 10 hours.

Image of the sun from the SOHO spacecraft of the intense solar activity taken May 15, 2005: Image of the sun from the SOHO spacecraft of the intense solar activity taken May 15, 2005Courtesy NOAA

The journal Space Weather warns that significant gaps in our current understanding and monitoring of space weather make a manned mission to Mars too dangerous for the astronauts. Satellites have been able to give advanced warnings of these SPEs, and the Coronal Mass Ejections (CMEs) that precede them, but this monitoring covers only a very small part of our solar system — only the line between the Earth and the Sun. A mission to Mars will cover significant distances that are currently not monitored. Current manned missions, like the space shuttle and International Space Station, take place in low-Earth orbits and are therefore protected from these CMEs and SPEs by Earth's magnetic field.

Scientists and engineers are working on developing new shielding plans for spacecraft to take people to Mars that are designed for protecting astronauts from high radiation levels. Still, only advance warning of these events would provide astronauts with enough time to retreat into protected areas.

University of Warwick researcher Dr Claire Foullon recommends a pre-mission launch of three satellites designed to provide space weather alerts for the Mars spacecraft crew. She also recommends that a warning device be carried aboard the spacecraft.

Earth's magnetic field protects us from solar events most of the time. However, there are times when particles do reach Earth. When blasts of solar particles arrive at the poles they can produce aurora borealis. They can also cause magnetic storms that can damage satellites and impair radio communications and navigation systems.

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Anonymous's picture
Anonymous says:

Space weather is cool!\r\n

posted on Fri, 03/31/2006 - 12:51pm

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