A Monday post at the Physics arXiv blog reports that a natural phenomenon on the moon may hold the key to protecting astronauts on long term deep space mission from radiation. Beyond the Earth’s magnetic field, particles from the sun as well as sources from across interstellar space can rip through the DNA of astronauts, disrupting the code for cell reproduction, leading to diseases such as cancer. Shielding astronauts from this kind of threat is a prerequisite before humans can go to destinations such as Mars.
There are features on the moon’s surface called “lunar swirls” that stand out as whitened patches that are brighter than the surrounding areas. Scientists have puzzled over these swirls for years. But now they theorize that the lunar swirls are sources if weak magnetic fields that deflect radioactive particles from darkening the surface.
It turns out that even relatively weak magnetic fields will deflect radioactive particle. This is because that in a space ship headed for Mars, the fields would sweep plasma particles before them, warding off the radiation. For the occasional solar storm, some kind of has such as xenon could be pumped out to augment the magnetic shield.
Researchers have been studying the idea of using magnetic deflector shield to protect astronauts for some time. This study suggests that the amount of power that it would take to produce such a field would be relatively small, about 16 kilowatts plus an extra five for cooling and control systems. The whole deflector shield system would mass about 1.5 metric tonnes.
Of course there is a distance between the theory and getting down to actual engineering. NASA and other space agencies, not to mention some private groups, considering plans to send explorers beyond low Earth orbit. The fact that protection against radiation will take less power than hitherto had been thought will bring the long dreamed of age of interplanetary exploration closer to reality.