Magnetic Storm - Earth's Invisible Shield
From PBS.org and NOVA website: Like the plot of a sci-fi B movie, something weird is happening deep underground where the constant spin of Earth's liquid metallic core generates an invisible magnetic force field that shields our planet from harmful radiation in space. Gradually, the field is growing weaker. Could we be heading for a demagnetized doomsday that will leave us defenseless against the lethal effects of solar wind and cosmic rays? "Magnetic Storm - Earth's Invisible Shield" (55:57) looks into our potentially unsettling magnetic future.