How Space Weather Affects Human Activities
Many phenomena associated with space weather occur within the Earth’s magnetosphere and upper atmosphere. Geomagnetic storms can be accompanied by enhancements in the radiation belts and complex changes in the ionosphere and thermosphere.
When high-energy particles – those moving with enough energy to knock electrons out of atoms – collide with human tissue, they alter the chemical bonds between the molecules that make up the tissue’s cells. Sometimes the damage is too great for a cell to repair and it no longer functions properly. Damage to DNA within cells may even lead to cancer – causing mutations.
During geomagnetic storms, the increased density and energy of particles trapped in the radiation belts means a greater chance that an astronaut will be hit by a damaging particle. That’s why the International Space Station has increased shielding around crew quarters, and why NASA carefully monitors each astronaut’s radiation exposure throughout his or her career.
The magnetosphere and atmosphere keep most harmful radiation from reaching the surface of the Earth, but damaging radiation does penetrate the upper levels of the atmosphere. High-flying airplanes, and those flying over the North Pole, are exposed to more radiation than when at sea level. Geomagnetic storms can also alter the shape of the Earth’s protective magnetosphere, sometimes allowing more high-energy particles into the upper levels of our atmosphere. During these times, people in airplanes face increased exposure to damaging radiation and flights are sometimes rerouted to protect them.
RBSP will help develop better predictive models so that astronauts will have increased warning of storms.
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Most spacecraft in Earth orbit operate partly or entirely within the radiation belts. During periods of intense space weather, the density of particles within the belts increases, making it more likely that sensitive electronics will be hit by a charged particle.
Ions striking satellites can overwhelm sensors, damage solar cells, and degrade wiring and other equipment. When conditions get especially rough in the radiation belts, satellites often switch to a safe mode to protect their systems.
Geomagnetic storms can also:
- Disrupt radio frequency signals as they travel between satellites and ground stations—including Global Positioning Systems and your satellite televisions and car radios. Plasma bubbles (regions of dense ionized gas) form in the atmosphere, and can disrupt a signal passing through them.
- Change the shape of the Earth’s atmosphere so that it moves into the path of satellites that normally fly above it. The increased drag on the satellite slows the spacecraft and changes its orbit, which will need to be corrected.
- Cause electric charges to build up inside spacecraft that overwhelm systems when they discharge.
RBSP will help identify the conditions that can disrupt satellite operations, and lead to the development of better technologies that can withstand, or protect satellites during, geomagnetic storms.
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Large changes in the magnetic field near the Earth’s surface that are associated with geomagnetic storms can induce currents that flow through man-made structures such as railroad systems, power transmission lines, and pipelines. These currents can cause minor disruptions in service, or major problems such as blackouts affecting thousands of people. On Oct. 30, 2003, a geomagnetic storm caused a power failure in Sweden, and on March 13, 1989, six million people lost power when a geomagnetic storm caused a power grid failure in Quebec, Ontario.
RBSP will help develop better predictive models that could give technology operators advance warning of when their systems might be in danger from powerful electric currents induced by space weather phenomena.
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