Is our technology safe?

 CMEs: Potential source of energy?

Coronal mass ejections (CMEs) are huge expulsions of plasma and magnetic field from the sun's corona. ( A corona is an aura of plasma that surrounds the sun and other stars. The sun's corona extends millions of kilometers into outer space and is mostly seen during a total solar eclipse).  These colossal waves of solar plasma shoot billions of particles into space at about 1 million miles or 1,600,000 kilometers per hour.⁣ They also release large quantities of matter and electromagnetic radiation into space near the corona, or farther into the planetary system. The magnetic plasma ejected primarily consists of electrons and protons.

⁣Unlike solar flares, which are powerful bursts of radiation that can temporarily cause communications and navigation blackouts, CMEs can temporarily overload electrical systems if power companies are not prepared (you can understand more about solar flares/solar storms here).  CMEs are comparatively slower than solar flares and are associated with enormous changes and disturbances in the coronal magnetic field. 

So, what exactly causes CMEs? It happens when there is a sudden rearrangement of the magnetic field lines when two oppositely directed magnetic fields are brought together. This is called 'magnetic reconnection and the magnetic field lines that reconnect release vast amounts of energy. The lines of force quickly reconnect into magnetic plasma loops and as they get bigger, the tension increases. After a while, they break and give out the energy that we know as 'Coronal mass ejection'. They are much stronger on average.

Because CMEs get blown off the sun in all directions, most don't come anywhere near the Earth. But every so often, an eruption is aimed right at us. When the plasma cloud hits our planet, a geomagnetic storm occurs. The shock wave of charged particles compresses the Earth's daylight magnetic field while the night side gets stretched out. The terrestrial magnetic field eventually snaps back after some time. The onslaught of charged particles and the temporary restructuring of the Earth's magnetic field has many observable effects. 

The northern lights, usually only seen near the poles, can drift to lower latitudes and become brighter. The disturbance of the magnetic field can also expose Earth to deadly cosmic rays. Our atmosphere still provides enough protection for us on the ground but astronauts in space may receive lethal doses of radiation. The real long-lasting danger comes from the ejection's effect on technology. Energy and magnetic activity from CMEs have the potential to severely disrupt power grids, satellites, and communication networks, basically, anything that uses electricity. Cascading failures could quickly shut power down to millions of people in a matter of minutes. Communication networks would fail and GPS satellites, upon which the entire air traffic system relies, would shut down.

Obviously, we don’t want to be surprised by a powerful Earth-bound CME.  That’s why astronomers study the sun. A better understanding of solar activity can help us be better prepared. With even just a few hours of warning before an impending CME strike, we could safely shut down and protect essential services. Disruptions may then only last a few hours, rather than the days, weeks, and months that might otherwise occur. CMEs are just another reminder of how fragile our pale blue planet is as it races around the sun.