The Sun. A bright fiery light in the sky to some, worshipped as a god by others, seen as a massive ball of hydrogen plasma 150 million kilometres away by scientists. Once in a while, the Sun goes ahead and releases massive amounts of charged plasma particles toward the Earth. The particles should eradicate humanity with horrible burns and render our planet lifeless, but luckily… they don’t. Why? The Earth’s magnetic field protects us, funnelling the particles to the poles where they ionize gases in the atmosphere and become harmless. The bonus for humanity, aside from not dying, is that we get to witness the beauty of an aurora.
But some solar storms are larger than others. You may have heard of powerful ones that can knock out electronics in latitudes near the poles, producing aurorae that can be seen far from magnetic north and south. How often do these storms happen? How have they changed throughout history?
For the answers to these and other questions, scientists go to the Earth’s personal time capsules. Ice layers. Scientists from Lund University in Sweden have been looking at the ice layers in Greenland for radioactive Carbon, a tell tale sign of cosmic ray activity from the Galaxy and Sun.
A few years ago, a team of researchers found large deposits of radioactive carbon in old tree rings from the periods AD 774/775 and AD 993/994. The explanation for the large deposits had been up for debate, but with their work on ice cores, the Lund researchers have found similar deposits corresponding to these exact time periods. This confirms that two massive solar storms hit the Earth during these time periods over 1000 years ago.
“If such enormous solar storms would hit Earth today, they could have devastating effects on our power supply, satellites and communication systems,” says Raimund Muscheler at the Department of Geology, Lund University.
Plus, we really don’t have a contingency plan to protect sensitive electronics in the event of a massive solar storm. Though if it does happen, the light show will be incredible…
…too bad our cameras will all be too friend to photograph it.