Context of Expel
The most powerful solar storm ever may have hit Earth 14300 years ago, according to records preserved in Alpine tree trunks. It is unclear how much damage a similar storm might cause today, but electricity grids could theoretically be knocked offline for months and all satellites destroyed.
In 2012, Fusa Miyake at Nagoya University in Japan discovered evidence in tree trunks of very powerful solar flares — charged particles expelled from the sun that, along with magnetized plasma and gamma rays, make up solar storms. These flares, which date back many centuries, may have caused a spike in the level of a radioactive form of carbon in trees.
–New Scientist