In the late eighth century, Earth was hit by a mystery blast of cosmic rays, according to a Japanese study that found a relic of the powerful event in cedar trees.
Earth was hit by a mysterious blast of cosmic radiation at some point during the 8th century AD.
Scientists in Japan have been able to learn of the incident through the examination of ancient cedar trees which contain carbon-14, an isotope derived from cosmic radiation. The research found that around that time the levels of carbon-14 were 1.2% higher than usual, indicating a significant event such as that produced by a massive solar flare or supernova.
"With our present knowledge, we cannot specify the cause of this event," said Fusa Miyake of Nagoya University. "However, we can say that an extremely energetic event occurred around our space environment in AD 775 ... (but) neither a solar flare nor a local supernova is likely to have been responsible."
Source Associated Press
