Astrobiologists from the United States and Germany recorded the highest known level of solar UV radiation to reach Earth’s surface. This was around 10 years ago.
On December 29, 2003, the UV Index (UVI) peaked, reaching the blistering number of 43.3 over the Andes Mountains in Bolivia. To put this in context, a beachgoer in the United States would expect a UVI of 8 or 9 on a summer day. Even with an 8 or a 9, one may not escape the day without sunburn.
Nonetheless, it has taken scientists 10 years to detail a report of this data while taking into account all of the variables and anomalies monitored from an international network of dosimeters – or Eldonets (European Light Dosimeter Network) – that measure UV radiation worldwide. This system is comprised of more than 100 stations across 5 continents to account for variation in the atmosphere above each station.