Solar flares on December 21, 2017
The most powerful solar flare in 24 hours
There were no solar flares on the selected date
Solar activity index
Value as of the end of the day on December 21, 2017
Solar X-ray emission over the past 2 days
Chart of solar X-ray emission (1-8 Å) from December 20, 2017 to December 21, 2017
Time zone — UTC+00 (London)
List of solar flares for December 21, 2017
There were no solar flares on the selected date