摘要：
What could have been a solar storm of the decade ended up more like a storm in a teacup. Strongest solar storm since 2017 hits Earth but leaves aurora chasers in the dark
The sun erupted on March 22 at 9:45 p.m. EDT (0145 GMT on March 23) with a powerful X-class solar flare and unleashed a barrage of super-hot plasma towards Earth in what is known as a coronal mass ejection (CME).
The energetic onslaught hit our planet at 10:37 a.m. EDT (1437 GMT) on Sunday, March 24, sparking a severe G4-class geomagnetic storm, the strongest solar storm since 2017.
Geomagnetic storms, also known as solar storms, are disturbances to Earth's magnetic field caused by large expulsions of plasma and magnetic fields from the sun's atmosphere in the form of CMEs. The U.S. National Oceanic and Atmospheric Administration (NOAA) ranks geomagnetic storms on a scale running from G1, which can cause an increase in auroral activity around the poles and minor fluctuations in power supplies, up to G5. This most extreme level can cause complete HF (high frequency) radio blackouts on the entire sunlit side of the Earth, lasting for several hours.
