Earlier this week, Earth experienced the most intense solar radiation storm in more than two decades. The storm produced spectacular auroras visible far beyond their usual latitudes.
On January 18, an active region on the Sun unleashed an X1.9-class solar flare, one of the strongest types. A coronal mass ejection (CME), in which the sun expelled billions of solar particles, quickly followed.
The CME and X1.9-class flare happened to be directed toward our planet. As it slammed into our magnetosphere, the charged particles disrupted the magnetic field around Earth so much that the charged solar particles made it into our atmosphere. The particles’ interactions with atmospheric gases produce the colorful auroras.
The solar radiation storm has been graded S4, the strongest recorded since the solar storms of October 2003. The NOAA’s Space Weather Prediction Center confirmed that this level marks the highest radiation storm in over 20 years. It can impact aviation, satellites, and even astronauts in space. On Earth, this geomagnetic storm is powerful enough to disrupt power grids.
Photo: Jerry Kobalenko
Astronauts took shelter
As solar radiation storms consist of energetic particles that can penetrate spacecraft electronics and pose hazards to humans in space, the astronauts on the ISS prudently moved into certain sections of the station with increased shielding.
For those of us on Earth, the most visible effect of this storm was the Northern Lights (and, in parts of the Southern Hemisphere, the Southern Lights). Typically, these are only seen at high latitudes, peaking around 60° latitude. But this week, the waves of green, pink, and red light appeared as far south as Southern California and across large swathes of Europe.
Photo: Jerry Kobalenko
Though the storm has mostly passed, more flares directed toward Earth may hit next week.
