High Anxiety: Sudden solar flare highlights space risks
By Sid Perkins
Measurements of energetic particles from an unusually strong solar flare that pummeled Earth early this year suggest that astronauts traveling or working in space might sometimes need to reach shelter within minutes of a warning.
The Jan. 20 episode was the last and most powerful event in a 6-day series of flares (SN: 2/12/05, p. 109: Available to subscribers at Proton storm erupts from the sun). Although the energy emitted by the final flare came nowhere near to setting a record, the cascade of particles that spewed from the sun took a path to strike Earth with almost unprecedented force and speed. That beam included the highest concentrations ever directly measured of protons packing more than 100 million electron-volts (MeV) of energy, says Richard A. Mewaldt of the California Institute of Technology in Pasadena. Such protons can bore through the human body, wreaking biochemical damage along the way.