No. 351, “The Cosmic-Ray Shadow and Coronal Magnetism”, by Frederik Tenholt: Measuring the coronal magnetic field in Antarctica.
No. 350, “Kristian Birkeland”, by Hugh Hudson and Lyndsay Fletcher: Space weather a century ago.
See http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/RHESSI_Science_Nuggets . We publish these at roughly two-week intervals and welcome contributions, which should be related, at least loosely, to RHESSI science.