"Energy goes up... but doesn't come back down! Coronal heating?" by Brian Welsch. 

See 
http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/RHESSI_Science_Nuggets

listing the current series, 2008-present, and

http://sprg.ssl.berkeley.edu/~tohban/nuggets/ 

for the original series, 2005-2008.

We publish these at roughly two-week intervals and welcome contributions,
which should be related, at least loosely, to RHESSI science.