Observing the corona with two satellites flying in formation, one of which is a Sun-occulting disc.  #space #astronomy 
<br /><a href='https://www.skyatnightmagazine.com/news/esa-proba-3-mission-first-images'>https://www.skyatnightmagazine.com/news/esa-proba-3-mission-first-images</a>