Krioma.net

Credits: ESA/NASA, Yäel Nazé (University of Liège, Belgium) and You-Hua Chu (University of Illinois, Urbana, USA)

The ESA website (http://www.esa.int) describes this as a "celestial geode", I can get what they are trying to say here but the pedantic in me goes, no no no!! What you actually see is a bubble of gas (35 light years across - now that's a huge distance!) which has most likely been created by the intense stellar winds and UV radiation of a hot young star.

For more see: http://www.esa.int/esaCP/SEM37GW4QWD_FeatureWeek_3.html