This bright cloud of neon colours, a result of the X-ray emissions within, has a strangely distinctive shape — which landed it the name Thor's Helmet among astronomers.
In fact its formal name is NGC 2359, but the central bulge and — squint your eyes now — wing shapes to the left and right got it its name. The bright blue areas are a result of X-ray emissions, while pale red and green regions are a result of ionised hydrogen and oxygen respectively. The image is made up from data acquired by the ESA's XMM-Newton space observatory and Chile's Cerro Tololo telescope. [ESA]