This VLT image of the Thor’s Helmet Nebula was taken on the occasion of ESO’s 50th Anniversary, 5 October 2012, with the help of Brigitte Bailleul — winner of the Tweet Your Way to the VLT! competition. The observations were broadcast live over the internet from the Paranal Observatory in Chile. This object, also known as NGC 2359, lies in the constellation of Canis Major (The Great Dog). The helmet-shaped nebula is around 15 000 light-years away from Earth and is over 30 light-years across. The helmet is a cosmic bubble, blown as the wind from the bright, massive star near the bubble's centre sweeps through the surrounding molecular cloud.
European Southern Observatory/B. Bailleul
CC BY 4.0
<a rel="nofollow" class="external free" href="https://www.eso.org/public/images/archive/top100/">https://www.eso.org/public/images/archive/top100/</a>; see also <a rel="nofollow" class="external free" href="http://www.eso.org/public/images/eso1238a/">http://www.eso.org/public/images/eso1238a/</a>