Thor's Helmet

Explanation: Thor not only has his own day (Thursday), but a helmet in the heavens. Popularly called Thor's Helmet, NGC 2359 is a hat-shaped cosmic cloud with wing -like appendages. Heroically sized even for a Norse god , Thor's Helmet is about 30 light-years across. In fact, the cosmic head-covering is more like an interstellar bubble , blown by a fast wind from the bright, massive star near the bubble's center. Known as a Wolf-Rayet star , the central star is an extremely hot giant thought to be in a brief, pre- supernova stage of evolution . NGC 2359 is located about 15,000 light-years away toward the constellation of the Great Overdog . This sharp image is a combination of deep images taken in light emitted by hydrogen (red) and oxygen (blue). The star in the center of Thor's Helmet is expected to explode in a spectacular supernova sometime within the next few thousand years.

Sky Surprise: What picture did APOD feature on your birthday? (after 1995)