Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2013 January 10



Explanation: Cosmic bullets pierce the outskirts of the Orion Nebula some 1500 light-years distant in this sharp infrared close-up. Blasted out by energetic massive star formation the bullets, relatively dense, hot gas clouds about ten times the size of Pluto's orbit, are blue in the false colour image. Glowing with the light of ionized iron atoms they travel at speeds of hundreds of kilometres per second, their passage traced by yellowish trails of the nebula's shock-heated hydrogen gas. The cone-shaped wakes are up to a fifth of a light-year long. The detailed image was created using the 8.1 metre Gemini South telescope in Chile with a newly commisioned adaptive optics system (GeMS). Achieving a larger field of view than previous generation adaptive optics, GeMS uses five laser generated guide stars to help compensate for the blurring effects of planet Earth's atmosphere.