Astronomy Picture of the Day

Explanation: Few cosmic vistas can excite the imagination like The Great Nebula in Orion. Visible as a faint, bland celestial smudge to the naked eye, the nearest large star-forming region sprawls across this sharp colourful telescopic image. Designated M42 in the Messier Catalogue, the Orion Nebula's glowing gas and dust surrounds hot, young stars. About 40 light-years across, M42 is at the edge of an immense interstellar molecular cloud only 1,500 light-years away that lies within the same spiral arm of our Milky Way galaxy as the Sun. Including dusty bluish reflection nebula NGC 1977, also known as the Running Man nebula at left in the frame, the natal nebulae represent only a small fraction of our galactic neighbourhood's wealth of star-forming material. Within the well-studied stellar nursery, astronomers have also identified what appear to be numerous infant solar systems.