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.

September 14, 1999 The Colourful Orion Nebula Credit: Gary Bernstein (U. Michigan); Copyright: U. Michigan, Lucent

Explanation: The Great Nebula in Orion is a colourful place. Visible to the unaided eye as a fuzzy patch in the constellation of Orion, this image taken with the Big Throughput Camera shows the Orion Nebula to be a busy neighbourhood of young stars, hot gas, and dark dust. The power behind much of the Orion Nebula (M42) is the Trapezium - four of the brightest stars in the nebula. The eerie blue glow surrounding the bright stars pictured here is their own starlight reflected by nearby dust. Hot oxygen and hydrogen gases cause the extended green and pink glows, respectively. Dark brown dust filaments cover much of the region. The whole Orion Nebula cloud complex, which includes the Horsehead Nebula, will slowly disperse over the next 100,000 years.