Great Orion Nebula
Great Orion Nebula or Orion Nebula, or M 42, diffuse nebula , or cloud of gas and dust, located in the constellation Orion. With its brightest parts having an apparent magnitude (a measure of brightness as seen from the earth) of 4.0, the Great Orion Nebula can be seen with the unaided eye as part of Orion’s sword, which hangs from his belt. The Great Orion Nebula looks like a star when it is seen with the unaided eye, but even a small telescope reveals its cloudy nature. The entire Great Orion Nebula as seen from the earth is about 60 arc minutes wide, or about four times as wide as the full moon. The Great Orion Nebula is about 1500 light-years from the earth and it is about 30 light-years in diameter. Unlike some diffuse nebulae, which are visible only because they reflect the light of nearby stars, the Great Orion Nebula not only reflects light, but it also emits light. Emission nebulae like the Great Orion Nebula are so huge that they provide enough gas and dust to create new sta...