NOAO / SCIENCE PHOTO LIBRARY NOAO / SCIENCE PHOTO LIBRARY
This image may not be used to state or imply NOAO endorsement of any company or product.
Optical photograph of M20, the Trifid Nebula, a cloud of gas and dust lying some 3000 light years away in the constellation of Sagittarius. The gas is mostly hydrogen, which glows red because it is excited by ultraviolet radiation from hot young stars lying within it. To the north of the Trifid is a blue nebula which surrounds a bright star known as HD 164514. Although bright, this young star is not hot enough to excite the gas in which it is embedded; the blue light is just starlight reflected by dust particles within the gas.
Model release not required. Property release not required.