Credit: NASA/JPL-Caltech/J. Stauffer (SSC/Caltech)
A thunderbird lurks in the dreamy clouds of the Great Nebula in Orion. Also a colony of hot, young stars shines their way through the enveloping folds of dust and gas.
This churning, cosmic scene is from NASA‘s Spitzer Space Telescope. The Great Nebula, also known as M42, is one of the largest star factories in the Milky Way Galaxy and one of the closest to Earth. Only 1,500 light-years from Earth, the nebula is visible to the naked eye in Orion’s sword, just below the three stars that make up the belt. Spitzer views the universe in the near-infrared; meaning basically it “sees” heat while showing most of what we would normally see with our own eyes.
Explore the image. The bright stars in the center are the hot stars called the Trapezium cluster. Radiation and howling stellar winds from these stars are sculpting and lighting the great nebula. The radiation causes the gas to glow.
Note the differences in the image at left of M42 taken from the Hubble Space Telescope. The overall features are the same with the same curling star clouds. Spitzer allows us to view into the dust just a bit more. Being able to do this shows us stars on the verge of being born. Some stars are not visible at all in the Hubble image but stand out clearly when viewed by the Spitzer.
Astronomers will continue to watch for changes in the young stars of Orion. While these young stars are finishing forming, they change in brightness. This could be due to dust clouds moving in front of the stars or the existence of cool spots on their surfaces. These stars are just infant stars; only about a million years old. Our Sun is considered middle-aged at about 4.6 billion years old.