How to see them
Barely visible to the unaided eye on a dark, moonless night, Messier 16 (Eagle Nebula) and Messier 17 (Omega Nebula) are best seen though binoculars, or low power on a telescope. These two closely-knit patches of haze readily fit within the same binocular field of view.These nebulous splendors are vast interstellar clouds of dust and gas giving birth to young, hot suns. Learn to recognize the Teapot asterism in the western half of the constellation Sagittarius, and it’s fairly easy to star-hop to these summertime attractions. Draw an imaginary line from the star Kaus Austrinus and pass just east (left) of the star Kaus Media to locate M16 and M17 about one fist-width above the Teapot. The Teapot, M16 and M17 are highest up when due south.
As seen from mid-northern latitudes, they bejewel the southern evening sky in summer and early autumn.
The distances to the M16 Eagle Nebula and the M17 Omega Nebula are not known with precision. There is little doubt that these clouds of star formation lie farther away than the more brilliant Great Orion Nebula, the star-forming nebula that’s visible to the unaided eye in the winter sky. When you look at M16 and M17, you’re gazing at deep-sky wonders in the next spiral arm inward: the Sagittarius arm of the Milky Way galaxy.
The M16 Eagle Nebula lies at an estimated distance of 7,000 to 9,000 light-years, and the M17 Omega Nebula is thought to be around 5,000 light-years away. In contrast, the Orion Nebula resides within the Orion spiral arm (the same spiral arm as our solar system) at some 1,300 light-years distant.
Both M16 and M17 have a number of common names. The M16 Eagle Nebula is also called The Ghost or Star Queen Nebula. The M17 Omega Nebula also goes by the moniker Swan Nebula or Horseshoe Nebula.
One of the most famous photographs ever taken by the Hubble Telescope is of an area in M16. The Pillars of Creation photo ranks as a true masterpiece of celestial imagery.
Two other patches of nebulosity – M8 and M20 – also vie for your attention, and couple up together within the same binocular field. Like M16 and M17, this pair resides in the Sagittarius arm and is found by star-hopping from The Teapot. Judge for yourself which pair of stellar nurseries makes the bigger splash!