Image Credit & Copyright: Gabriel
Rodrigues Santos
These three bright nebulae are
often featured on telescopic tours of the constellation Sagittarius and
the crowded starfields of the central Milky Way. In fact,
18th century cosmic tourist Charles
Messier cataloged two of them; M8, the large nebula below
and right of center, and colorful M20 near the top of
the frame. The third emission region includes NGC 6559, left of M8 and
separated from the larger nebula by a dark dust lane. All three are stellar
nurseries about five thousand light-years or so distant. Over
a hundred light-years across the expansive M8 is also known as the Lagoon
Nebula. M20's popular moniker is the Trifid. Glowing hydrogen gas creates the
dominant red color of the emission nebulae. But for striking contrast, blue
hues in the Trifid are due to dust reflected starlight.
The broad
interstellarscape spans almost 4 degrees or 8 full moons on the sky.