The Rho Ophiuchi Dark Cloud

At a distance of about 400 light-years, the Rho Ophiuchi molecular dark cloud is one of the closest star-forming regions to Earth. The cloud is located in the constellations of Scorpius (the Scorpion) and Ophiuchus (the Serpent Bearer).

Surrounding the star known as ρ (Rho) Ophiuchi, this remarkable giant cloud is rich in molecular hydrogen and shows exceptionally vivid star formation features. Surrounding gas and dust hides most of the stars in visible light, though the latest X-ray and infrared studies have unveiled more than 300 newborn stars in the central nebula region. These observations have shown that most of the stars are about 300 000 years old. Over time, the hydrogen-filled dust clouds in the area will shrink under their own weight to form more new stars. This region owes its blue colour to the reflection of the light from the hot, young stars on the dust cloud.