Snapped using their 2.2-metre MPG/ESO telescope, the superb image above was released this week by the European Southern Observatory, showing part of the Milky Way in Ophiuchus, the much neglected thirteenth zodiac sign.
Darkness in the sky can represent an absence of stars. But when marked out against a forest of stars such as this, it indicates dark molecular clouds that block out the light of everything behind them from our point of view. This particular dust cloud is known as LDN1774 and like other molecular clouds, it is only a few degrees warmer than absolute zero. It is from these clouds that future generations of stars will form. As Ursula K. Le Guin wrote: only in darkness, light.
The ESO also provided these images below of a similar molecular cloud 500 light-years away, Barnard 68, in visible and infrared light, showing that some longer wavelength light from the stars behind can get through.
Credit: ESO. Barnard 68 in visible light
Credit: ESO. Part of Barnard 68 by infrared.
While European and Asian astronomers were seeing patterns in the stars, Indigenous Australians made out the shape of an emu, not from the stars but from the darkness, including clouds like LDN1774 and Barnard 68 that hide parts of the Milky Way from our sight.