In 1774 the famous astronomer William Herschel declared ‘Hier ist wahrhaftig ein Loch im Himmel!’*. At the time he was observing a dark area within the constellation of Scorpio , believing it to be completely devoid of stars.
Dark patches like these, often reveal beautiful cosmic views when telescopes observe them in longer wavelength radiation than light; for example the telescope APEX, which is in Chile. APEX is the world’s largest single-dish submillimetre wavelength telescope and its spectacular images of the Orion Molecular Cloud complex reveal that some of these dark patches glow a bright orange – as if they have been set on fire. This cloud complex is 1500 miles away from the Earth in the Orion constellation, and is the closest region of massive star formation to us. These images show bright colours under longer wavelengths representing young stars and star-forming nebulae which are covered up in visible light due to the density of cosmic dust residing in these regions in front of them.
However Herschel was not completely wrong as even when some of these regions are illuminated by APEX images, they still exhibit dark patches and are in fact holes in the sky.
*Truly there is a hole in the sky here!’
