A hole in the sky

Rather than showing spectacular objects, some of the most surprising images of the Universe instead focus on emptiness. This new image from the 2.2-metre MPG/ESO telescope shows dark tentacles swirling outwards from a dark, blank spot of space in the centre of the frame, particularly conspicuous against the dense peppering of bright gold and red stars across the rest of the image.

This region is not a hole in the cosmos, or an empty patch of sky. The dark lanes are actually made up of thick, opaque dust lying between us and the packed star field behind it. This obscuring dust forms part of a dark molecular cloud, cold and dense areas where large quantities of dust and molecular gas mingle and block the visible light emitted by more distant stars.

It is still unclear how these clouds form, but they are thought to be the very early stages of new star formation — in the future, the subject of this image may well collapse inwards on itself to form a new star system.

Although the cloud in this image is a fairly anonymous resident of the nearby Universe — catalogued as LDN1774 — one of the most famous examples of a molecular cloud is the very similar Barnard 68, which lies some 500 light-years away from us. Barnard 68 has been observed extensively using ESO telescopes, both in visible (eso9924a) and infrared light (eso9934, eso0102a). As shown in these different images, it is possible to probe through dark cosmic dust using infrared light, but visible-light observations such as those shown in this VLT image cannot see beyond the smokescreen.

This image was taken by the Wide Field Imager, an instrument mounted on ESO’s 2.2-metre MPG/ESO telescope at La Silla, Chile.