The Visible and Infrared Survey Telescope — VISTA

This photograph from 2008 shows the VISTA telescope, which is currently completing tests in its dome at Paranal in Chile. VISTA, along with the VST (VLT Survey Telescope) is one of two ESO survey telescopes about to start work surveying the southern skies.

VISTA has a main mirror that is 4.1 metres across and is by far the largest telescope in the world dedicated to surveying the sky at near-infrared wavelengths. It was conceived and developed by the United Kingdom and became an in-kind contribution to ESO as part of the UK's accession agreement, with the subscription paid by the UK Science and Technology Facilities Council (STFC). The main mirror is the most highly curved mirror of its size ever made and at the heart of VISTA is a 3-tonne camera containing 16 special detectors sensitive to infrared light with a combined total of 67 megapixels. It will have widest coverage of any astronomical near-infrared camera.

Observing at wavelengths longer than those visible to the human eye will allow VISTA to study objects that may be almost impossible to see in visible light because they are cool, obscured by dust clouds or because their light has been stretched towards redder wavelengths by the expansion of space during the light’s long journey from the early Universe.

VISTA will be able to detect and catalogue objects over the whole southern sky with a sensitivity that is 40 times greater than achieved with earlier infrared sky surveys such as the highly successful Two Micron All-Sky Survey. The start of VISTA surveys is planned for the second half of 2009.

This view looks down the stubby tube of VISTA. The white tubular structure in the foreground is the support for the secondary mirror and, just below the centre of the picture, the camera, complete with a light blue corrector lens, can be seen. The blue structure at the bottom is part of the telescope’s fork mount.