Did you know? The skies over the ESO sites in Chile are so dark that on a clear moonless night it is possible to see your shadow cast by the light of the Milky Way alone.

VISTA Name: Visible and Infrared Survey Telescope for Astronomy (VISTA) Type: near-infrared survey telescope Aperture: 4.1 m Optical design: modified Ritchey–Chrétien with corrector Field of view: 1.65 degree diameter Mounting: altazimuth fork Location: Paranal, on a peak close to the main summit Housing: conventional rotating dome Start of operations: 2009 Wavelength range: 0.84–2.5 microns Instrumentation: NIRCAM ― 8k x 8k mosaic near-infrared camera Detectors: 16 CCDs: 2048 x 2048 pixel infrared (Raytheon VIRGO HgCdTe) Pixel scale: 0.34 arcseconds/pixel Science goals: galaxies in the young Universe, the Magellanic Clouds, variable objects, dark energy, low-mass stars, galaxy evolution

VST Name: VLT Survey Telescope (VST) Type: optical survey telescope Aperture: 2.6 m Optical design: modified Ritchey–Chrétien Field of view: 1 degree diameter Mounting: altazimuth fork Location: Paranal summit adjacent to VLT Housing: conventional rotating dome Start of operations: 2011 (planned) Wavelength range: 0.30–1.00 microns Instrumentation: OmegaCAM ―16k x 16k CCD mosaic camera Detectors: 32 CCDs: 2048 x 4096 pixels (e2v [formerly Marconi] thinned, low-noise) Pixel scale: 0.21 arcseconds/pixel Science goals: study of dark matter and dark energy, gravitational lensing, searching for quasars, structure and content of the Milky Way

Mapping the sky in the finest detail

Two new and powerful telescopes — the Visible and Infrared Survey Telescope for Astronomy (VISTA) and the VLT Survey Telescope (VST) — are starting their work at ESO’s Paranal observatory in northern Chile. They are arguably the most powerful dedicated imaging survey telescopes in the world and will hugely increase the scientific discovery potential of the Paranal Observatory.

Many of the most interesting astronomical objects — from tiny, but potentially dangerous, near-Earth asteroids to the most remote quasars — are rare. Finding them is like looking for a needle in a haystack. The largest telescopes, such as ESO’s Very Large Telescope (VLT) and the NASA/ESA Hubble Space Telescope, can only study a minute part of the sky at any one time, but VISTA and the VST are designed to photograph large areas quickly and deeply. The two telescopes will spend up to five years performing a total of nine carefully designed surveys and will create vast archives of both images and catalogues of objects that will be harvested by astronomers for decades to come. The Survey Telescopes will have a vital role in preparing the way for future facilities such as the European Extremely Large Telescope (E-ELT) and the James Webb Space Telescope (JWST).

Interesting objects discovered by the Survey Telescopes will form targets for detailed study both by the neighbouring VLT and by other telescopes on Earth and in space. Both Survey Telescopes are housed in domes close to the VLT and share the same exceptional observing conditions as well as the same highly efficient operational model.

VISTA has a main mirror 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 its construction is a formidable accomplishment. 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 by the hugely successful Two Micron All-Sky Survey. The start of VISTA surveys is planned for early in 2010.

The VST is a state-of-the-art 2.6-metre telescope equipped with OmegaCAM, a monster 268 megapixel CCD camera with a field of view four times the area of the full Moon. It complements VISTA and will survey the visible-light sky. The VST is the result of a joint venture between ESO and the Capodimonte Astronomical Observatory (OAC) of Naples, a research centre of the Italian National Institute for Astrophysics (INAF). The VST is expected to become operational at Paranal in 2010.

The scientific goals of the surveys include many of the most exciting problems in astrophysics today, ranging from the nature of dark energy to the threat of near-Earth asteroids. Large teams of astronomers throughout Europe will conduct the surveys. Some of the surveys will cover most of the southern sky while others will focus on smaller areas.

Both VISTA and the VST will produce huge quantities of data — a single picture taken by VISTA has 67 megapixels and images from OmegaCam on the VST will have 268 megapixels. The two Survey Telescopes will produce far more data every night than all the other instruments on the VLT combined. Together the VST and VISTA will produce more than 100 Terabytes of data per year.

Read more

Read more on about this observatory on the ESO Handout in PDF format.