The VISTA (Visible and Infrared Survey Telescope for Astronomy) is a wide-field reflecting telescope with a 4.1 metre mirror, located at the Paranal Observatory in Chile. It is operated by the European Southern Observatory and started science operations in December 2009. VISTA was conceived and developed by a consortium of universities in the United Kingdom led by Queen Mary University of London 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). VISTA is a survey telescope working originally at infrared wavelengths, and was the largest telescope in the world dedicated to surveying the sky at near-infrared wavelengths. From 2009 - 2023 the telescope had only one instrument: VIRCAM, the Vista InfraRed CAMera. This is a 3-tonne camera containing 16 special detectors sensitive to infrared light, with a combined total of 67 million pixels. A second-generation instrument called 4MOST, a 2400-object fibre-fed multi-object spectrograph, was installed in 2024-25 and started operations at the telescope in 2026. Observing at wavelengths longer than those visible to the human eye allowed 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.
4MOST The new 4MOST multi-object spectrograph saw first light on VISTA in October 2025, starting science operations in 2026, planning for 5+ years of operation. Key components of 4MOST are a new 4-lens wide-field corrector giving a hexagonal science field of 2.5 degrees diameter; a fibre-positioner with 2436 individually movable fibre-optic spines, and three spectrographs mounted on the telescope base: 1624 fibres are routed to two medium-resolution spectrographs covering the full visible wavelength range 370-950 nm, while 812 fibres go to one high-resolution spectrograph covering three smaller wavelength windows of blue, green and red light. Additional hardware includes 4 metrology cameras, new active-optics cameras and calibration sources. Medium and high-resolution observations are simultaneous; typical exposures are 20-30 minutes length, with repeated visits for fainter objects. 4MOST will cover the entire Southern hemisphere sky with several visits to each location over the first 5 years, while fibres are shared out between many distinct science projects in each pointing. Projects include followup of targets from space missions including GAIA, eROSITA and PLATO, plus supernova discoveries from Rubin Observatory and others.
Project history VISTA carried out surveys of the southern sky at near infrared wavelengths. Such surveys should both return direct scientific results and help select objects for further studies with larger telescopes. There are two related projects: the Wide Field Camera (WFCAM) on the United Kingdom Infrared Telescope in Hawaii carries out infrared surveys of the northern sky, and the VLT Survey Telescope in Chile carries out surveys of the southern sky in visible light.
The project was initiated in 1999 by the VISTA Consortium of 18 universities in the United Kingdom (UK), which obtained funding from a joint infrastructure fund of the UK government and further funding from the Particle Physics and Astronomy Research Council. The project is valued at €46M (£36M). After considering several sites in Chile, the consortium chose the Paranal Observatory of the European Southern Observatory (ESO), namely a secondary peak 1,500 m from the Very Large Telescope (VLT). The consortium selected the UK Astronomy Technology Centre to take technical responsibility for design and construction of the telescope. Two years later – in 2002 – the UK joined ESO, and VISTA became an in-kind component of the joining fee. The consortium then completed the construction and commissioning of the telescope, and the Science and Technology Facilities Council – on behalf of the UK – handed over the telescope to ESO, for the benefit of astronomers in all its member countries.
VISTA Surveys The scientific goals of the VISTA surveys, which started in 2010, include many of the most exciting problems in astrophysics today, ranging from the nature of dark energy to the threat of near-Earth asteroids. From 2010-2017 six large public surveys were conducted by VISTA: UltraVISTA, VISTA Kilo-Degree Infrared Galaxy Survey (VIKING), VISTA Magellanic Survey (VMC), VISTA Variables in the Via Lactea (VVV), VISTA Hemisphere Survey (VHS), VISTA Deep Extragalactic Observations Survey (VIDEO). These will take up the majority of the observing time in the telescope's first five years of operations. The surveys cover different areas of sky to different depths to attack a wide range of scientific questions. More information about each of the VISTA surveys can be found on the ESO — VISTA Surveys website and in the ESO — Public Surveys Projects webpage. From 2016-2022 a further six public infrared surveys were conducted: UltraVISTA extension, VVVX (extension of VVV), VEILS (VISTA Extragalactic Infrared Legacy Survey, extension of VIDEO); SHARKS (Southern H-ATLAS Regions K-band Survey), VINROUGE (gravitational wave event followup) and GCAV (Galaxy Clusters at VIRCAM). All datasets are available via the ESO archive.
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