ESO Announcements

Science ministers visit ESO Headquarters

Tue, 29 Sep 2026 16:00:00 +0200

On 29 September 2026, ministers and secretaries of state from various countries visited ESO’s Headquarters in Garching bei München, Germany. The delegation, led by German Federal Minister of Research, Technology and Space Dorothee Bär, was hosted by ESO Director General Andreas Kaufer.

The visitors included Austria’s Federal Minister for Women, Science and Research Eva-Maria Holzleitner, Ghana’s Minister for Environment, Science and Technology Zanetor Agyeman-Rawlings, Hungary’s Minister for Science and Technology Zoltán Tanács and Kenya’s Principal Secretary for Science, Research and Innovation Shaukat Abdulrazak. The visit provided an opportunity to showcase ESO as a model for international scientific collaboration and for the development of, and long-term investment in, world-class research infrastructure.

The group were welcomed by Kaufer together with ESO’s Directors and staff from across the organisation. During their visit, they learnt about ESO’s facilities in Chile, and about how ESO brings countries, people and institutions together to further our knowledge of the Universe and our ability to explore it. The presentation was followed by an exchange on the benefits and challenges of basic research with Reinhard Genzel, Director of the Max Planck Institute for Extraterrestrial Physics in Germany, whose Nobel-Prize-winning discoveries were made possible by ESO’s facilities.

The delegation also visited ESO’s Technical Building, where instruments and components for ESO’s projects are being assembled and tested before being shipped to Chile. Much of the work there currently centres around ESO's Extremely Large Telescope (ELT), being erected in the Chilean Atacama Desert. The group then visited the ESO Supernova Planetarium & Visitor Centre, where the ministers viewed a planetarium show and explored the exhibition. Additionally, they joined a live connection to ESO’s Paranal Observatory in Chile and experienced the ELT in a virtual environment.

Open House Day: Behind the scenes at ESO on 3 October 2026

Fri, 25 Sep 2026 11:00:00 +0200

On Saturday 3 October 2026, the European Southern Observatory (ESO) will open its doors during the Open House Day of the Garching Research Campus in the north of Munich, Germany. This will be an exciting opportunity to visit ESO and other renowned research institutes for a behind-the-scenes experience, all for free. The ESO Supernova Planetarium & Visitor Centre will also offer planetarium shows and other activities.

From 10:00 to 17:00 CEST, the ESO Headquarters in Garching bei München will open to visitors with a special programme perfect for those with a passion for astronomy and the facilities that make it possible. Discover the science and technology behind ESO’s state-of-the-art telescopes, meet the people working on and with them, and find out how instruments are prototyped and tested. ESO astronomers and engineers will be at the premises all day to answer your questions. ESO will even provide a live connection to Chile, where the organisation’s telescopes are hosted. In short: a perfect Science Day Out!

Share your impressions of the visit online using the event’s hashtags (#TagDerOffenenTür, #EntdeckenCheckenWissen) and by tagging us @esoastronomy on Facebook or Instagram, and @eso.org on Bluesky, and @esosupernova on Facebook and @eso_supernova on Instagram.

Activities overview

Talks, live connection to Chile, and videos: talk live to one of our telescope operators at ESO’s observatories in Chile, listen to astronomers and engineers talk about fascinating science and technology, or enjoy brief videos about ESO and the work we do.
Kids activities: Get your infrared picture taken, build a mini-telescope out of Lego or have a galaxy painted on your cheek. Visit all stations to collect stamps and get a present!
Planetarium shows: Experience a planetarium show in the ESO Supernova Planetarium & Visitor Centre (pre-registration required*)
Inclusive astronomy: Explore star and planet formation through touch
Mechanical workshop: See live machining from raw material to precision parts that will be installed on ESO's telescopes. A number of limited-edition machined mini telescopes will be given away in exchange for a contribution to the ESO Charity Group.

Download the full programme in English (PDF) or German (PDF).

Practical information

All activities are free of charge.
ESO has a cafeteria where a limited amount of food and light refreshments will be available in exchange for a donation to the ESO Charity Group.
Media representatives who wish to attend the event are kindly asked to confirm their participation by contacting press@eso.org.

Notes

During this event, photographs and video recordings will be made. These may contain non-directly identifiable people (e.g. group shots). If you are clearly identifiable, we will obtain your written consent. Read more on the use of this material and your rights in our Privacy Notice (PDF).

Revealing hidden stars and galaxies: new MOONS instrument at the Very Large Telescope makes first observations

Thu, 03 Sep 2026 09:00:00 +0200

ESO’s newest scientific instrument, the Multi-Object Optical and Near-infrared Spectrograph (MOONS) has successfully made its first observations, achieving what astronomers call First Light. Mounted on ESO’s Very Large Telescope (VLT) at Cerro Paranal in northern Chile, MOONS will be able to study 1000 objects at once. It will observe red and infrared light, allowing astronomers to peer into the heart of our galaxy as well as study how distant galaxies formed.

“It is truly emotional to see the First Light of MOONS, a remarkable achievement born from the extraordinary dedication and talent of an exceptional team,” said Michele Cirasuolo, MOONS Principal Investigator and ESO Instrumentation Programme Manager. “MOONS opens a new window onto the Universe, allowing us to explore the physical, chemical, dynamical and environmental properties of millions of stars and galaxies across more than 13 billion years of cosmic history. It will take us to new frontiers in our understanding of how the Milky Way and galaxies have formed and evolved with time. I am incredibly proud of the team and hugely excited to see what new discoveries and new horizons in our understanding of the Universe lie ahead.”

An extraordinary instrument

MOONS — which was built by an international consortium led by the UK Astronomy Technology Centre (UK ATC), part of the Science and Technology Facilities Council (STFC) — is designed to leverage the light-gathering power of one of the VLT’s 8-metre mirrors to observe a multitude of individual stars and galaxies. Using around 1000 optical fibres, each mounted on a robotic positioner, the instrument can point to the exact locations of about 1000 astronomical targets simultaneously and over a large field-of-view. The light collected by the fibres is then fed into two identical spectrographs (with 500 fibres each), which work like a prism creating a rainbow, splitting light into different colours. By analysing the different colours or wavelengths, astronomers are able to reveal many of the cosmic objects’ properties, such as their chemical composition, mass and velocity.

Oscar Gonzalez, MOONS UK Principal Investigator and Head of Project Science and Strategy at UK ATC, said: "MOONS is the result of an extraordinary international effort. For years our scientists, engineers and technicians have worked together to overcome remarkable technological challenges and create an instrument of exceptional capability. For me, First Light is a celebration of their expertise, dedication and perseverance. It marks the exact moment in which years of work are transformed into discovery. MOONS will give astronomers an entirely new way of exploring the Universe, enabling observations that were simply beyond our reach… until now."

MOONS will particularly excel at disentangling how galaxies, including our own, formed and evolved over the history of the universe. The centre of our Milky Way galaxy is ‘hidden’ by cosmic dust, which blocks visible light. By collecting infrared light, MOONS enables astronomers to see through these clouds of dust. Observing in infrared also allows MOONS to monitor distant galaxies. Our Universe is expanding, which means further galaxies are moving faster away from us, which shifts the light we receive from them to longer, predominantly infrared wavelengths. MOONS is the first instrument to allow astronomers to analyse in detail so many objects in this wavelength range at the same time.

To minimise contamination from sources of infrared light around the instrument, the spectrographs of MOONS are housed in a cryostat which keeps them very cold (between –143 and –233 degrees Celsius). As the instrument is 4.5 metres tall, and weighs more than 10 tonnes, this requires 5000 litres of liquid nitrogen to cool it, making the MOONS cryostat one of the largest ever for a ground-based telescope.

First and future observations

MOONS’ first-light observations demonstrated its ability to peer through dust, by targeting stars in the obscured galactic plane. “The first observations highlight the power of MOONS in numbers, sensitivity, quality and multi-wavelength. It allows us to study patterns in otherwise obscured populations, and at the same time, find the ‘odd ones out’ from thousands of stars that will pose new questions to investigate,” says Amelia Bayo, the MOONS Project Scientist at ESO

David Concar, the British Ambassador to Chile and Michele Dougherty, the Astronomer Royal and STFC Executive Chair were at Paranal to witness the first observations, together with ESO’s Director of Operations and future Director General Andreas Kaufer and other ESO and UK ATC representatives. Dougherty said: "Seeing MOONS achieve First Light was tremendously exciting. A landmark moment, not only for the international team behind this remarkable instrument, but for astronomy as a whole. And demonstrates the transformational science that innovative instrumentation can deliver.”

During its ten-year design lifetime, MOONS is expected to observe up to ten million objects, and cover multiple scientific projects at a time. Its advanced technology will benefit two core science aims: to provide crucial spectroscopic follow-up on observations of galaxies, including extremely distant ones, and to deliver precise measurements of velocities and chemical compositions and abundances for millions of stars in the Milky Way. In our galaxy, MOONS will be able to investigate stars up to 40 000 light-years away, including those in dust-shrouded areas, enabling the construction of an accurate 3D map of the Milky Way. MOONS will also unveil the mysteries of early galaxy evolution. As such, it will fill a critical gap in the astronomical toolkit, particularly in the near-infrared.

More Information

The MOONS instrument was designed and built by a consortium of universities and research institutes in Europe and Chile, namely:

Science and Technology Facilities Council's UK Astronomy Technology Centre (UK ATC), United Kingdom (consortium lead)
Centro de Astro-ingenieria UC (AIUC), Pontificia Universidad Catolica de Chile, Chile
ETH Zürich, Switzerland
Galaxies, Etoiles, Physique et Instrumentation (GEPI), Observatoire de Paris-PSL CNRS, France
INAF, Italy
Institute of Astronomy (IoA), University of Cambridge, United Kingdom
Instituto de Astrofísica e Ciências do Espaço (IA), Portugal
Université de Genève, Switzerland

ESO is an associate member of the consortium and provided the sensitive scientific detector systems used by MOONS.

Experience spring at ESO's Paranal Observatory: slots now open for free public tours from October through December

Wed, 02 Sep 2026 16:00:00 +0200

Today, September 2, the European Southern Observatory (ESO) is opening reservations for daytime public tours for the southern-hemisphere 2026 spring season (October through December) at its Paranal Observatory in Chile.

ESO will also offer free round-trip transportation to Paranal from the cities of Antofagasta, in a sporadic manner, and Taltal, once a month, thanks to a collaboration with local public institutions. This initiative aims to provide more options and make it easier for anyone interested in astronomy to participate. In addition, the last night tour of the year at Paranal will take place on October 10. We will announce all the details for registration via our Chile Instagram account @eso.chile over the coming weeks.

This new opening for registrations marks a change in the way ESO operates its public visits programme. Going forward, reservations for each quarter of the year will open during the first week of the month preceding its start. Thus, spots for January, February, and March will open in December; those for April, May, and June in March; those for July, August, and September in June; and those for October, November, and December in September.

ESO has been offering a regular public visit programme to its sites since 1996, attracting more than 7,000 people a year. These changes are being implemented to continue expanding and improving the visitor experience at ESO’s observatories.

During the visit, participants have the opportunity to explore the Paranal Observatory, one of the world’s most important observatories, located in the heart of the Chilean Atacama Desert. As part of the tour, visitors can walk across the Very Large Telescope (VLT) platform and get an inside look at some of its individual telescopes. They also have the opportunity to visit other scientific and support facilities at Paranal, and the Residence, a place of rest for staff working at the observatory.

Key information:

Guided tours are free, but advance registration is required, as space is limited. Large groups are asked to register as far in advance as possible.

You may cancel your reservation on the website until 10:00 a.m. on the Friday before your visit. If you are unable to attend, please cancel your reservation as far in advance as possible so that others may visit the observatory.

All visitors to Paranal (or any ESO facility) must read and sign the Consent Form.

Visits take place during the day. Accommodations at the Visitors’ Residence are not included.

You are not permitted to drive your own vehicle inside the observatory. You must park in the designated area and use the tour bus provided by ESO for the tour.

For safety reasons, visitors with pacemakers are not permitted inside the telescopes. This is because the electromagnetic fields generated by the telescope instrumentation can interfere with the device.

For safety reasons, children under 4 years of age are not permitted to visit the observatory.

Pets are not allowed at the observatory.

Minors must be accompanied by an adult, who may be responsible for a maximum of 10 minors.

Please note that the tour may be cancelled in the event of adverse weather conditions. If this occurs, you will be notified by phone or email as far in advance as possible.

Registration for weekend public tours in October, November, and December is available at the following link.

Andreas Kaufer starts as new ESO Director General

Tue, 01 Sep 2026 14:00:00 +0200

Today, 1 September 2026, Andreas Kaufer began his term as ESO's Director General. Kaufer takes up the role as the construction of ESO’s Extremely Large Telescope (ELT) approaches its final stages, ALMA undergoes a major upgrade, and ESO begins the search for its next programme. He succeeds Xavier Barcons, who has served as ESO’s Director General from 2017 until the end of his term on 31 August 2026.

Kaufer says: “My priorities for the next five years are very clear. First, we will focus on successfully completing and commissioning the ELT. But for me the ELT is not the end of a journey, it's the beginning of a new chapter. It will spark a revolution in observational astrophysics, and we cannot even anticipate what we are going to discover. In parallel we will work towards maximising the scientific return of all our ESO facilities in a safe, efficient and effective way to ensure that they can run for many decades to come. My goal is to prepare ESO for the future beyond the ELT First Light. We will achieve that by investing into our people and in technology and by thinking about the next generation of scientific opportunities.”

Kaufer, ESO’s ninth Director General, brings a wealth of experience in astronomical research, instrumentation and operational management to the role. He obtained a PhD in Astronomy from the Heidelberg University in 1996, and subsequently worked at the Heidelberg State Observatory, where he conducted research on the atmospheres of massive stars and the chemical evolution of galaxies, while also developing and building astronomical instrumentation. Kaufer joined ESO in 1999 as part of the science operations group contributing to bringing the newly built Very Large Telescope into operation. He became Director of the La Silla Paranal Observatory in 2006 and was appointed ESO’s first Director of Operations in 2008.

Now as Director General, Kaufer intends to keep enabling the highest-quality science with ESO’s world-class staff, telescopes and instruments, allowing the best possible astronomical observations.

“What makes ESO truly special to me is its ability to bring together countries, people and an extraordinary breadth of expertise. Together, we are achieving things that no single country could accomplish alone. It is a unique combination of scientific ambition, engineering excellence, operational expertise and long-term vision,” says Kaufer. “This is only possible thanks to the continued support of our 16 Member States and our host country, Chile. I look forward to working with them, and with the entire ESO community, as we take on the exciting challenges and opportunities ahead.”

Ximena Lincolao, Chile's Minister of Science, Technology, Knowledge, and Innovation, visits ESO's Paranal Observatory

Wed, 26 Aug 2026 16:00:00 +0200

On Tuesday August 25, 2026, Ximena Lincolao, Chile’s Minister of Science, Technology, Knowledge, and Innovation, visited ESO’s Paranal Observatory in Chile’s Antofagasta Region. The minister was accompanied by Héctor Bravo, the Science Regional Ministerial Secretariat of Antofagasta.

During the visit, they toured the construction site of ESO’s Extremely Large Telescope (ELT) and learned about the operations of ESO's Very Large Telescope (VLT). The Chilean officials were welcomed by Itziar de Gregorio-Monsalvo, ESO’s Representative in Chile, and by Andreas Kaufer, Director of Operations and future Director General of the Organization.

“Minister Lincolao’s presence at the ELT construction site allows us to share firsthand the progress being made on the world’s largest ‘eye’ for observing the universe. Furthermore, we reaffirm the strength of a decades-long partnership between ESO and Chile, founded on the exploration of the universe, international cooperation, the training of local talent, and the country’s scientific and technological development”, said Itziar de Gregorio-Monsalvo regarding the visit by the minister and the regional authority on the matter.

The visit began with a tour of the ELT construction site at the summit of Cerro Armazones. After learning about the progress of the project for what will be the world’s largest optical and infrared telescope, Minister Lincolao travelled to the Paranal Observatory Residencia, where she toured part of the facilities and held a meeting with Andreas Kaufer, just days before he is set to take office as ESO’s Director General in September.

Later, Minister Lincolao toured the platform housing the telescopes that make up ESO’s VLT, at the summit of Cerro Paranal. The minister entered one of the telescopes and met some of the ESO staff responsible for maintenance and scientific operations.

This visit follows Minister Ximena Lincolao’s trip last July to ESO’s headquarters in Garching, Germany. This series of meetings reaffirms the close bilateral relationship between ESO and Chile, a collaboration that has lasted for more than 60 years.

ALMA upgrade: ESO signs contract for advanced processor

Mon, 24 Aug 2026 14:00:00 +0200

Last week, at a virtual ceremony, ESO signed an agreement with the French National Centre for Scientific Research (CNRS) for the development of a wideband intermediate frequency processor (WIFP) for the Atacama Large Millimeter/submillimeter Array (ALMA). ESO’s Eric Villard and Martin Zwaan of the ALMA Development Team at ESO, as well as Elizabeth Humphreys, European ALMA Programme Manager, were present at the ceremony. From Bordeaux (France) Sean Raymond, Benoit Lavraud and Benjamin Quertier-Dagorn were at the signing, together with Álvaro González, the ALMA Deputy Director of Development, based at the Joint ALMA Observatory in Chile.

ALMA, located in Chile’s Atacama Desert, is currently undergoing a major revamp dubbed the Wideband Sensitivity Upgrade, aimed at keeping the array at the technological cutting edge. The upgrade encompasses most components of the array, from updates to the electronics in the 66 antennas to changes in the correlator (the supercomputer where the signals from the antennas are combined) and fibre-optics systems. The upgrade will increase ALMA’s observing bandwidth, that is, the range of frequencies in which it can observe simultaneously, by a factor of 2 in a first stage and 4 when finalised. It will also significantly improve the sensitivity of ALMA, meaning astronomers will be able to probe fainter and more distant objects, faster.

ALMA antennas capture signals from the cosmos with wavelengths in the millimetre and submillimetre range, equivalent to frequencies of tens of gigahertz to one terahertz. Because these frequencies are very high, they are converted to lower ‘intermediate frequencies’ (IF) that can be more easily processed. The WIFP project aims to develop and deliver the equipment needed to digitise the analogue IF signals from the antennas and prepare them for transportation to the correlator, where the signals are combined. The WIFP is, therefore, a critical component of the Wideband Sensitivity Upgrade.

As the European partner in ALMA, ESO is responsible for a significant part of the upgrade. The WIFP project is one of Europe’s most significant contributions to the upgrade. It will provide each ALMA antenna with digitisation of the receiver signals, digital signal processing, high-precision timestamping of the signals, and total power detection. Compared to the existing system, the signal will be sampled at a rate — 40 billion samples per second — that is ten times higher than at present.

Overall, the WIFP will significantly enhance ALMA data throughput and observing efficiency and can be compared to adding six antennas in terms of efficiency. The processor is developed in a collaboration between ESO and the Laboratoire d’Astrophysique de Bordeaux, part of the University of Bordeaux and CNRS, and is anticipated to be completed in mid 2028.

More information

ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSTC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ.

Ximena Lincolao, Chilean Minister of Science Technology, Knowledge, and Innovation, visits ESO Headquarters

Fri, 10 Jul 2026 16:45:00 +0200

Today, 10 July 2026, the Chilean Minister of Science, Technology, Knowledge, and Innovation, Ximena Lincolao, visited ESO’s Headquarters in Garching bei München, Germany together with a small delegation. The visit, the second by a Chilean Science Minister in just two years, marks the first time the new Minister, who took office just a few months ago, visits ESO’s premises. It underscores the close collaboration between ESO and Chile, which remains vibrant and strong since the organisation and the country first signed a partnership agreement more than 60 years ago.

The visitors were welcomed by ESO Director General Xavier Barcons, ESO Director for Science Jarle Brinchmann, ESO Director of Engineering Sara Krauss, ESO Director of Programmes Adrian Russell and ESO’s Institutional Affairs Officer Beatrice Kioko. During the visit, Minister Lincolao had the opportunity to learn more about ESO’s development activities in Germany and operations in Chile, as well as its contributions to the development of Chilean astronomy, societal engagement and opportunities for local industry.

As part of the visit, they toured ESO’s Headquarters, including ESO’s Large Integration Hall, where components of ESO's Extremely Large Telescope are assembled, and other engineering facilities. Minister Lincolao also met with several ESO staff members, including Chilean staff working at the ESO Headquarters, before visiting the ESO Supernova Planetarium & Visitor Centre.

ESO Director General Xavier Barcons said: "Chile has the world’s most pristine dark skies for astronomy, which we are privileged to observe with our telescopes in the country, while contributing to the growth of Chilean astronomy and fostering technological innovation. We are very honoured to welcome Science Minister Lincolao to our headquarters in Germany to further strengthen our collaboration, for mutual benefit.”

ESO Annual Report 2025 now available

Wed, 08 Jul 2026 16:00:00 +0200

The ESO Annual Report 2025 is now available online, offering an engaging and high-level overview of ESO’s activities from the past year. The report was recently approved by the ESO Council at its June 2026 meeting.

Among the highlights are:

The latest progress in the construction of ESO’s Extremely Large Telescope (ELT), including the topping out ceremony for the ELT dome.
A major milestone for the Very Large Telescope (VLT) Interferometer and the GRAVITY+ project, as the VLT’s Unit Telescopes 1, 2 and 3 are equipped with laser guide star units.
The groundbreaking ceremony for CTAO-South, the southern array of the Cherenkov Telescope Array Observatory, now under construction at ESO’s Paranal site.
A selection of the fascinating scientific results published during 2025 using observations from ESO facilities.
ESO’s ongoing mission to protect dark and quiet skies, as well as how ESO contributes to and engages with society and our communities.
News from the La Silla Paranal Observatory and the Atacama Large Millimeter/submillimeter Array (ALMA), including forthcoming instruments and upgrades.
Technology development and R&D that keeps ESO facilities at the forefront of astronomy.

A “What is ESO?” introduction and “ESO’s year in numbers” at the start give an introduction to the organisation at a glance, and the report is illustrated throughout with beautiful astronomical images and photographs of the activities, observatory sites, and people.

This report is available to download for free and printed copies will be available in the ESOshop, free of charge with the exception of shipping costs, in the coming weeks.

ESO signs contract for next-generation deformable mirror for the VLT

Mon, 22 Jun 2026 16:00:00 +0200

Today, at ESO’s Headquarters in Garching, Germany, ESO and the AdOptica consortium signed a contract for the design and production of a new adaptive mirror, to be installed at our Very Large Telescope (VLT). AdOptica, a consortium made up of two Italian companies, Microgate and A.D.S. International, is a long-standing ESO industrial partner, working on projects such as the adaptive M4 mirror for ESO’s Extremely Large Telescope. ESO’s Director General Xavier Barcons, together with Roberto Biasi of Microgate and Daniele Gallieni of A.D.S. International were present for the signing.

ESO's VLT has four 8-metre Unit Telescopes but at present only one of them, UT4, has an adaptive optics facility, which includes a deformable mirror (the secondary, second in the path of light), as well as four lasers. Using either natural guide stars or artificial guide stars created by these lasers as references, we can measure how much the light from cosmic objects is deformed by Earth’s atmosphere. The adaptive or deformable mirror, which can change its shape very fast and with nanometric precision, then cancels out the deformation of the light in real time, giving us a much sharper view of the cosmos than would otherwise be possible. Because of its adaptive optics systems, together with highly demanded instruments, UT4 is one of the most oversubscribed telescopes on Earth.

Since November 2025, Unit Telescopes 1, 2 and 3 have each been equipped with a laser, as part of the GRAVITY+ upgrade. While these lasers are currently only used for observations with the VLT Interferometer, when all Unit Telescopes are observing together, they can also be used for stand-alone observations (with suitable instruments) — if the telescope they are projected from is equipped with a deformable mirror.

By procuring the production of a new deformable secondary mirror, which is planned for installation on UT3, ESO will expand the adaptive optics capabilities of the VLT with the help of AdOptica, who also built the deformable secondary mirror on UT4. This will reduce the pressure on UT4, since instruments equipped with a wavefront sensor can now also be installed on UT3 and benefit from state-of-the-art adaptive optics corrections. Ultimately, the improvements will allow more observations of cosmic objects in finer detail than is possible today.