Recently, I participated in the 18th International Olympiad on Astronomy and Astrophysics (IOAA) 2025 in Mumbai as team leader for Algeria. Held from August 11-21, it marked Algeria’s first participation. The event brought together 64 countries and nearly 300 contestants.Participation in such an excellence-based event transcends the mere pursuit of medals. Winning distinctions holds significance for both participating countries and the contestants, boosting national education systems and inspiring the next generation to take an interest in STEM subjects. This Olympiad is arguably the most multidisciplinary of all science Olympiads as the required skills span physics, astrophysics, cosmology, mathematics and connected disciplines like astronautics and data analysis. High achievers often secure significant opportunities for their post-secondary education, opening doors to prestigious universities and potential careers as leading scientists, astronomers, or engineers.The opening ceremony. Photo: By arrangementThe event began on August 11 with an opening ceremony in Mumbai, featuring a special address by Indian Prime Minister Narendra Modi. It included cultural performances and drew representatives from all participating countries, marking the largest IOAA to date with 64 nations. This set a formal tone for the competition, emphasising its international scope.A rigorous competition, not for fragile mindsThe competition featured rigorously developed problems spanning astrophysics and cosmology, needing a healthy dose of Math skills, all of them reviewed by the delegates to ensure accuracy and fairness. A landmark innovation was the historic introduction of locally made 14 radio telescopes in the practical exam, bringing radio astronomy to the Olympiad for the first time in its history. The delegates in session. Photo: By arrangementOver three days, students tackled theoretical, practical, and observational exams. A planetarium session was even required to compensate for the inclement weather in Bombay during that time of year, which prevented the observational exam from being conducted under the night sky. This was followed by the moderation phase, during which gradings were compared before the final list of medalists was established.The radiotelescopes room. Photo: By arrangementContestants in action. Photo: By arrangementA resolution against IsraelLike in every edition of IOAA, an international board meeting (IBM) is programmed during the Olympiads allowing delegates to discuss various issues and proposals for improvement. An agenda was circulated in advance, allowing the delegates to submit observations and additional propositions. The various items took one extended morning to discuss. One pivotal item tackled at the end of the meeting stemmed from a petition signed by over 530 scientists (including astrophysicists and mathematicians) worldwide, urging IOAA to take a moral stand against Israel’s participation amid the ongoing genocide in Gaza. This strong-worded letter listed three areas :The Severe Humanitarian Crisis that Israel’s criminal actions have created causing massive civilian casualties, widespread destruction of educational infrastructure, and the deliberate creation of a famine by obstructing humanitarian aid as recognized by the UN agencies.Suppression of Academic Participation as it actively prevents Palestinian students, particularly from Gaza, from participating in the international event, thereby denying them their academic rights.Violations of International Law and ICJ Rulings: All these actions are in direct violation of international law, specifically the Genocide Convention, and defy the legally binding orders of the International Court of Justice (ICJ) regarding humanitarian access and the legality of the occupation.Exodus of the Palestinian people following the recent Israeli offensive on Gaza city. Photo: By arrangementThe debate was vigorous, allowing all the viewpoints to be presented – yet rejecting double standards compared to actions against Russia and Belarus post-Ukraine invasion. The resolution was passed overwhelmingly (save three votes against) on August 18: Israel is excluded from future team competitions, but Israeli students may participate as individuals under the IOAA flag, without national identifiers.To cut short some speculations which have circulated since, none of the Indian scientists participating at IOAA were among the signatories of the petition. Furthermore, the conduct of the IBM business session is strictly the prerogative of the International Board and was carried out according to the IOAA statutes. An item on the agenda prepared by the General Secretariat and subsequently ratified by all delegates, cannot be set aside. On the contrary, failing to bring the issue for discussion after it had been placed on the agenda would have caused considerable damage to the meeting’s image. This, in turn, would have reflected poorly on the host country as being impervious to the rights and duties of the delegates. Ultimately, the delegates at the IBM bear the responsibility for all decisions taken that day.This protest is part of the general trend to isolate Israel on the political, cultural and scientific scenes for its genocidal actions. Furthermore, the International Olympiad in Informatics made a similar decision last year, which was confirmed again in their meeting this year. We believe that this balanced yet principled decision taken by IOAA, reinforces its ethical framework while preserving access for young talents worldwide.Closing ceremonyThe event concluded on August 21 at the Nita Mukesh Ambani Cultural Centre (NMACC) in Mumbai. The ceremony included a medal presentation for top performers in theoretical and practical categories. Alongside were cultural performances, such as a young pianist’s recital and choreography, as well as addresses from top Indian scientists and administrators. It concluded a successful event managed with expertise, impressive organisational skill and cultural warmth. Jamal Mimouni is an astrophysicist at the department of physics, University of Constantine 1 & CERIST, Algeria.