Moon

30 April 2026

More than fifty years after the Apollo lunar missions, and with the success of the Artemis programme, the Moon has once again become the main objective of the major space powers. China aims to land its astronauts on the lunar surface by 2030, while NASA plans a new crewed Moon landing by 2028, in a competition that closely recalls the early days of the space age, when the Soviet Union and the United States faced each other. From those years, the iconic black-and-white images of Neil Armstrong during the Apollo 11 mission remain etched in collective memory: the first human being to set foot on the lunar surface, watched by millions of viewers around the world, glued to their television sets. It was one of the first great global media events, capable of uniting humanity in front of the same scene. For years, the most widely viewed image in the world would remain that small step by a man which in fact marked a giant leap for science and technology, projecting them into the future.

Beyond geopolitical dynamics, the fascination of the Moon, so close and at the same time so difficult to reach, continues to exert a profound attraction, capable of crossing and illuminating different eras and languages, from science to literature and the arts. An example is the trilogy 1Q84 by Haruki Murakami, one of the greatest successes of contemporary fiction of the past twenty years, in which two moons even appear as a metaphor for parallel worlds, the real and the fantastical, between which the protagonists move. It is precisely in this ability to imagine elsewhere, to multiply possibilities, that artistic creativity comes surprisingly close to the scientific outlook and to the intuition that leads from fundamental research to the development of technologies that find application in fields far removed from those in which they originated. In this context, the particle physics community is engaged in the development of technologies and projects designed for future lunar missions, as well as in the conception of new experiments to be installed directly on the surface of our satellite. Some of these solutions have already become reality: Medipix sensors, for example, have been included in the Artemis II mission, while instruments such as the MoonLIGHT laser retroreflectors are already operational on the Moon. Other technologies, currently under development, could reach it in the coming years.

Below we present the main projects in which the National Institute for Nuclear Physics is involved in this field.
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Astronaut bootprint on the lunar soil, photographed with a 70 mm camera on the lunar surface during the extravehicular activity (EVA) of the Apollo 11 mission on the Moon. Credit NASA

A close-up view of an astronaut's bootprint in the lunar soil, photographed with a 70mm lunar surface camera during the Apollo 11 extravehicular activity (EVA) on the moon. Credit NASA

Artemis I Flight Day 13: Orion, Earth, and Moon. Credit NASA

From CERN to space: Medipix sensors on board the Artemis II mission

On board the Orion spacecraft of the Artemis II mission there were six Timepix chips, advanced sensors for particle and radiation detection developed at CERN within the framework of the international Medipix 2 collaboration, in which the National Institute for Nuclear Physics and research groups from the Universities of Cagliari, Naples and Pisa also participated. During the approximately ten days of the mission, these devices monitored in real time the characteristics and level of radiation inside the spacecraft. This is a crucial measurement: outside the protection of the Earth’s geomagnetic field, astronauts are exposed to significantly higher levels of radiation than those typical of low Earth orbit. The Timepix chips are part of the HERA system developed by NASA and contribute to the assessment of exposure of both the crew and onboard electronics due to galactic cosmic rays which, by striking the spacecraft, generate charged fragments, neutrons, pions, muons, electrons and positrons.

This technology derives from hybrid pixel detectors used in experiments at the Large Hadron Collider particle accelerator at CERN, and is able to distinguish different types of radiation thanks to the analysis of the tracks left by particles in the sensors, in a manner analogous to what occurs in the large detectors of experiments such as ATLAS, CMS or ALICE, from which the first developments of hybrid detectors originated. Devices based on the same technology are also used in the medical field, particularly in diagnostic imaging. Evolving from instruments developed since the late 1990s, these sensors form the basis of next-generation imaging systems capable of providing more precise and detailed images. In the future, these technologies may contribute to significant improvements, for example in X-ray diagnostics, for which applications such as a portable photon-counting CT scanner capable of producing colour imaging have been developed. In addition, a monitoring system for hadrontherapy treatments is under development.

The Timepix chip. Credit CERN.

A new generation of laser retroreflectors: the MoonLIGHT project

Starting in 1969, with the Apollo 11, Apollo 14 and Apollo 15 missions, together with the Soviet rovers Lunokhod 1 and Lunokhod 2, special devices called laser retroreflectors (LRA – Laser Retroreflector Array) were installed on the lunar surface. These instruments, consisting of arrays of corner cube retroreflectors (CCR – Corner Cube Retroreflector), have the property of reflecting light exactly in the direction from which it originates, that is, back towards laser stations on Earth. Thanks to these devices it is possible to use a technique called Lunar Laser Ranging (LLR), which makes it possible to measure with extreme precision the distance between the Earth and the Moon. The method consists of sending short laser pulses from Earth towards the lunar retroreflectors and measuring the time taken by the light to complete the round trip. Over the years, these measurements have made it possible to obtain highly significant scientific results: very accurate tests of general relativity, information on the internal structure of the Moon, precise data on its motion (ephemerides), on the position of the reflectors on the lunar surface and of the stations on Earth, as well as fundamental parameters for describing the orientation of our planet. Over the past 55 years, the performance of terrestrial laser stations has improved considerably. However, the overall precision of the measurements is limited by the reflectors installed during the Apollo and Lunokhod missions. This limitation is due to so-called lunar librations, apparent oscillations of the Moon caused by the shape and inclination of its orbit, which introduce an uncertainty greater than that achievable today with laser technologies on Earth.

To overcome this limitation, the MoonLIGHT (Moon Laser Instrumentation for General Relativity High-accuracy Tests) project has been developed at the INFN National Laboratories of Frascati (LNF) of the National Institute for Nuclear Physics. The aim is to create a new generation of lunar retroreflectors designed not to be affected by librations. The heart of the instrument is a single large corner cube retroreflector (100 mm), much more precise than previous configurations. This technology has been developed through a collaboration between the INFN National Laboratories of Frascati, the University of Maryland, the Matera Laser Ranging Observatory of the Italian Space Agency (ASI) and the University of Padua. In 2025 the first next-generation reflector was successfully installed on the Moon thanks to a NASA mission. A second reflector will be launched by the end of 2026 with a joint NASA–ESA mission.

The operation of MoonLIGHT requires very accurate pointing towards the Earth: its field of view is in fact limited to a cone with a maximum opening of 15°, while lunar librations can reach up to about 10°. To ensure this precision, INFN-LNF has developed a dedicated pointing system, the MoonLIGHT Pointing Actuator (MPAc), subsequently selected by the European Space Agency for development. MPAc is designed to orient the reflector with great precision through two perpendicular rotational movements, operating in extreme conditions of vacuum and temperature on the lunar surface. The MoonLIGHT/MPAc system was completed and qualified in 2023, and then accepted by ESA (European Space Agency), NASA and the company Intuitive Machines. Launch is planned within the Commercial Lunar Payload Services (CLPS) programme, with destination the lunar site Reiner Gamma. After some postponements related to the programme’s initial missions, launch is currently scheduled for 2026. The instrument is already ready and stored in Houston, awaiting launch.

MoonLIGHT: single solid retroreflector for lunar laser measurements. Credit INFN

In parallel with the development of MoonLIGHT/MPAc, miniaturised laser retroreflector technology landed on Mars in 2018. On board NASA’s InSight lander was LaRRI (Laser Retro-Reflector for InSight), a micro laser reflector developed by the INFN National Laboratories of Frascati with the support of the Italian Space Agency (ASI). Another similar one (LaRA, Laser Retroreflector Array) was deployed on NASA’s Perseverance rover, which has been searching for signs of life on Mars since 2021. The miniaturised technology of LaRRI/LaRA has also been applied to the Chinese Chang’e 6 mission of the China National Space Administration (CNSA), which successfully landed on the far side of the Moon.

A specialised space laboratory at the National Laboratories of Frascati

Also thanks to these experiences, and to the development of LRAs for Galileo 2nd Generation (G2G) and COSMO-SkyMed Second Generation (CSG), about twenty years ago the SCF_Lab was established at the National Laboratories of Frascati, a specialised research and industrial laboratory dedicated to the design, construction, characterisation and space qualification of laser retroreflectors installed on artificial satellites and celestial bodies for their precise positioning through laser tracking techniques. The celestial bodies of interest include the Moon, Mars, other moons, asteroids and comets. SCF_Lab is a laboratory in partnership with ESA and the Italian Space Agency (ASI) and collaborates internationally with the American (NASA), Chinese (CNSA) and Indian (ISRO) agencies on missions and studies concerning the Earth and the rest of the Solar System.

Multimessenger astronomy: X-ray sensors on the lunar surface

Following the detection of gravitational waves and their electromagnetic counterparts, and with the consolidation of neutrino astronomy, the study of the universe has entered the era of multimessenger astronomy: an approach that combines different types of information, such as light, particles and gravitational signals, to observe cosmic phenomena in their complexity and identify their origins. In this new scenario, it becomes crucial to have instruments capable of continuously monitoring the sky. It is in this scientific context that the LEM-X (Lunar Electromagnetic Monitor in X-rays) project was born, for the development of “soft” X-ray sensors (X-rays characterised by lower energies and therefore longer wavelengths than so-called “hard” X-rays), for continuous monitoring of the sky from the lunar surface. The project aims to fill an important observational gap: wide-field coverage in the “soft” X-ray band, still poorly explored by orbiting missions with extensive continuous monitoring capabilities. LEM-X uses technologies developed within the eXTP mission, a satellite mission of the Chinese Academy of Sciences (CAS) aimed at studying black holes of all masses observed so far in the universe and neutron stars with different magnetic field strengths. In particular, LEM-X is based on technologies used in the Wide Field Monitor (WFM) and develops them into a modular structure: a “dome” composed of numerous identical modules, each oriented in a different direction. In this way, the instrument will be able to cover half the sky simultaneously and, thanks to the rotation of the Moon, the entire celestial sphere can be observed over time. Each module of the system integrates large-area Silicon Drift Detectors (SDD), developed in Italy through a collaboration between INFN (with the Trieste sections and the TIFPA in Trento), INAF (National Institute for Astrophysics), ASI and FBK (Bruno Kessler Foundation).

Earth from the Moon. credit NASA

Esperimento ALICE- Credit CERN

LEM-X has its origins in high-energy physics, in particular in technologies developed for the ALICE detector of the LHC accelerator. In particular, these detectors were initially designed in Trieste, in collaboration with Canberra (now Mirion Technologies), for layers 3 and 4 of the Inner Tracking System (ITS) of the ALICE detector and were used to track charged particles in the outer layers of the ITS, with high spatial precision. These technologies, born in fundamental research in particle physics, have subsequently found an application in X-ray spectroscopy and imaging. The basic module of LEM-X is currently under development within the Italian collaboration that participated in the eXTP mission, part of a broader consortium involving several European countries. Although the LEM-X project has not yet been formally discussed within the wider collaboration, it represents a natural evolution of the technologies under development and could in the future involve the same international partners

Detecting gravitational waves from the Moon: the LGWA project

The Lunar Gravitational-wave Antenna (LGWA) is a highly innovative project that aims to detect gravitational waves directly from the Moon. Selected in 2023 by ESA within the Reserve Pool of Science Activities for the Moon, LGWA received the highest evaluation among all the proposals submitted. The scientific objective is ambitious: to observe signals from compact binary systems, from white dwarfs in our galaxy to massive black holes at cosmological distances, as well as to study the internal structure of the Moon and understand the mechanisms underlying its seismic phenomena. Following this recognition, the Italian Space Agency funded the preparatory studies of Italian-led projects selected by ESA. LGWA is developed by a consortium led by the Gran Sasso Science Institute, involving the University of Camerino, the National Institute for Astrophysics, the National Institute of Geophysics and Volcanology, and the National Institute for Nuclear Physics. The idea of using the Moon itself as a detector of gravitational waves dates back to the 1970s, thanks to the work of the American physicist Joseph Weber, who contributed to the development of the Lunar Surface Gravimeter installed during the Apollo 17 mission. Although that experiment was unsuccessful due to a technical problem, today LGWA builds on that intuition with advanced technologies, with the aim of opening new perspectives in astrophysics and planetary sciences. Currently, the activities, funded by ASI, are focused on the technological development of the lunar payload, and activities relating to the characterisation of the lunar soil have begun, through modelling of the propagation of seismic waves, as well as on the scientific analysis of gravitational signals. The funding covers the first two years of preparatory studies, with the possibility of extending activities beyond 2027.

a cura di Ufficio Comunicazione INFN – COMUNICAZIONE ISTITUZIONALE E MEDIA