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Over 60 years of spacecraft exploration has revealed that the Earth’s Moon is characterized by a lunar crust 1 dominated by the mineral plagioclase, overlying a more mafic (richer in iron and magnesium) mantle of uncertain composition. Both crust and mantle formed during the earliest stages of lunar evolution when late-stage accretional energy caused a molten rock (magma) ocean, flotation of the light plagioclase, sinking of the denser iron-rich minerals, such as olivine and pyroxene, and eventually solidification 2 . Very large impact craters can potentially penetrate through the crust and sample the lunar mantle. The largest of these craters is the approximately 2,500-kilometre-diameter South Pole-Aitken (SPA) basin 3 on the lunar far side. Evidence obtained from orbiting spacecraft shows that the floor of the SPA basin is rich in mafic minerals 4 , but their mantle origin is controversial and their in situ geologic settings are poorly known. China’s Chang’E-4 lunar far-side lander recently touched down in the Von Kármán crater 5 , 6 to explore the floor of the huge SPA basin and deployed its rover, Yutu-2. Here we report on the initial spectral observations of the Visible and Near Infrared Spectrometer (VNIS) 7 onboard Yutu-2, which we interpret to represent the presence of low-calcium (ortho)pyroxene and olivine, materials that may originate from the lunar mantle. Geological context 6 suggests that these materials were excavated from below the SPA floor by the nearby 72-km-diameter Finsen impact crater event, and transported to the landing site. Continued exploration by Yutu-2 will target these materials on the floor of the Von Kármán crater to understand their geologic context, origin and abundance, and to assess the possibility of sample-return scenarios. Initial spectral observations by China’s Chang’E-4 far-side lunar rover suggest the presence of materials that may originate from the Moon’s mantle.

A new era of lunar exploration has begun bringing immense opportunities for science as well. It has been proposed to deploy a new generation of observatories on the lunar surface for deep studies of our Universe. This includes radio antennas, which would be protected on the far side of the Moon from terrestrial radio interference, and gravitational-wave (GW) detectors, which would profit from the extremely low level of seismic disturbances on the Moon. In recent years, novel concepts have been proposed for lunar GW detectors based on long-baseline laser interferometry or on compact sensors measuring the lunar surface vibrations caused by GWs. In this article, we review the concepts and science opportunities for such instruments on the Moon. In addition to promising breakthrough discoveries in astrophysics and cosmology, lunar GW detectors would also be formidable probes of the lunar internal structure and improve our understanding of the lunar geophysical environment.

Yutu-2 rover conducted an exciting expedition on the 41st lunar day to investigate a fin-shaped rock at Longji site (45.44°S, 177.56°E) by extending its locomotion margin on perilous peaks. The varied locomotion encountered, especially multi-form wheel slippage, during the journey to the target rock, established unique conditions for a fin-grained lunar regolith analysis regarding bearing, shear and lateral properties based on terramechanics. Here, we show a tri-aspect characterization of lunar regolith and infer the rock’s origin using a digital twin. We estimate internal friction angle within 21.5°−42.0° and associated cohesion of 520-3154 Pa in the Chang’E-4 operational site. These findings suggest shear characteristics similar to Apollo 12 mission samples but notably higher cohesion compared to regolith investigated on most nearside lunar missions. We estimate external friction angle in lateral properties to be within 8.3°−16.5°, which fills the gaps of the lateral property estimation of the lunar farside regolith and serves as a foundational parameter for subsequent engineering verifications. Our in-situ spectral investigations of the target rock unveil its composition of iron/magnesium-rich low-calcium pyroxene, linking it to the Zhinyu crater (45.34°S, 176.15°E) ejecta. Our results indicate that the combination of in-situ measurements with robotics technology in planetary exploration reveal the possibility of additional source regions contributing to the local materials at the Chang’E-4 site, implying a more complicated geological history in the vicinity. Digital twins can be used to support planetary operations and analysis. Here, the authors show tri-aspect characterization of lunar far side regolith and investigate the origin of a fin-shaped rock via digital twin of Yutu-2 rover.

China’s Chang’e-4 (CE-4) mission is the first human lander/rover mission on the far side of the Moon. Its probe is composed of a lander, rover, and the Queqiao relay satellite. Queqiao was successfully launched on May 21, 2018, and entered the halo orbit of the L2 point on June 14, becoming the first satellite connecting the Earth and the Moon’s far side. The lander carrying Yutu-2 was successfully launched on December 8, 2018, and landed in the Von Kármán crater (45.5° S, 177.6° E) at 10:26 (UTC+8) on January 3, 2019. The CE-4 probe carried nine science instruments. Four instruments are on the lander: a landing camera (LCAM), a terrain camera (TCAM), a low-frequency radio spectrometer (LFRS), and a lunar lander neutrons and dosimetry (LND) provided by Germany. Four instruments are on the rover: a panoramic camera (PCAM), a visible and near-infrared imaging spectrometer (VNIS), a lunar penetrating radar (LPR), and an advanced small analyzer for neutrals (ASAN) provided by Sweden. The instrument on the relay satellite is the Netherlands-China Low-Frequency Explorer (NCLE). The scientific objectives of the CE-4 mission include (1) performing low-frequency radio-astronomical observations; (2) investigating the geomorphology, mineral compositions and shallow subsurface structure of the landing and roving sites; and (3) detecting the Earth-Moon space environment at the lunar far side. As of February 1, 2020, CE-4 has completed 14 lunar days of scientific exploration after one year of operation. The components, fight, scientific objectives and investigation of CE-4 are introduced in this paper. We also describe the accessibility of the initial archived science data and their preliminary analysis results.

Chang’E 4 is the first mission to the far side of the Moon and consists of a lander, a rover, and a relay spacecraft. Lander and rover were launched at 18:23 UTC on December 7, 2018 and landed in the von Kármán crater at 02:26 UTC on January 3, 2019. Here we describe the Lunar Lander Neutron & Dosimetry experiment (LND) which is part of the Chang’E 4 Lander scientific payload. Its chief scientific goal is to obtain first active dosimetric measurements on the surface of the Moon. LND also provides observations of fast neutrons which are a result of the interaction of high-energy particle radiation with the lunar regolith and of their thermalized counterpart, thermal neutrons, which are a sensitive indicator of subsurface water content.

To systematically assess the surface radiation environment on the lunar far side and its implications for crewed lunar missions, this study utilizes data from the Lunar Lander Neutrons and Dosimetry Experiment (LND) onboard the Chang'e-4 mission. We analyzed 44 effective lunar daytime observation datasets collected from January 2019 to March 2024, aiming to uncover the long-term evolution of the lunar surface radiation dose and its correlation with solar activity. The structural composition of the LND detector and its multi-channel particle identification and energy spectrum measurement principles are described in detail. To address gaps in the data, historical radiation dose series were reconstructed by using linear and multiple regression methods. The F10.7 solar radio flux index was introduced as a physical parameter to gauge solar activity intensity, and its dynamic relationship with the lunar surface radiation dose was systematically analyzed. The study found a significant negative correlation between the total lunar surface radiation dose and the F10.7 index, with an average equivalent dose rate of 13.95 μGy/h, and approximately 22% of the total radiation dose attributed to neutral particles, a proportion that remains stable across different solar cycles. Further analysis of LND measurements during solar particle events (SPEs) indicates that SPE outbreaks cause the radiation dose rate on the lunar surface to spike by 10 to 100 times, followed by an exponential decay, mainly reflecting the dynamics of secondary neutron moderation. This research not only enriches the observational data of the lunar far side's radiation environment but also provides critical scientific support for the design of radiation protection and real-time warning systems for future crewed lunar missions.

Due to the tidal locking, the far side of the Moon is permanently turned away from the Earth. Its polarization characteristics are still poorly understood, limiting our knowledge of material composition and evolution. Previous studies have indicated a correlation between the distributions of degree of polarization (DOP) and the iron oxide (FeO) abundance on the Moon, suggesting a new approach to infer the polarization characteristics of the lunar far side from FeO abundance distribution. Three critical issues have been analyzed: (1) A linear regression model between DOP and FeO abundance is proposed based on control points from ground-based near side polarization images. (2) The DOP distribution of the lunar far side is estimated, based on the established model, revealing significant hemispheric differences in polarization characteristics. (3) The relationship between DOP and lunar phase angle is examined, with the fitted values demonstrating strong agreement with the observations in both magnitude and variation trend. These insights offer valuable guidance for comprehensive polarimetric studies of the Moon.

This short paper explores the century-long journey of searching for extraterrestrial intelligence (SETI) with a focus on the radiowave spectrum. Beginning with early experiments by David Todd and Charles Jenkins, who attempted interplanetary communication using radio technology, it traces the historical development of SETI. The paper discusses significant milestones, such as Project OZMA in 1961 and the transition to modern searches, particularly the Breakthrough Listen project, which represents the most comprehensive effort in SETI history. The vastness of the Universe, the potential for life in various planetary systems and the challenges of differentiating between basic life and intelligent life are highlighted. The discussion includes the concept of technosignatures—signals indicative of advanced technology—and the advancements in telescope technology like the Square Kilometre Array Observatory (SKAO) that enhance SETI capabilities. Recent developments are also addressed, such as an intriguing signal detected in 2020 and the future of SETI is envisioned, including the possibility of building a radio telescope on the far side of the Moon to escape interference from human technosignatures as humans continue to expand into space.