Forty-five years after the Apollo and Luna missions returned the lunar samples, China's Chang’E-5 (CE-5) mission collected new samples from the mid-latitude region in the northeastern Oceanus Procellarum of the Moon. Our study shows that 95% of CE-5 lunar soil is distributed in the size of 1.40–9.35 μm, while 95% of the soil by mass is distributed in the size of 4.84–432.27 μm. The bulk density, true density, and specific surface area of CE-5 soil are 1.2387 g/cm3, 3.1952 g/cm3, and 0.56 m2/g, respectively. Fragments from CE-5 regolith are classified into igneous clasts (mostly basalt), agglutinate, and glass. A few breccias were also found. The minerals and compositions of CE-5 soils are consistent with mare basalts and can be classified as low-Ti/low-Al/low-K type with lower rare earth element (REE) contents than materials rich in potassium, rare earth element, and phosphorus (KREEP). CE-5 soils have high FeO and low Mg index, which could represent a new class of basalt.

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The Moon has a magmatic and thermal history that is distinct from that of the terrestrial planets1. Radioisotope dating of lunar samples suggests that most lunar basaltic magmatism ceased by around 2.9–2.8 billion years ago (Ga)2,3, although younger basalts between 3 Ga and 1 Ga have been suggested by crater-counting chronology, which has large uncertainties owing to the lack of returned samples for calibration4,5. Here we report a precise lead–lead age of 2,030 ± 4 million years ago for basalt clasts returned by the Chang’e-5 mission, and a 238U/204Pb ratio (µ value)6 of about 680 for a source that evolved through two stages of differentiation. This is the youngest crystallization age reported so far for lunar basalts by radiometric dating, extending the duration of lunar volcanism by approximately 800–900 million years. The µ value of the Chang’e-5 basalt mantle source is within the range of low-titanium and high-titanium basalts from Apollo sites (µ value of about 300–1,000), but notably lower than those of potassium, rare-earth elements and phosphorus (KREEP) and high-aluminium basalts7 (µ value of about 2,600–3,700), indicating that the Chang’e-5 basalts were produced by melting of a KREEP-poor source. This age provides a pivotal calibration point for crater-counting chronology in the inner Solar System and provides insight on the volcanic and thermal history of the Moon.

We report the surface exploration by the lunar rover Yutu that landed on the young lava flow in the northeastern part of the Mare Imbrium, which is the largest basin on the nearside of the Moon and is filled with several basalt units estimated to date from 3.5 to 2.0 Ga. The onboard lunar penetrating radar conducted a 114-m-long profile, which measured a thickness of ∼5 m of the lunar regolith layer and detected three underlying basalt units at depths of 195, 215, and 345 m. The radar measurements suggest underestimation of the global lunar regolith thickness by other methods and reveal a vast volume of the last volcano eruption. The in situ spectral reflectance and elemental analysis of the lunar soil at the landing site suggest that the young basalt could be derived from an ilmenite-rich mantle reservoir and then assimilated by 10-20% of the last residual melt of the lunar magma ocean.volcanic history | Imbrium basin | lunar rover Yutu | lunar penetrating radar | Chang'e-3 mission

Excesses of sulfur-36 in sodalite, a chlorine-rich mineral, in a calcium-and aluminum-rich inclusion from the Ningqiang carbonaceous chondrite linearly correlate with chorine͞sulfur ratios, providing direct evidence for the presence of short-lived chlorine-36 (with a half-life of 0.3 million years) in the early solar system. The best inferred ( 36 Cl͞ 35 Cl)o ratios of the sodalite are Ϸ5 ؋ 10 ؊6 . Different from other short-lived radionuclides, chlorine-36 was introduced into the inclusion by solid-gas reaction during secondary alteration. The alteration reaction probably took place at least 1.5 million years after the first formation of the inclusion, based on the correlated study of the 26 Al-26 Mg systems of the relict primary minerals and the alteration assemblages, from which we inferred an initial ratio of ( meteorite ͉ solar nebula ͉ sulfur isotopes ͉ magnesium isotopes ͉ chronometer S hort-lived, now extinct, radionuclides have been detected in primitive meteorites (1). They have been intensively studied and are still subjects of ongoing great interest for broad scientific audiences, because short-lived radionuclides may serve as the only available fine-scale chronometers to trace processes in the early solar system (1, 2), and their relative abundance can constrain the local galactic environment of solar system formation (3-6). However, the origin of short-lived radionuclides is a long-standing issue. One scenario holds that the short-lived radionuclides originated in stellar sources like supernovae (3, 7) or asymptotic giant branch stars (5, 6) in close proximity to the forming solar system. According to such a stellar origin, shortlived radionuclides were injected homogeneously in the solar nebula, hence they may be used as chronometers. This idea is supported by the measurement of U-Pb absolute ages of Caand Al-rich inclusions (CAIs) and chondrules with a Ϸ1-million year (My) resolution (8), which yields a time interval between formation of CAIs and chondrules similar to that inferred by many 26 Mg measurements, although a recent study reported that chondrule formation began contemporaneously with the formation of CAIs (9). On the other hand, the same short-lived radionuclides may be produced locally by intense irradiation of nebular materials by the proto-sun (10-12). The predictions of local irradiation models (4, 13) are compatible with the observed abundance of some nuclides (e.g., 10 Be, 26 Al, 41 Ca, and 53 Mn). According to local irradiation models, the systematically different initial ( 26 Al͞ 27 Al) o ratios between CAIs and chondrules are related to their different distances from the proto-sun, bearing no temporal significance.Chlorine-36 has a half-life of 0.3 My and decays to either 36 Ar (98.1%, ␤ Ϫ ) or 36 S (1.9%, and ␤ ϩ ) (14), hence it can be detected by measuring the excess of 36 Ar or 36 S. A previous study reported the excess of 36 Ar in matrix of the Efremovka carbonaceous chondrite (15), which was attributed to the decay of short-lived 36 Cl. In this study, we provide direc...

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The distribution of water in the Moon's interior carries key implications for the origin of the Moon 1 , the crystallisation of the lunar magma ocean 2 , and the duration of lunar volcanism 2 . The Chang'E-5 (CE5) mission returned the youngest mare basalt samples, dated at ca. 2.0 billion years ago 3 , from the northwestern Procellarum KREEP Terrane (PKT), providing a probe into the spatio-temporal evolution of lunar water. Here we report the water abundance and hydrogen isotope composition of apatite and ilmenite-hosted melt inclusions from CE5 basalts, from which we derived a maximum water abundance of 370 ± 30 g.g -1 and a δD value (-330 ± 160‰) for their parent magma. During eruption, hydrogen degassing led to an increase in the D/H ratio of the residual melts up to δD values of 300-900‰. Accounting for low degrees of mantle partial melting followed by extensive magma fractional crystallisation 4 , we estimate a maximum mantle water abundance of 2-6 g.g -1 , which are too low for water contents alone to account for generating the Moon's youngest basalts. Such modest water abundances for the lunar mantle are at the lower end of those estimated from mare basalts that erupted from ca. 4.0-2.8 Ga 5, 6 , suggesting the mantle source of CE5 basalts dried up by ca. 2.0 Ga through previous melt extraction from the PKT mantle during prolonged volcanic activity.Water abundance in the lunar mantle places strict constraints on high-temperature processes, including the Moon-forming giant impact 1 , the ensuing crystallisation of the lunar magma ocean 7 , and the longevity of volcanism on the Moon 2 . Based upon the analyses carried out since the Apollo era, the Moon was long thought to be an anhydrous body. Advances in in situ analytical techniques over the past decade have allowed analysis of water abundances at micro-scale in various lunar samples, including in olivine-and pyroxene-hosted melt inclusions in mare basalts [8][9][10][11][12] , apatite in mare basalts and highlands samples [13][14][15][16][17][18][19][20] , pyroclastic glass beads 21, 22 , and

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