How Cosmic Dust, Solar Wind, and Impacts Quietly Reshape the Surfaces of the Moon, Mars
Planetary surfaces across the Solar System may seem calm and unchanged, but at microscopic scales, they are constantly changing. Every day, tiny dust particles strike the Moon and other airless bodies at speeds over tens of kilometers per second. Simultaneously, streams of charged particles from the Sun, known as the solar wind, continuously bombard exposed materials. Over millions of years, these subtle but persistent processes gradually change the chemistry, structure, and appearance of planetary materials.
Recent studies examining lunar samples brought back by China’s Chang’e missions, along with laboratory simulations and meteorite analyses, are revealing how these processes reshape planetary surfaces. By studying microscopic mineral changes, scientists are beginning to reconstruct how space weathering interact to transform the Moon, Mars, and the small bodies that formed the early Solar System.
Space weathering is one of the key processes modifying airless planetary bodies. Solar wind particles and micrometeorite impacts constantly interact with surface materials, creating structural damage layers and changing the optical properties of planetary soils.
Studies of lunar samples from the Chang’e-5 and Chang’e-6 missions show that individual mineral grains record long-term exposure to solar wind irradiation. By measuring radiation-damaged rims and particle tracks within these grains, researchers can estimate how long the grains have been on the lunar surface and how solar wind exposure varies across different regions of the Moon [1].
Micrometeorite impacts also play a significant role in lunar surface evolution. Detailed microscopic analysis of Chang’e-5 samples revealed unusual titanium-oxide minerals forming along the rims of tiny impact craters. These minerals probably formed when high-velocity dust particles melted and vaporized lunar materials during impact events. The discovery of these previously unrecognized Ti-oxide phases highlights how even microscopic impacts can generate new minerals and slowly modify the chemistry and optical properties of lunar regolith [2].
At a broader scale, recent observations show that meteoroid impacts at sub-meter sizes occur at similar rates across both the near and far sides of the Moon, indicating that this continuous “background” bombardment is spatially uniform and contributes consistently to surface modification over time [3].
At microscopic levels, minerals preserve detailed records of planetary processes. Nanophase iron, a key product of space weathering, was previously thought to form mainly through the reduction of lunar surface materials during impact events. New findings from the team, however, reveal an additional pathway: some nanophase iron originates directly from the residues of impacting bodies and is retained within the lunar soil after impact. This indicates that space weathering products can partly derive from external materials. These nanoparticles also influence how lunar soils absorb and scatter light, shaping how scientists interpret remote sensing observations of planetary surfaces [4].
Solar wind irradiation can also induce chemical changes in planetary minerals. Laboratory experiments simulating solar wind irradiation showed that hydrogen ions can remove sulfur from the mineral troilite (FeS), creating altered surface layers and measurable sulfur loss over time. This process helps explain sulfur depletion observed on the surfaces of the Moon and some asteroids [5].
Meteorites also provide a valuable record of planetary history. Analyses of iron-nickel metal in ordinary chondrites reveal how shock waves from asteroid collisions reshape metallic microstructures. Features like Neumann bands and different types of plessite reflect the temperatures and pressures experienced during ancient impact events, allowing scientists to reconstruct the thermal and impact history of asteroid parent bodies [6], [7].
Meanwhile, research on Martian meteorites suggests that some areas of Mars experienced relatively low-impact forces. Analyses of feldspar grains show that most recorded shock pressures are within ranges that could allow geological—and possibly biological—signatures to survive [8].
Together, these studies demonstrate that planetary surfaces are dynamic systems shaped by ongoing microscopic processes. Solar wind irradiation, micrometeorite impacts, and ancient impacts progressively change minerals, redistribute chemical elements, and influence how planetary surfaces interact with sunlight and radiation.
Understanding these processes helps scientists better interpret remote sensing observations of the Moon, Mars, and asteroids. Mineral records preserved in meteorites and returned samples also offer a timeline of the Solar System’s impact history and radiation environment.
Finally, identifying regions that experienced relatively mild impacts, such as parts of Mars, can guide future exploration efforts in the search for preserved geological or biological signatures. By studying the smallest mineral, chemical, structural, and optical property changes, scientists are uncovering the quiet forces that have shaped planetary surfaces for billions of years.
*Notes: This article provides research teasers for each reference to showcase the novelties
[1] R. Liu et al., “Million-year solar wind irradiation recorded in Chang’E-5 and Chang’E-6 samples,” Nature Communications, vol. 16, 2025, doi: 10.1038/s41467-025-64239-8
[2] X. Zeng et al., “Unusual Ti minerals on the Moon produced by space weathering,” Nature Astronomy, vol. 8, pp. 732–738, 2024, doi: 10.1038/s41550-024-02229-4
[3] R. Liu et al., “Meteoroid flux at sub-meter scales is homogeneous across the lunar nearside and farside,” Communications Earth & Environment, 2026, doi: 10.1038/s43247-026-03270-z
[4] X. Zeng et al., “Exotic nanophase iron as a new agent for space weathering on the Moon,” The Astrophysical Journal Letters, vol. 983, 2025, doi: 10.3847/2041-8213/adbf88
[5] C. Sun et al., “Revealing the loss of sulfur on troilite under simulated solar wind H⁺ irradiation,” Astronomy & Astrophysics, vol. 702, A81, 2025, doi: 10.1051/0004-6361/202555234
[6] Y. Luo et al., “EBSD analysis of iron-nickel metal in L type ordinary chondrites: 1. The microstructural shock signatures,” Journal of Geophysical Research: Planets, vol. 129, 2024, doi: 10.1029/2023JE007938
[7] Y. Luo et al., “EBSD analysis of iron-nickel metal in L type ordinary chondrites: 2. Formation of net, acicular, duplex, and pearlitic plessite,” Journal of Geophysical Research: Planets, vol. 129, 2024, doi: 10.1029/2023JE007940
[8] X. Zeng and W. Yu, “The low-intensity impact environment of Mars recorded by the infrared spectra of feldspar,” Acta Mineralogica Sinica, vol. 45, no. 6, 2025, doi: 10.3724/j.1000-4734.2025.45.112
From Natural Products to Drug Candidates: A Two-Way Research Model for Future Therapies in Cardiovascular, Arthritis, and Cancer Diseases
Over the past two decades, under the leadership of Professor Yi-Zhun Zhu, researchers at the Macau University of Science and Technology have been focusing on a distinctive bidirectional research model for small molecule drug development. This integrated strategy combines two complementary approaches: “from bioactive natural compounds to novel target identification” and “from novel therapeutic target to new small-molecule development.” Moving beyond conventional linear drug discovery processes, this framework facilitates bidirectional innovation, advancing both fundamental researches and translational applications.
Drug discovery can be conceptualized as an exploration on a vast island. Traditional approaches often follow a single linear route toward therapeutic breakthroughs, namely, the treasure. In contrast, the bidirectional model offers greater flexibility. Investigations may begin with a “coin” already in hand—such as Leonurine (SCM-198), S-Propargyl-Cysteine (SPRC), the natural compounds functioning as a valuable starting point. By studying that coin closely, researchers uncover clues about its origins, which in turn point them toward new biological targets and therapeutic directions, including NOX4, SMYD3, JMJD3, HDAC6 and so on. Alternatively, the journey begins the other way around, with a “map” in hand—a promising biological mechanism such as HDAC6/MyD88/NF-κB signaling pathway or STAT3-NAV2 axis in arthritis, serving as a guide for rational drug design. In both cases, the two pathways converge, leading to synergistic advances in drug discovery.
This strategy has yielded significant milestones, including the industrial translation of first-in-class therapeutics, and continues to drive progress across multiple therapeutic areas. In particular, the model has guided three major research trajectories: starting with leonurine, a natural product with traditional cardiovascular applications that has been advanced into modern drug development; extending into SPRC, a synthetically designed modulator of hydrogen sulfide; and progressing to epigenetic drug discovery through SMYD3 inhibition, a path with implications for vascular aging and oncology. Collectively, these directions illustrate how atural product-derived insights and target-driven design can converge within a single framework to shape the next era of medicine.
From Small molecule-to-Target: Leonurine
The journey along the “small molecule-to-target” pathway began with leonurine, a compound derived from Leonurus japonicus, a plant used in traditional medicine for cardiovascular health and gynecological diseases. What makes Leonurine significant is not only its herbal origins but also its development into a scientifically validated compound with cardioprotective effects, anti-inflammatory properties, pro-angiogenic effects following cardiac injury, and potential applications beyond cardiovascular disease which accounts for 17.9 million annual deaths globally [1] [2,3]. Beyond cardiovascular applications, it has demonstrated efficacy in mitigating endometriosis via modulation of estrogen-mediated immune dysfunction [4], as well as anti-atherosclerotic and hepatoprotective activities [5,6]. The team has also advanced Leonurine into novel formulations, the team developed a sustained-release leonurine formulation using PLGA microspheres encapsulating drug nanocrystals (Leo-nano@MP), which significantly improved lipid metabolism and reduced dosing frequency via subcutaneous administration in a hyperlipidemic rat model, demonstrating high drug loading, prolonged release, and good biocompatibility [7].
This pathway exemplifies how a single bioactive natural product can unravel novel mechanisms and open new therapeutic avenues. Leonurine thus serves as a prototype for transforming traditional herbal compounds into first-in-class therapeutics with validated mechanisms of action.
The translational development of Leonurine is supported by multiple patents from Professor Zhu’s group, covering pharmaceutical formulations and delivery technologies. For example, these include nanoliposome and microsphere systems that enhance bioavailability and enable controlled release, broadening the therapeutic window for cardiovascular and inflammatory diseases. Their patents also highlight leonurine’s role in modulating lipid metabolism, PPARγ pathways, and its use in treating liver disease and inflammation-related disorders. Collectively, these innovations elevate Leonurine from a traditional herbal compound into a modern, patent-protected therapeutic entity with substantial clinical potential.
From Small molecule-to-Target: another example, SPRC and CSE
If Leonurine represents the journey from monomer to target, S-Propargyl-Cysteine (SPRC) illustrates the complementary path—from target to molecule. Here, the therapeutic target is cystathionine Gamma Lyase (CSE), an enzyme that produces the signaling molecule hydrogen sulfide (H₂S) from L-cysteine. SPRC acts as a donor of endogenous H₂S, an endogenous gasotransmitter known for its profound effects on vascular health, inflammation, and longevity. Based on this mechanistic insight, SPRC was designed as a synthetic amino acid derivative that modulates H₂S levels.
Based on Professor Zhu’s studies, SPRC has demonstrated wide-ranging benefits: regulating immune responses, protecting neurons after stroke, and promoting angiogenesis [8,9]. In rheumatoid arthritis (RA), which affects over 18 million people globally [10], SPRC has been shown to rebalance immune cells by inhibiting the JAK/STAT pathway, reducing inflammation and slowing joint damage [11]. Beyond exploring the pharmacological efficacy of SPRC, the team have also engineered SPRC-based nanocarriers and hybrid molecules for precision therapies against RA,
This small molecule-to-target pathway highlights how identifying a novel biological mechanism—in this case, CSE as the target of SPRC—can inspire the rational design of first-in-class therapeutic candidates with translational potential.
Patents filed by Professor Zhu and his team surrounding SPRC and related signaling pathways demonstrate the translational depth of this pathway by engineering innovative drug delivery platforms. Microsphere and mesoporous silica formulations enhance the stability and sustained release of SPRC, improving its therapeutic precision in diseases such as rheumatoid arthritis and ischemic injury. Additionally, their patents on endogenous H₂S donors for RA treatment underscore the progression from mechanistic insight to tangible therapeutic inventions. These intellectual property advances ensure SPRC’s positioning not just as a promising molecule, but as a scalable and clinically adaptable treatment strategy.
Target-to-Molecule: SMYD3 and Epigenetic Regulation
Extending the target-driven approach further, the researchers turned their attention to the epigenetic regulator SMYD3, a histone methyltransferase linked to vascular aging, cellular remodeling, and cancer progression. Unlike Leonurine’s herbal origins, SMYD3 inhibition begins firmly at the target level, with the goal of designing molecules that disrupt pathogenic gene regulation.
Professor Zhu’s research team showed that, through high-throughput screening and structure-based drug design, small molecules such as ZYZ384 were identified to reduce cancer cell proliferation by lowering H3K4 trimethylation on oncogenic promoters. In models of hepatocellular carcinoma, SMYD3 inhibition suppressed tumor growth, offering a new precision epigenetic strategy against cancer [14]. Beyond oncology, targeting SMYD3 also addresses vascular senescence, the progressive aging of blood vessels that underlies hypertension, atherosclerosis, and stroke [15,16].
This work demonstrates how the target-to-molecule pathway can move beyond classical signaling molecules into the realm of epigenetics, opening entirely new frontiers for precision therapies in both cancer and age-related vascular disease.
The translational impact of SMYD3 research is evidenced by patents from Professor Zhu’s team covering novel SMYD3 inhibitors and their use in treating cancer and vascular disorders. These patents protect chemical entities capable of selectively modulating histone methylation, establishing a foundation for first-in-class epigenetic therapeutics in oncology and cardiovascular medicine.
The Bidirectional Model: Advancing Integrated Drug Discovery
Together, these approaches illustrate a cycle of discovery that moves beyond the conventional linear model of drug development. By leveraging natural products for target deconvolution and employing target-based rational design for new chemical entities, this bidirectional framework bridges traditional knowledge and contemporary science, integrating basic research with clinical translation. This model provides a robust and efficient strategy for developing small-molecule therapies that address major unmet medical needs in cardiovascular disease, arthritis, and cancer.
*Notes: This article provides research teasers for each reference to showcase the novelties
List of Patents
Preparation Method and Application of Leonurine Sustained-Release Microspheres
Preparation Method and Application of a Small-Molecule Inhibitor of Histone Methyltransferase SMYD3
Preparation Method of SCM198 Gel for Treating Skin Injuries
Microsphere Formulation Loaded with S-Propargyl-Cysteine and Its Preparation Method
Mesoporous Silica Formulation Loaded with S-Propargyl-Cysteine and Its Preparation Method
Endogenous Hydrogen Sulfide Sustained-Release Formulation: Preparation Method and Application
References
[1] https://www.who.int/health-topics/cardiovascular-diseases
[2] S. Luo, S. Xu, J. Liu, F. Ma, and Y. Z. Zhu, “Design and synthesis of novel SCM-198 analogs as cardioprotective agents: Structure-activity relationship studies and biological evaluations,” European Journal of Medicinal Chemistry, vol. 200, p. 112469, Aug. 2020, doi: 10.1016/j.ejmech.2020.112469.
[3] Z. Song, K. Song, Y. Xiao, H. Guo, Y. Zhu, and X. Wang, “Biologically Responsive Nanosystems Targeting Cardiovascular Diseases,” CDD, vol. 18, no. 7, pp. 892–913, Aug. 2021, doi: 10.2174/1567201818666210127093743.
[4] Y. Li et al., “Scm-198 alleviates endometriosis by suppressing estrogen-erα mediated differentiation and function of cd4+ cd25+ regulatory t cells,” Int. J. Biol. Sci., vol. 18, no. 5, pp. 1961–1973, 2022, doi: 10.7150/ijbs.68224.
[5] Y.-Y. Qiu, J. Zhang, F.-Y. Zeng, and Y. Z. Zhu, “Roles of the peroxisome proliferator-activated receptors (Ppars) in the pathogenesis of nonalcoholic fatty liver disease (Nafld),” Pharmacological Research, vol. 192, p. 106786, Jun. 2023, doi: 10.1016/j.phrs.2023.106786.
[6] M. Huang et al., “The multifaceted anti-atherosclerotic properties of herbal flavonoids: A comprehensive review,” Pharmacological Research, vol. 211, p. 107551, Jan. 2025, doi: 10.1016/j.phrs.2024.107551.
[7] Song Z, Meng S, Tang Z, Yang X, He Y, Zheng Y, Guo H, Du M, Zhu Y, Wang X. Injectable leonurine nanocrystal-loaded microspheres for long-term hyperlipidemia management. Biomater Sci. 2023 Jun 27;11(13):4713-4726. doi: 10.1039/d3bm00211j.
[8] S. Liu et al., “Endogenous hydrogen sulfide regulates histone demethylase JMJD3-mediated inflammatory response in LPS-stimulated macrophages and in a mouse model of LPS-induced septic shock,” Biochemical Pharmacology, vol. 149, pp. 153–162, Mar. 2018, doi: 10.1016/j.bcp.2017.10.010.
[9] Y. Xiong et al., “ZYZ-803, a novel hydrogen sulfide-nitric oxide conjugated donor, promotes angiogenesis via cross-talk between STAT3 and CaMKII,” Acta Pharmacol Sin, vol. 41, no. 2, pp. 218–228, Feb. 2020, doi: 10.1038/s41401-019-0255-3.
[10] https://www.who.int/news-room/fact-sheets/detail/rheumatoid-arthritis
[11] W. Cai et al., “S-propargyl-cysteine attenuates temporomandibular joint osteoarthritis by regulating macrophage polarization via Inhibition of JAK/STAT signaling,” Mol Med, vol. 31, no. 1, p. 128, Apr. 2025, doi: 10.1186/s10020-025-01186-6.
[12] Q. Ding et al., “Signaling pathways in rheumatoid arthritis: implications for targeted therapy,” Sig Transduct Target Ther, vol. 8, no. 1, p. 68, Feb. 2023, doi: 10.1038/s41392-023-01331-9.
[13] Z. Tang et al., “Neutrophil‐Mimetic, ROS Responsive, and Oxygen Generating Nanovesicles for Targeted Interventions of Refractory Rheumatoid Arthritis,” Small, vol. 20, no. 20, p. 2307379, May 2024, doi: 10.1002/smll.202307379.
[14] Q. Ding et al., “A novel small molecule ZYZ384 targeting SMYD3 for hepatocellular carcinoma via reducing H3K4 trimethylation of the Rac1 promoter,” MedComm, vol. 5, no. 10, p. e711, Oct. 2024, doi: 10.1002/mco2.711.
[15] Q. Ding, C. Shao, P. Rose, and Y. Z. Zhu, “Epigenetics and Vascular Senescence–Potential New Therapeutic Targets?,” Front. Pharmacol., vol. 11, p. 535395, Sep. 2020, doi: 10.3389/fphar.2020.535395.
[16] Z. Lin et al., “Discovery of deoxyandrographolide and its novel effect on vascular senescence by targeting HDAC1,” MedComm, vol. 4, no. 5, p. e338, Oct. 2023, doi: 10.1002/mco2.338.
