Hidden volcanoes hint at Moon’s turbulent past

Hidden volcanoes on the Moon suggest a more dynamic and geologically active history than previously thought, according to new findings published in Geophysical Research Letters. Two massive shield volcanoes, long overlooked, have been identified using data from NASA's Lunar Reconnaissance Orbiter. These structures, located near the Moon's equator, challenge existing models of lunar geological evolution and provide fresh insights into the Moon's internal processes. The newly discovered volcanoes, named Prinz-Harbinger and another unnamed structure nearby, span approximately 80 kilometers in diameter. Shield volcanoes, typically associated with fluid lava flows, are rare on the Moon due to its small size and lack of plate tectonics. Their presence indicates periods of intense volcanic activity, possibly linked to ancient mantle plumes or deep-seated magmatic intrusions. The Prinz-Harbinger volcano, in particular, is partially obscured by smaller impact craters and irregular terrain features, making it difficult to detect without high-resolution imaging. Researchers used advanced image processing techniques to analyze topographical data collected over several years by the Lunar Reconnaissance Orbiter. By combining elevation measurements with spectral analysis, they were able to distinguish the subtle bulges of the shield volcanoes from surrounding features. The study suggests these structures formed billions of years ago, during the Moon's early history when it was still geologically active. The discovery adds to growing evidence that the Moon's surface has been shaped by complex and varied geological forces. Earlier studies had identified smaller volcanic features, such as sinuous rilles and domes, but shield volcanoes of this scale were unexpected. Scientists believe the Moon's interior may have retained heat longer than previously assumed, allowing for sustained volcanic activity. The research team included planetary scientists from multiple institutions, including the Lunar and Planetary Institute and the University of Arizona. Lead author Liang Qiao emphasized that the findings could reshape understanding of lunar geology. "These volcanoes indicate that the Moon's interior was more active and heterogeneous than we thought," Qiao stated in a press release accompanying the study. The implications extend beyond the Moon itself. Similar geological features observed on other celestial bodies, such as Mars and Venus, might also benefit from reassessment. Understanding how shield volcanoes form on airless worlds can help scientists better interpret data from future missions exploring these planets. Some researchers remain cautious about the conclusions drawn from the study. While the imaging data is robust, some experts argue that additional ground-based observations or sample return missions would be necessary to confirm the nature of these structures. Others point out that the Moon's thin crust and low gravity make shield volcanism less likely compared to Earth, though not impossible. NASA officials expressed interest in further studying the region where the volcanoes were found. The agency plans to incorporate the new data into upcoming mission planning, potentially guiding future landings aimed at collecting samples from areas with complex geological histories. The findings could influence the selection of landing sites for both robotic and crewed missions, particularly those focused on understanding the Moon's volcanic past. The study appears in the latest edition of Geophysical Research Letters, a peer-reviewed journal published by the American Geophysical Union. It follows a series of recent discoveries that have expanded the scientific community's view of the Moon as a geologically diverse body rather than a static, unchanging landscape. As technology improves and more data becomes available, the Moon's story continues to evolve, revealing layers of complexity once thought buried beneath its familiar gray surface.