Schmid Daniel, Lammer Helmut, Berezhnoy Alexey A, Weichbold Fabian, Scherf Manuel, Varsani Ali, Volwerk Martin, Simon-Wedlund Cyril, Baumjohann Wolfgang, Nakamura Rumi, Murakami Go, Plaschke Ferdinand
Space Research Institute (IWF), Austrian Academy of Sciences (OeAW), Schmiedlstrasse 6, Graz, 8010, Austria.
Sternberg Astronomical Institute, Moscow State University, Universitetskij pr. 13, Moscow, 119991, Russian Federation.
Nat Commun. 2025 Jul 5;16(1):6205. doi: 10.1038/s41467-025-61516-4.
Mercury's exosphere contains various neutral species, including hydrogen, helium, sodium, potassium, calcium, magnesium, aluminum, iron, and manganese. Although lithium has been predicted to exist, it had not been detected until now. Here, we demonstrate the presence of lithium in Mercury's exosphere, using data from the Mercury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft. The sporadic detection of lithium suggests its meteoritic origin, likely released through evaporation caused by sporadic meteoroid impacts. Our findings provide strong evidence supporting the hypothesis that (micro-)meteoroids and larger meteoroids, which have continuously and sporadically impacted Mercury's surface over billions of years, are a significant source of volatile elements and contributed substantially to Mercury's unexpectedly volatile-rich surface. This detection emphasizes the significant role of meteoroids in shaping Mercury's exosphere and provides insights into the planet's evolution and the history of volatile elements in the Solar System.
水星的外层大气包含各种中性物质，包括氢、氦、钠、钾、钙、镁、铝、铁和锰。尽管预计锂也存在，但直到现在才被探测到。在这里，我们利用来自水星表面、空间环境、地球化学和测距宇宙飞船的数据，证明了水星外层大气中锂的存在。锂的零星探测表明其起源于陨石，可能是由零星的流星体撞击引起的蒸发释放出来的。我们的发现提供了有力证据，支持了这样一个假设，即数十亿年来持续且零星撞击水星表面的（微）流星体和较大的流星体是挥发性元素的重要来源，并对水星表面意外富含挥发性物质起到了重要作用。这一探测强调了流星体在塑造水星外层大气中的重要作用，并为该行星的演化以及太阳系中挥发性元素的历史提供了见解。
