Because Mercury rotates so slowly — once every 58 Earth days, compared to a Mercury year, a complete trip around the Sun, lasting only 88 Earth days — the part of the planet at dawn spends a disproportionately long time in the path of one of the solar system's primary populations of micrometeoroids. (sciencedaily.com)
Pokorný and his team hope that their initial findings will improve our understanding of the rate at which comet - based micrometeoroids impact Mercury, further improving the accuracy of models of Mercury and its exosphere. (sciencedaily.com)
The distributions of other species, like Mg and Ca, as observed by MESSENGER, peak at dawn, consistently with a release induced by micrometeoroid vaporization, assuming a preferential precipitation in the leading side (Burger et al. 2014). (swsc-journal.org)