Metallic and molecular ions in the magnetosphere are so minor that contribution even from the Moon and meteoroid might be detectable in addition to the ionospheric and solar wind origin. Thus, this topic needs interdisciplinary efforts.

In the magnetosphere, heavy ions have been found already in early 1970’s. Since then, the magnetospheric ion dynamics has long been studied with four major components (H⁺, He⁺⁺, He⁺, and O⁺). Both helium and oxygen have been used as markers for plasma coming from the solar wind (He⁺⁺), plasmasphere (He⁺), and ionosphere (O⁺), respectively, while we cannot distinguish the origin of H⁺ where from. The minor components thus give important information on the source and transport. This applies to the even less-abundant minor ions such as molecular ions and metallic ions. For example, the molecular N₂⁺, NO⁺, or O₂⁺ ions, compared to the atomic O⁺ ions (without separating from N⁺), carry certain important information on the internal processes in the ionosphere as well as the ion outflow processes above the ionosphere. The metallic ions give information on the mesospheric heavy ions and even the lunar-origin ions.  With such unique information, heavy molecular and metallic ions in the terrestrial magnetosphere can contribute understanding the geospace environment in many aspects: the ion escape process from the ionosphere, related ionospheric and even mesospheric process, deposition of near-Earth small bodies at different altitudes, solar wind-magnetosphere interaction, and even the dynamics of the Moon-origin ions.

Unfortunately, these heavy ions and atoms are vastly unexplored in near-Earth space.  Only a few terrestrial missions have been equipped with instrumentation dedicated to separate these molecular and metallic ions, within only a limited energy range and limited mass range. This is far too limited to make any quantitative discussion on the very heavy ions in the magnetosphere. Under this circumstance, it is worth to re-examine, using available tools, the existing data from the past and on-going missions, including those not designed for the required mass separation, to search for these ions.

Such works require gathering of scientists from several different disciplines: Solar wind, the Moon, Magnetosphere, Ionosphere, Mesosphere, and Meteor ablation, including spacecraft observations, ground-based observations and models. By gathering experts from these very diverse field, this interdisciplinary ISSI team first made a list of relevant data, most of which are taken by instruments not designed for heavy molecular or metallic ions, because re-examination of these data and combining different observations and with viewpoint of molecular and metallic ions with the most recent knowledge gives new insights of these data.  The team actually examined some cases, identifying a new supply route of very heavy ions, while concluding that the existing dataset is far from being sufficient to access the relative importance among the Moon, mesosphere, or the solar wind as the source of the low-charge state metallic ions.  Another unanswered but urgent problem discussed during the team meetings is possible contaminate by the ablated space debris which is increasing rapidly in recent years, because some metals that are commonly found in the space debris (e.g., aluminium Al, copper Cu, and titan Ti) are relatively rare in the magnetosphere.

To understand these question and even /monitor space debris-origin, we need dedicated observations.  We discussed the needed measurements and possible implement in the future missions.  All the result would be reported in a review paper.