The Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) was proposed to the Chinese Academy of Science (CAS) and the European Space Agency (ESA) following a joint call for science missions issued in January 2015. SMILE was proposed by a team of European and Chinese scientists, led by two mission Co-PIs, one from China and one from Europe. SMILE was selected in June 2015, and its budget adopted by the Chinese Academy of Sciences in November 2016 and the ESA Science Programme Committee in March 2019, respectively. SMILE will investigate the connection between the Sun and the Earth using a new technique that will image the magnetopause and polar cusps: the key regions where the solar wind impinges on Earth’s magnetic field. Simultaneously, SMILE will image the auroras borealis in an ultraviolet waveband, providing long-duration continuous observations of the northern polar regions. In addition, the ion and magnetic field characteristics of the magnetospheric lobes, magnetosheath and solar wind will be measured by the in-situ instrument package. Here, we present the science goals, instruments and planned orbit. In addition the Working Groups that are supporting the preparation of the mission and the coordination with other magnetospheric missions are described.

On November 6, 2024, the Parker Solar Probe flew past Venus to make the first accurate electric field measurement in the nightside Venusian magnetosphere. To achieve this result, the electric field antennas were current biased in a way never before experienced by an electric field detector at Venus. This biasing requirement, that the positive bias current in the Venus shadow be about equal to the electron thermal current, is discussed and illustrated. About one minute of useful electric field data in the eight minute nightside magnetosphere crossing was obtained, during which the only feature observed was a few Hz signal. This result, along with the magnetic field measurements, showed that there were few if any electromagnetic waves, such as low frequency electromagnetic turbulence or whistlers, in the nightside crossing. Instead, a few Hertz, purely electrostatic signal was found. This suggests that the interaction of the solar wind with an unmagnetized body having an ionosphere may be different from that of previously studied magnetized bodies. In the sunlit flanks, many electromagnetic wave modes were observed. An additional result of this research is development of an improved algorithm for biasing electric field antennas in the Sun’s shadow which improves on guessing the bias current as done in this research.

Small bodies exist in distinct populations within their planetary systems. These reservoir populations hold a range of compositions, which to first order are dependent on formation location relative to their star. We provide a general overview of the nature of the reservoirs that source exocomets, from the influence of the stellar environment through planetesimal formation to comparisons with Solar System populations. Once transitioned from a young protoplanetary disc to a debris disc, a star can expect to be rained with exocomets. While exocomets are predominantly detected to date at A-type stars, planetesimals plausibly exist across a range of stellar masses, based on exoplanet abundance, debris disc occurrence and white dwarf infall.

Observing Cusp High-altitude Reconnection and Electrodynamics (OCHRE) is a student/early career researcher (ECR) focused sounding rocket that will fly as a compliment to the TRACERS satellites. OCHRE will utilize the deep institutional knowledge of the TRACERS science team to educate and mentor a team of graduate students and ECRs to serve as instrument leads, project manager, and primary investigator. Aiming for a near conjunction with, and at an apogee above, TRACERS in the northern polar cusp, OCHRE will answer some remaining questions from the TRICE-II sounding rockets using TRACERS to contextualize observations in the larger-scale polar cusp dynamics.

Most our knowledge about rocky exoplanets is based on their measure of mass and radius. These two parameters are routinely measured and are used to categorise different populations of observed exoplanets. They are also tightly linked to the planet’s properties, in particular those of the interior. As such they offer the unique opportunity to interpret the observations and potentially infer the planet’s chemistry and structure. Required for the interpretation are models of planetary interiors, calculated a priori, constrained using other available data, and based on the physiochemical properties of mineralogical phases. This article offers an overview of the current knowledge about exoplanet interiors, the fundamental aspects and tools for interior modelling and how to improve the contraints on the models, along with a discussion on the sources of uncertainty. The origin and fate of volatiles, and their role in planetary evolution is discussed. The chemistry and structure of planetary interiors have a pivotal role in the thermal evolution of planets and the development of large scale properties that might become observables with future space missions and ground-based surveys. As such, having reliable and well constrained interior models is of the utmost importance for the advancement of the field.

The Mapping Imaging Spectrometer for Europa (MISE) is an infrared compositional instrument that will fly on NASA’s Europa Clipper mission to the Jupiter system. MISE is designed to meet the Level-1 science requirements related to the mission’s composition science objective to “understand the habitability of Europa’s ocean through composition and chemistry” and to contribute to the geology science and ice shell and ocean objectives, thereby helping Europa Clipper achieve its mission goal to “explore Europa to investigate its habitability.” MISE has a mass of 65 kg and uses an energy per flyby of 75.2 W-h. MISE will detect illumination from 0.8 to 5 μm with 10 nm spectral resolution, a spatial sampling of 25 m per pixel at 100 km altitude, and 300 cross-track pixels, enabling discrimination among the two principal states of water ice on Europa, identification of the main non-ice components of interest: salts, acids, and organics, and detection of trace materials as well as some thermal signatures. Furthermore, the spatial resolution and global coverage that MISE will achieve will be complemented by the higher spectral resolution of some Earth-based assets. MISE, combined with observations collected by the rest of the Europa Clipper payload, will enable significant advances in our understanding of how the large-scale structure of Europa’s surface is shaped by geological processes and inform our understanding of the surface at microscale. This paper describes the planned MISE science investigations, instrument design, concept of operations, and data products.

We summarize mineralogical and compositional results from lab and in-situ spacecraft investigations of samples of comets 81P/Wild 2 and 67P/Churyumov-Gerasimenko which provide constraints to early solar system evolution. Wild 2 cometary solids were mineralogically similar to anhydrous chondritic Interplanetary Dust Particles with the exception that GEMS have not between reliably reported in the former. Important similarities include the very wide range of olivine and pyroxene bulk compositions (including minor elements), which probably reflects a wide range of sampled grain formation environments. The abundance of presolar materials in the Wild 2 samples is also approximately equal to that in anhydrous chondritic Interplanetary Dust Particles rather than being dramatically higher. High-temperature aggregates including chondrules (mainly type II), CAI and AOAs are also present in Wild 2, but probably at less than 10% overall total abundance. There was a pre-mission expectation that comet solids would be dominated by either non-crystalline materials, nanoscale crystalline materials, or presolar grains. None of these expectations proved to be correct. Organic matter was only well preserved in a few examined samples. These exhibit complex organic bonds, including mainly alkenes, aromatic C = C and carboxyl C = O, in a variety of textures including nanoglobules. The organic matter in Wild 2 samples show spectral similarities with that of insoluble organic matter (IOM) from carbonaceous chondrites. The chronology of the collected solids has not been well established, but there is no evidence for captured live 26Al, which could indicate accretion after this nuclide had effectively completely decayed. The implications of these major results are that Wild 2 sampled widely across the entire solar nebula, much wider than any other known astromaterials, potentially at a relatively late time compared to the oldest available astromaterials. A final caution is that the captured Wild 2 materials described here possibly derived from a small number of interior regions of a single Jupiter Family comet. There is also limited mineralogical information from comet 67P provided by the Rosetta Mission. The investigated 67P dust particles also contained about 45 weight% of solid organic matter, and is similar to the IOM extracted from carbonaceous chondrites. The H/C ratio of 67P IOM is about twice that of most carbonaceous chondrite IOMs and about 5 times that measured in asteroid Ryugu whole-rock samples, but lower than the H/C ratio of volatile species measured in the 67P coma. This high H/C ratio in the coma species is in turn compatible with that of the soluble organic matter in investigated carbonaceous chondrites such as Murchison. The average N/C ratio of 67P dust particles is about one order of magnitude lower than the solar photosphere value, but it is compatible with that of primitive carbonaceous chondrite meteorites and of Ryugu IOM.