Mercury Radiometer & Thermal Infrared Spectrometer, Phase E/F1 (MERTIS)

Basic data for this project

Description

BepiColombo is an interdisciplinary community mission of the European Space Agency (ESA) in close cooperation with the Japan Aerospace Exploration Agency (JAXA) with the aim to examine the planet Mercury in detail. In 2016 this challenging mission will be launched to Mercury. Equipped with two orbiters they should explore after a 6-year flight time the planet Mercury, which still raises many scientific questions today. Mercury is possibly the key to the history of our solar system. Its surface structure can at least help to understand how the solar system was formed about 4.6 billion years ago. The BepiColombo mission consists of three modules, the two orbiters (MPO and MMO) and the Mercury transport module (MTM). The Mercury Planetary Orbiter (MPO), which includes the MERTIS instrument, is being built on behalf of ESA and the Mercury Magnetospheric Orbiter (MMO) is contributed by JAXA. While the MPO will put its scientific focus on exploring the surface and the composition of the planet Mercury, the MMO will study the magnetosphere of the planet. The eleven scientific instruments of the MPO will explore Mercury from a near-surface orbit. This orbiter will circle the planet at low altitudes (up to max. 1.500 Miles) in a polar, elliptical orbit. Thus, the selected orbit allows precise mapping of the surface and exploring its composition. In addition, conclusions can be drawn also on the planet core. Selected by ESA to be one of the eleven instruments aboard the MPO spacecraft of the BepiColombo mission, MERTIS will map the surface mineralogy of planet Mercury with a spatial resolution of at least 500 meters. It is an imaging spectrometer covering the thermal infrared, or IR, range and also contains a radiometer for thermal inertia measurements.The goals of Phase E/F1 are to integrate the instrument on the spacecraft, the preparation of the instrument for launch, and its commissioning in orbit The magnetosphere of Mercury is explored with the MMO. This orbiter will circle the planet at higher altitudes (up to max. 12.000 km) in a highly elliptical orbit. Selected by ESA to be one of the eleven instruments aboard the MPO spacecraft of the BepiColombo mission, MERTIS will map the surface mineralogy of planet Mercury with a spatial resolution of at least 500 meters. The six instruments on board the MMO investigate the interaction of the magnetosphere and solar wind. The flybys of NASA's Mariner 10 in 1974 and 1975 detected a weak but constant magnetic field on the planet Mercury. This discovery was unexpected since aside from Earth the other terrestrial planets Venus and Mars do not have a global magnetic field, although they are more massive than Mercury. According to current knowledge, the planetary cores are responsible for maintaining the planetary magnetic fields. However, a part of the core must be in a liquid state. This is difficult in the case of Mercury due to its small size. The planet probably has a metallic core, which fills nearly half of its volume. Although the planet is only about 40 percent larger than Earth's Moon, Mercury has a density that is equal to the twenty more massive Earth. This is unusual, since the gravitational compression of Mercury should not allow such a high density because of its low mass. BepiColombo will be able to contribute fundamental information for a better understanding of the internal structure, the core and the magnetic field of Mercury. Owing to the low gravity and the strong influence of direct solar wind, the planet has no atmosphere. Its surface is thus exposed over long periods of the particles and the radiation of the sun. This has a major impact on the composition and structure of the surface minerals. However, it is the magnetosphere of Mercury which favors the existence of the exosphere, an extremely thin gas mixture of solar wind particles and particles that are released directly from the near-surface layers. The influence of solar wind on the composition and structure of Mercury's surface is still poorly understood. BepiColombo will be able to provide crucial data on this subject. Mercury is an extreme planet that orbits the Sun at a distance 58-69 million km in a relatively eccentric orbit. The surface temperature can reach up to 440 ° C. Nevertheless, due to the orbit craters exhibit permanent shadows with temperatures as low as -170 ° C. Therefore, some of these craters could contain water ice. Furthermore BepiColombo could make significant contributions on the open questions in connection with the volatiles on Mercury. Equipped with advanced camera systems and spectrometers BepiColombo (in particular the MPO including MERTIS) will allow a detailed study of the geology and mineralogy of the surface of Mercury. Specially, there are questions to volcanic and tectonic evolution of the planet and its impact history. In summary, the following questions can be formulated on a mission to Mercury: What about the origin of the solar system provide Mercury? How was the geological, mineralogical and thermal evolution of Mercury? Does the impact history tell us something about the evolution of the solar system. What are the physical properties (e.g. thermal inertia) of the surface of Mercury? Why is the uncompressed density of Mercury significantly higher than those of all other terrestrial planets? Is the core of Mercury liquid or solid? Is Mercury still tectonically active? Why has such a small planet a constant magnetic field? Why do spectrographic studies of Mercury show such a low proportion of iron oxide, even though iron should be the main component of the planet? What is in the permanently shadowed craters? Is there an evidence for ice? How arise the so-called "hollows" found MESSENGER? How can the exosphere of Mercury kept in balance? How interacts the magnetic field with the solar wind, while no ionosphere exists? Is there appearances as auroras, radiation belts or storms in the area of the magnetic field similar to that on Earth?