Fr.: météorologie de l'espace
The varying conditions in space and specifically in the near-Earth environment. Space weather is chiefly solar driven, resulting from solar activities such as → solar flares, → solar wind, and → coronal mass ejections that affect → magnetosphere, → ionosphere, and → thermosphere. Non-solar sources such as Galactic → cosmic rays, → meteoroids, and → space debris can all be considered as altering space weather conditions at the Earth. Space weather may affect the performance and reliability of space-borne and ground-based technological systems and can endanger human life or health. The research in this field aims at monitoring and diagnosis of space weather conditions and constructing reliable numerical prediction models. See also → Space Situational Awareness.
Fr.: altération spatiale
The slight erosion of Solar System bodies (planets, moons, asteroids) caused by the → solar wind, → cosmic rays, and → micrometeorite bombardments. Space weathering affects the physical and optical properties of the surfaces of these bodies. Understanding this process is therefore important for the interpretation of remotely obtained spectral data, such as space probe photographs of outer Solar System moons.