Special issue of Planetary and Space Science 'DEMETER'

摘要

DEMETER is the first in the Myriade series of micro-satellites developed by the CNES for low-cost science missions. This mission was decided following the recommendations of the Comite des Programmes Scientifiques (CPS) of Centre National d'Etudes Spatiales (CNES) after the scientific exploratory seminar of Arcachon in 1998. DEMETER, a Greek goddess of the Earth, is also the acronym for Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions. Its scientific objectives are the detection and characterisation of the ionospheric perturbations associated with natural phenomena (such as earthquakes, volcanic eruptions, tsunamis) or with anthropogenic activities. DEMETER is not an operational satellite and it will not predict earthquakes. People have been aware of electromagnetic disturbances during seismic activity for centuries. Stories of compasses spinning and flashes of light in the sky appear in ancient texts, but, for lack of scientific evidence, they have long been viewed with scepticism. Disturbances of this kind could serve as warning signs if they can be shown to be real and systematic. This is one of the challenges DEMETER faces.