Corona discharge Corona discharge A corona discharge is an electrical discharge brought on by the ionization of a fluid such as air surrounding a conductor that is electrically charged. Spontaneous corona discharges occur naturally in high-voltage systems unless care is taken to limit the electric field strength. A corona will occur when the strength of the electric field (potential gradient) around a conductor is high enough to form a conductive region, but not high enough to cause electrical breakdown or arcing to nearby objects. It is often seen as a bluish (or other color) glow in the air adjacent to pointed metal
Vallis (planetary geology) may be related to lobate debris aprons, which have been proven to contain large amounts of ice. Reull Vallis, as pictured below, displays these deposits. Dao Vallis begins near a large volcano, called Hadriaca Patera, so it is thought to have received water when hot magma melted huge amounts of ice in the frozen ground. The partially circular depressions on the left side of the channel in the image below suggests that groundwater sapping also contributed water. Vallis (planetary geology) Vallis (plural "valles") is the Latin word for "valley". It is used in planetary geology to name landform features on