Anomalous zoneThe Hessdalen Valley
A Norwegian valley where luminous objects have been observed since 1981, at times twenty times a week. Unlike most such places it has a permanent automated observation station, built in 1998 by Østfold University College, and the phenomenon has been under instruments for a quarter of a century. Hypotheses exist — dust ionisation, a piezoelectric effect in the rock — and none accounts for all of it.
