1. INTRODUCTION
The Auroral Station in Adventdalen, Svalbard (78N, 15E) close to the town of Longyearbyen (LYR) is a multi-instrument platform for studies of dayside aurora. It is more or less completely dark during the day for more than 2 months in the middle of the winter. Near winter solstice the Sun is at least 14 degrees below the horizon. Hence, it should be almost completely dark in the daytime at Longyearbyen during the months of December and January. But to our surprise, on the 6th of December 2002, the South - East sky turned deep red from about 07:30 to 12:30 UT. The whole event caused great public attention. Speculations and questions about its origin were very soon directed to the Auroral Station. The Governor of Svalbard was on the alert and the local newspaper made headlines in Norway with the article "A mysterious phenomena" [Svalbardposten, no.49, 2002].

At the time of the event the station was fully operative with all its instruments, which were set up to study optical signatures of the dayside aurora. A remote controlled spectrometer located in Ny-Ålesund (NYA; 79N, 12E) was also operative. Ny-Ålesund is 118 km north of Longyearbyen. Fortunately, data from the OSIRIS instrument onboard the Odin satellite are now also available. In addition, data from the LIDARS at the Koldeway Station in Ny-Ålesund and at ALOMAR close to Andenes (70N, 16E) are also analyzed.

This study presents both the ground-based and the space borne measurements of the event. Finally, a discussion is given on what might be the cause of the red-sky event.