First Halley multicolour camera imaging results from Giotto

The first imaging results from the Halley Multicolour Camera during the Giotto fly-by of comet Halley provide images centred on the brightest part of the inner coma which show the silhouette of a large, solid and irregularly shaped cometary nucleus and jet-like dust activity visible in reflected sunlight. The nucleus is at least 15 km long and ≡10 km wide; its geometrical albedo is very low (< 4%). Only minor parts of the surface are active, most of it being covered by non-volatile material. Dust jets dominate the inner coma and are restricted to the sub-solar hemisphere. Preliminary interpretations of these observations are presented