This paper treats the oblique impact of a water drop onto a smooth optical glass surface at room temperature. The impact angle between the incoming drop and the surface is 45degrees. The preimpact diameter of spherical drops is 2.55 mm. The time evolution of the water/solid direct contact area is observed from the reverse side of the impact surface by a flash-photographic technique. It is found that the drop directly contacts the solid surface in a ring shape, and some air is entrapped between the bottom of the drop and the solid surface. Thereafter, a bubble is formed at the impact point. For the case of impact velocity at 1.31 m/s, a fingering pattern is developed from within a ring-shaped wet area, then satellite bubbles in a ring are formed around the bubble at the impact point. No satellite bubble is observed for the case of a higher impact velocity (= 2.11 m/s). (C) 2004 Elsevier Ltd. All rights reserved.