I will be privileged enough to observe a total eclipse of the sun during early December from the northern parts of The Republic of South Africa. Standing on a hill and observing the SURFACE OF THE EARTH as the total eclipse approaches - will I be able to see the shadow of the moon streaking towards me? (i.e. like an aeroplane's shadow streaking over the surface of the earth?) And if so at what speed will it approach?
The speed of the shadow will depend on the time of the day. The shadow will move faster during evenings and mornings than during noon. This is due to the spherical geometry of the Earth. During noon, the speed of the shadow is about 0.55 km/s, whereas near mornings and evenings, the speed is higher at about 1.7 km/s. As you can see, this is really fast, and so it is unlikely that you will be able to see the shadow streaking towards you. Further, the brightness of the day is continuously decreasing as the eclipse progresses and it will be harder to see the shadow as it is quite dim before totality.
This page was last updated June 28, 2015.