The night off 17 February 1991 I was walking the night shift watch on the military base off Soesterberg in the Netherlands. Along with a other cadet I came at the central parking lot at 03.00 hour and notes a big circle in the sky strait on top off us. It had no shape but only bight lights slowly rotating anti-clockwise and the light points its self didn't rotate, the colours did ant in a liquid manor. I estimate the object abbot 30/50 meters in diameter. The first thing we both thought was a blimp, a zeppelin, the one like GoodYear has with the light screens on the sides. But the fact that it was very low and absolutely stationary and silent made its very, very odd. After some minutes the lights started to rotate faster and suddenly it took off at really incredible speed to the west. A couple off seconds later we felt a short hard wind blowing staid on top of us like a downwash from a helicopter. If there was a way to describe the speed this thing was going then I give it but I cant. We had a clear view for over 30 km that's +- 20 miles ? this thing cover that distance from stationary in some ting like 0.10 sec I know aviation and have flying experience and I am very technical. This kind off extreme acceleration turns humans in to liquid. For many year this has been a unspoken chapter in my live, I didn't wanted to speak about the incident because instantly after the encounter, me and the other cadet became unexplainable very, very ill, and for days suffered a hi fever and extreme vomiting. The illness was so bad that it left me traumatised and not able to speak about it for years.