I was leading a tour in Nikko Japan. After dinner at a local restaurant, me and another guy walked back to the hotel at around 10pm. The other guy was an astronomer so we were looking at the night sky and talking about the stars that were easy to see high up in the mountains.I saw what looked like a satellite moving in space. I usually can see satellites that looked like this slow moving white lighted object. I mentioned to the other guy to look at it.It then came at a very high rate of speed out of space toward out location. It got bigger and you see see a triangle outline with a light on each tip of the triangle shape.It was completely silent.It then stopped and hovered right over us for 5 seconds then pivoted to the left and slowly moved until it was out of site past the next mountain top.The guy was walking with freaked out and ran when it pivoted to the left silently. The whole time it never made a sound and was about the size of a football field. I could tell the size because it was very low and you could compare against the trees and mountains.It worthy to note that it was the same night Obama came to Japan.