Bright Blue semi-transparent illuminated sphere on a flat trajectory 1000' above valley floor streaked the sky and suddenly dissapearedI stepped outside to check the night sky for possible rain. The time was approximately 20:45 pm central time in Cuidad Colon, Costa Rica. The sky was very dark but some clouds could be seen. My location is near the top of a ridge approximately 3000’ elevation overlooking a deep river valley below, and the other side of the valley about 5 miles as a crow flies is a higher mountain about 4500’. There are no lights at night or anywhere in the whole area to be seen at night. I was standing there for about three minutes and directly across from my location at 3000’, I saw a bright blue sphere shaped semi-transparent object that illuminated the space of a 10 foot diameter sphere with no sound what so ever very rapidly (faster than a jet aircraft) travel on a flat trajectory for approximately 3 sec. or one mile and then just like that completely disappeared without any effects, sound or anything.