My grandson and his friend were on the East side of our house in the front yard and came in about 11:30 and woke my wife and I saying: "There are UFOs above the house!". I went out to see an orange/yellow round/sphere traveling behind a tree due east of us in a SE direction. It then seemed to diminish in size until it was gone. This first one had been gone for several minutes when another one of these objects appeared traveling in the same path as the first one from the NW and continued to the SE of us diminished in size to nothing in the same manner as the first one. I observed 3 more (I personally observed 5), all silent, not flashing, same steady luminosity traveling in a diagonal path from NW to SE just to the North of our house. My grandson and his friend stated they had observed 3 before waking my wife and I. They said the first two were traveling in parallel with a single one following (I dont remember if all 3 were visible to them at the same time). I have never seen any object or air craft that looked or behaved in this manner before and have no idea what they were beyond they were not any conventional craft I knew of. I was quite excited but couldnt really define any other emotion other than wonder beyond that. Did not feel fear. We live in the glide path for the local airport, PDX, and see many airliners and small planes pass over head at various altitudes. Several flew over during this event but I do not think any did so while any of the objects were visible. I also observed at least two high altitude planes, assuming they were passenger jets, complete with flashing colored and stationary white marker lights. The landing planes and high altitude planes I could probably make a guess at how high up they were, but I could not make this guess of the objects as I didnt have any good references near them. The only determination I feel safe in making is near the end of each objects path when they disappeared was that at the point they were beginning to diminish is that they were moving away from Earth at what must have been a great speed. There are several Youtube videos online, one on the same date and area, and several in the recent past of very similar if not exact descriptions of what we observed. My grandson and also his friend took some photos, a Fuji digital camera and and I phone 4 but none of which did justice to what was observed. My wife also observed at least 2 or 3 of these object with very similar feelings of having never seen anything like them in her life and had great wonder as to what they could be.