UFO Sighting in Boston, Massachusetts on June 3rd 2015 – 3 glowing orbs in sky, 4th appeared later on. Orbs are in almost perfect arc

Got picked up from the airport around 8pm. Driving home on 93SB. It's June so it was ducky around 8pm, but still light out. 3 Orbs appeared in the east, almost in a perfect arc. Then a 4th appeared. They were stationary the entire time, probably saw them for ~10mins while driving (same direction at all times). Seemed to jump on either side of the highway as we went around bends, etc., but not sure if that's my own issue with perception. There were airplanes nearby (near Logan airport), and also airplanes in the sky. These orbs were not airplanes, as they did NOT move at all and did not emit the usual consistent, blinking lights an airplane does at night. Eventually we lost them over the tree line.