Two large, apparently sperical objects, glowing brightly in the deep red, approached from behind, passed overhead, and into distance.

I was travelling east on the interstate that passes through El Centro, approaching it but still maybe 10-20 miles west, when I noticed an unusual glow and realized that it was coming from above and behind me.  There were two large, apparently spherical objects, moving in absolute lockstep as though tied together structually, although I couldn't see any such connection, glowing so brightly that they lit up the desert with an erie deep red, possibly monochromatic light, displaying no other detail than two perfect circles of red light, which, at closest approach, each occupied about as much space in the sky as does a full moon.  They passed almost directly overhead, at a stately pace, and then seemed to very gradually accelerate and bank off to the left, moving rather quickly by the time they disappeared from sight. I stopped and took a motel room in El Centro, and heard on the news that either one or two helicopters (two I think, but I'm not sure on this point) from a nearby military base had crashed or somehow been destroyed that same evening.  I, of course, immediately assumed a connection, but made no attempt to report what I'd seen. There were other cars on the highway, so there must have been other witnesses, but I have no idea who or how many.
We have estimated the time of dusk at 1700 hrs.