Sphere, No lights, moving through neighborhoods above tree tops, over busy streets in Houston in 1980.

I would describe the sphere as being 2xlarger than a bowling ball, matt finish, with a cylinder on top with a short thin bar protruding from it, and around the circumference of the cylindar four thin anntennae.  It moved silently in a straight line and performed flawless angled turn of direction without change in momentum.  I believe it stayed on the same plane and speed was approximately the speed of a car going down a residential street.  The closest it came to me was perhaps 20 to 50 feet away.  It altitude was approximately 25 to 35 ft above the ground.  
A flock of black birds split to fly around it.  When it reached my position it continued in another direction, approximately a 35 to 45 degree angle, until it was out of site.  I was alone, but it traveled over a very populated area and traffic.  Someone else has to have seen it.  I've written this today because I just read an entry of 2002 asking someone who may recognize a picture of a sphere found in the red clay in the woods near Huntsville, AL in 1984.  I saw my object in 1980, although I don't remember the day and exact time of my encounter.  It is similar to that, but with some noticeable differences.
Witness indicates that date of sighting is approximate.  PD