I live in a small town about 10 miles north of san francisco. it was a bright sunny morning and i was at home. i had opened the door to let my cat out on the deck like i do every morning. he ran out and stopped on a dime, looked up at the sky, then ran back into the house with his ears flat back. i stepped out onto the deck to see what had scared him. i looked up and saw a round object in the sky to the north. i immediately knew it was a ufo because i've seen three others prior to this. it was about the size of a small pea in the sky, and was fairly close, i'd say about 400-500 feet high and about 1000-1500 feet in the distance. it was spherical in shape, very light gray in color with whitish fuzzy edges. the surface was dull, not shiny, and i noticed it appeared to be reflecting sunlight. there were no distinguishing features - no portals, lights, colors or sound. when i first saw the ufo it was moving northwest very slowly in a zigzag path, but then it abruptly turned and came directly towards me. it got close enough to be about the size of an aspirin when it stopped and hovered in the air for about 8-10 seconds. i got the impression it was checking me out. as i watched it it morphed into a square with rounded corners then back to a sphere again. this happened 3-4 times. the grey color and white edges remained the same. it began to slowly move away from me, resuming its zigzag path to the northwest. i got the feeling it was looking for something. suddenly it just disappeared, just winked out. the entire sighting lasted 40-45 seconds. this was a strange encounter. when i first saw this ufo i felt dread - i don't know why. then when it came directly towards me i was paralyzed by fear. when it stopped and hovered i wondered if it was trying to communicate with me. once it began moving away from me i suddenly realized that i was calm and unafraid, as if i hadn't just experienced something extraordinary. as for my cat, he was scared and jumpy for about a week after this incident.