silver oval shaped object with circular shinning lights

the object seen was an oval shape. silver and looked like it had a white lining around if and had 3 blinking lights that went in a circle. it was bigger than a plane and u could tell it was because a plane was headed in the direction but was much smaller than the UFO. it stayed still and didnt move but when it did it only moved straight up and then back down resting from where it started. it was seen in tracy california and in the direction of 580 northwest headed toward livermore. four people witnessed the sighting. i am a currently a high school student at the age of 16, my sister at the age of 11, my mother who is somewhere in her forties and her friend ((name deleted)) who is goin to school to be a realtor.