At approximately 4.00 - 4.30pm in the afternoon myself and my 8 year old granddaughter were outside my residence at the top of my driveway saying goodbye to visitors. after visitors had left my granddaughter asked if i would stay outside with her for a while. after about 2 mins my granddaughter asked me 'what is that light behind the plane?' i turned to where she was looking and saw a plane approaching us from perth city. the plane had a bright light near the rear of it but i thought it was a reflection from the sun bouncing off of one of the planes windows. as the plane drew nearer i could see that the light was actually behind the plane. as the plane drew closer still i could see that it was not one light but three lights in formation following the plane (one light in font two behind). they appeared like the brightest stars i had ever seen. as the plane flew over the lights came to a stop right above us and remained there just hanging in the sky. i remember just starring at it trying to work out what it was. satellite?....Too low. drone?....No mechanics seen anywhere between the points of light. new plane tracking technology. i was not frightened just completely perplexed. i remember actually asking my granddaughter the same question about three times whilst starring at the lights 'can you see that'. after the third time she started laughing pointing out that she had brought the light to my attention in the first place. i viewed the three lights (triangle shape) hanging there above my head for a good 5 mins. all of a sudden i thought that i should try to film this event. i ran inside and grabbed my camcorder and when i came back outside the three points of light had started to slowly ascend. the card on my camera was full and by the time i had sorted this (another couple of minutes). by this time the triangle lights were only three really small white dotes barely discernable. for the next few days / weeks i kept checking newspapers / tv news and internet to see if anyone else had seen these lights but i saw nothing. it was only really 18 months later when i had leave from work that i started investigating. apparently these are seen quite frequently all over the world and no one knows what they are!! regards marilee