Very large triangle of star-like lights but a little brighter seen to the South, approx 40 degrees above horizon 11.10pm Southend on Sea, UK. The area between the lights appeared opaque/filled/black and no stars/atmosphere seen in that area. The 3 lights at the apparent corners moved East together, drifting slowly which is how it caught my eye (I may have took them for bright stars without the movement). The object was very large, I would estimate the size of a 747 at about 500ft away perhaps. I ran indoors to get camera after viewing it for approx 10 seconds, I returned within 5 seconds with my camera phone, but there was no sign of the object anywhere in the sky.