While i was working on a building site in adelaide australia, i was on top of some scaffolding g waiting for my labourer to bring me some more materials. i was looking at the view as it was a lovely sunny day. i noticed a very large almost transparent sphere hovering just under the cloud line, it was moving slowly around a small area. when my labourer came up to the top top of the scaffolding i pointed the sphere out and asked him if he could see it, which he could. we watched it for a further 20 mins, then in moved upwards through the clouds. the clouds dispersed as it passed through. then the sphere carried on climbing until out of sight. my labourer who was a local to adelaide informed me there is an air force base in that area where the sphere was hovering. the sphere seemed to be very large. i just want to know if anyone has seen a similar object.