We saw/heard a large triangular black object. lights - red, green and white. It made a very loud humming sound which caused us to move into the open (we were camping at the time) where we both clearly saw it. Thought it might have been a drone but was way too big for anything that i know of. Not supper fast moving - not as fast as a plane or a helicopter. Approximately 9.30 pm we heard/saw it. It may have been a little later It was a very clear night, lots of stars and no clouds. We saw it for about 15 to 20 seconds when we lost sight of it as it was moving across the top of the trees. Difficult to know how high it was, but again, less high than a light aircraft would fly. Maybe 100m to 200 m above us... hard to know exactly. No other people were camping around us and so we were by ourselves in the National Park. The object did come from the direction of the Mareeba airport/airdrome but i have not been successful in getting information from them. It would have been flying roughly east. Unfortunately, we were both transfixed and did not have time to capture a photo. Our phones were off as there is no cellular reception there. Anyway, i am very curious and wondered if you may have some way of finding out what it might be. I have gone through Radar Box to but can only see flights. This was definitely not a light aircraft. I hope i hear from you with any information you might have.