It's called a Schaufelradbagger or Rheinbraun bagger and it's big!
Bagger 288 for instance weighs 13000 metric tons (no really, 13000 tons, that's 13000 cars!!), is 240 metres long, 96 metres high and planetary defence is probably one of it's secret functions.
These Bucket-wheel excavators are the largest vehicles on this planet and they can be seen at a pityfull 140 kilometres from where I'm sitting right now !!!
If not soon then I'm certainly gonna see them with the kids (that will be around 2025, be patient and i'll blog about it when the time comes).
Things this big can of course be seen from the sky, if you're familiar with google earth you can go see them @ 50°53' N and 6°20' E and in a few other mines more to the east, you really can't miss these mines, they can be seen from at least 150 kilometres eye altitude, just go the the Belgian/Dutch/German border, and then into Germany.
The ultimate picture,
some more pictures,
and some action pictures
I bet these are the reason the martians, the decepticons nor the borg don't dare to attack us