Tokyo-based engineering group NTT Facilities built a pair of Solar UFOs for the Aqua Metropolis festival in Osaka, Japan.

The solar-powered duo weigh in at 3.4 tons each and they are five feet tall and 16 feet in diameter. The machines are equipped with filtration systems that pump fresh oxygen into the water by day and are ringed by LED lights that turn on at night.

The Solar UFOs spray the clean water out of a nozzle at the top of the craft that in turn cools the panels, and they can purify 2,400 gallons of water each day. One will be deployed in a canal in central Osaka, while the other will keep the moat of Osaka Castle clean until March 2010.

Via Pink Tentacle