Tokyo celebrated the Hotaru Festival (Firefly Festival) in style with the release 100,000 glowing blue LEDs orbs into the Sumida River flowing through the center of the city. After bobbing their way down the river, the special solar powered orbs were collected by giant nets so they could be reused.
So bright they could be seen lighting up the river from the sky, the orbs called "Inoriboshi" — which means prayer star — were created by Panasonic specifically for the occasion. Each light used a HIT photovoltaic cell, a rechargeable battery and an LED chip; a sensor on the bottom of the orb triggered it to light up when dropped in the water.
The river-borne light display was paired with the lighting of Tokyo's new Sky Tree tower to create a spectacular light show. The Sky Tree tower — the world's tallest tower — isn't scheduled to be officially opened until May 22 but the lighting provided an incredible nighttime preview.
Given the orbs were collected at the end of their journey hopefully they'll make an appearance at future Japanese festivals — their soft blue glow really transforms the River.