Can't speak for the Cygolite, but I run the PlanetBike Super Blinky, and can confirm that it is visible from low-earth orbit. People have actually stopped and asked me if I know how bright my tail light is; riders I pass on the MUP curse my name; motorists are intimidated into a respectful follow distance; small animals flee into the underbrush as the red blinky terror approaches. I love that light.