Luminous clouds are atmospheric formations that emit light, often appearing during specific weather conditions. These clouds can be seen during phenomena like sunset or sunrise, when the sun's rays scatter through the atmosphere, creating vibrant colors. They can also occur during thunderstorms when lightning illuminates the clouds from within. Another type of luminous cloud is the noctilucent cloud, which forms at high altitudes and glows in the night sky. These clouds are made of ice crystals and are best observed during twilight. Their ethereal glow is a result of sunlight reflecting off the ice particles, creating a stunning visual display.