Our planet is all land, oceans and clouds in the daylight. But how does look Earth at night? At night it becomes electric with all the human-built sources of light. This satellite photo shows how our planet and its continents glow at night. You can also trace which areas on Earth are most densely populated.
It is very easy to discern how parts of the US, Canada, Europe and all of Japan are the brightest at night. Although the photo is beautiful, it raises some serious issues too. With this image you can introduce the phenomenon of light pollution, highlight our waste of energy, discuss ways of saving energy.