Drop the Moon, Mars, Mercury and other worlds onto Earth and compare their true size to any country — Mercator-correct.
Planets and moons are usually drawn side by side against a black background, which tells you their order but not their scale. This tool puts them on the map instead: the Moon, Mars, Mercury and other worlds rendered at true size over the country of your choice.
The Moon is smaller than Australia is wide. Mars would cover most of Africa.
Choose a world and move it over the map. It is drawn to the same scale as the land underneath, corrected for the projection, so the comparison holds wherever you put it.
GK Maps — Where Geography Meets Knowledge.