December 11: International Mountain Day. Today is International Mountain Day, set by the United Nations. Mountains collect much of the fresh water we drink and are home to countless animals and plants. The highest mountain in the world is Mount Everest, 8,849 m tall.
1781 💡 Scientist David Brewster was born in Scotland. He studied how light bends and reflects, and he invented the kaleidoscope, the tube toy full of colourful patterns.
1863 🔬 Astronomer Annie Jump Cannon was born in Delaware, USA. She sorted hundreds of thousands of stars by their light, creating a star classification system still used today.
1972 🚀 Apollo 17 landed in the Moon's Taurus–Littrow valley. It was the sixth and final Apollo Moon landing, and its astronauts drove a lunar rover across the surface.