- The Moon is Earth’s only natural satellite. It orbits around Earth at an average distance of 384399 km (238,854 mi; about 30 times Earth’s diameter). The Moon is tidally locked to Earth. This makes the Moon’s near side face Earth always the same way, and synchronizes its rotation period (lunar day) to its orbital period (lunar month) of 29.5 Earth days. Conversley, the Moon’s gravitation causes tidal forces on Earth, which are the main driver of Earth’s tides.
- Josh Kirby (Wikipedia)
Ronald William “Josh” Kirby (27 November 1928 – 23 October 2001) was a British commercial artist. Over a career spanning 60 years, he was the artist for the covers of many science fiction books including Terry Pratchett’s Discworld novels.