We would take the mass given, 80 kg, and multiply it times the acceleration of Earth's downward pull on that mass, 9.8 m/s/s. So the weight on Earth is 784 newtons. So the weight of the same 80 kg mass on the moon is 133.28 N.
Gases and particles in Earth's atmosphere scatter sunlight in all directions. Blue light is scattered more than other colors because it travels as shorter, smaller waves.
