What is an altimenter?

Why do Bahai's use 19 month calendar? How do you conclude a rainbow? Who was the Astronaut who logged 1600 hours in space during seven space flights? How many potatoes can fill the sun? Who taught that the Earth is stationary and at the center of the universe with the Sun the Moon and the planets moving around Earth in perfect circles? What do people call meteors? What does selestial mean? When is Jupiter at its closest to the Earth when it is at what elongation position? Did Apollo 1 explode? What was Zeus connected to? How many rockets have gone into space and not come back? What is power shift? How long was the Saturn V rocket? Why does a satellite need to be high above the earth? What is a disk of matter that circles a planet and consist of numerous particles in orbit that range in size from a few millimeters to several hundred meters? Why do rockets land on the moon backwards? How does Santa know your sleeping? What was the date 17 weeks ago? What color is formed by combining all color of light? Why dod they send rockets to the moon?