Polaris, the North Star, is not the brightest star in the sky. It ranks only around 50th. Its importance comes from its position: it lies almost exactly above Earth’s North Pole, so it barely moves while the rest of the sky turns around it. Why it seems fixed Earth rotates around an axis. Extend that … Read more
A constellation is a pattern of stars that people have linked together and named. For astronomers today, it is also an official region of the sky, like a country on a map, so that every star and galaxy belongs to exactly one constellation. Stars in a constellation are not neighbors The stars of a constellation … Read more
A meteor shower happens when Earth passes through a stream of debris left by a comet, or occasionally an asteroid. The particles, mostly smaller than grains of sand, hit the atmosphere at tens of kilometers per second and burn up as streaks of light. Because Earth crosses the same streams every year, showers return on … Read more
The Moon does not make its own light. It reflects sunlight, and half of it is always lit by the Sun. As the Moon orbits Earth, we see different portions of that lit half. That changing view creates the phases. The eight phases “Waxing” means growing and “waning” means shrinking. How long is the cycle? … Read more
