Our technological society has created many amazing things. Sometimes the things we create have unintended consequences. One of those is light pollution.
Looking into the night sky in a city can be a rather dull experience, even when you know there are no clouds up there! Why? It’s all due to something called scattering. Light produced from many different sources can bounce around in the atmosphere and become a diffuse “sky glow.” This background glow acts to reduce the contrast between the background of the sky and the tiny bright lights of the stars. Light from the brightest objects can still be seen in many cases – but faint objects are out of reach.
Thankfully there are some wonderful things to see at night that are bright enough to see in nearly any city on a clear night. Here are “the big five:”
- The Moon
- Jupiter – and the four Galilean Moons
- Saturn – and its biggest moon, Titan
The moon is big enough to present years worth of wonderful observing just as it is. The planets can present truly wonderful vistas – even with the naked eye.
In addition to the brightest of the planets, usually quite a few stars are visible in light-polluted areas. The brightest stars are also the “cornerstones” for the many constellations we have created to help us find our way around the skies. Even in cities, taking the time to get to learn the constellations is a rewarding activity that can form the basis for more intensive examinations if you find clearer skies.