This week, Comet PANSTARRS will be a naked eye object for observers in the northern hemisphere. But you need to be quick–it is low on the western horizon, close to the sun. If you are too early, the sky is too bright to see it. If you are too late, it will have already set. [...]
Many of the patterns of astronomy are so regular that we quite literally set our clocks by them. Our notions of time are tied to the regular cycles of day and night and of the yearly seasons, all of which have their origins in the rotation of the earth on its axis and in the [...]
