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A rough start to the Solar System

The Solar System might have had a rougher start than previously thought. From ScienceNOW: According to the prevailing hypothesis, the solar system condensed out of an immense disk of gas and dust about 4.6 billion…


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GraphDark

With GraphDark, a very simple program, you can draw graphs showing you when Sun, Moon and planets rise and set. These graphs are well known from astronomy magazines like Sky & Telescope.