In 1920, astronomers Harlow Shapley and Heber Curtis held a Great Debate. Shapley argued that the spiral nebulae were small ...

After the storms, a brilliant star-filled night sky appeared on April 19 ... the dancing glow of an aurora colored the Milky Way, stretching all the way to the zenith. The curtains of ...

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From planets and constellations, to eclipses and the Aurora Borealis, here's what to look for in the sky this spring ...