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Giant Storm
Featured on January 19, 2017
A sunspot forms a dark blotch on the Sun in this recent image from ALMA, a set of telescopes in Chile that look at the universe in millimeter and submillimeter wavelengths, a portion of the radio spectrum. Sunspots are relatively cool magnetic storms on the Sun's surface. The number of spots waxes and wanes on a roughly 11-year cycle. The Sun is currently on the downward slope of one such cycle, so few sunspots have been observed in recent years. This spot is roughly twice the diameter of Earth. [ALMA (ESO/NAOJ/NRAO)]
