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The New Horizons spacecraft, which made headlines when it flew past Pluto last July, may have captured images of clouds hovering above the dwarf planet’s surface. Clouds would indicate a richer atmospheric diversity than initially thought, which may renew calls to reclassify Pluto as a planet. It was demoted to a dwarf planet in 2006. “One way to think of it is that clouds are discrete features, hazes widespread,” said Alan Stern, who heads up the New Horizons mission. Stern said this meant Pluto passed what he called the “Star Trek” test, which he has described as siding with Captain Kirk over Spock—“look at it and make the most obvious call.”