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How can something REALLY LARGE be hidden from sight? If it’s an object in space, astronomers can know it’s there from the reactions of other stars and planets, even if they can’t see it. They have evidence that either GIANT brown dwarf ("cold") star or a HUGE gas giant planet is at the outermost reaches of our solar system, far beyond Pluto. Astronomers think it’s 4 times as big as Jupiter and have even named it: Tyche. They even think it may be responsible for the mass extinctions that occur at regular intervals on Earth.
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