Astronomers have been trying to discover evidence that worlds exist around stars other than our Sun since the 19th century.

If the object really is Planet Nine, it would be larger than Neptune and exist 700 times further from the sun than Earth.

A lexa, May the Fourth be with you. For Star Wars Day, May 4, fans may choose to celebrate by watching Star Wars movies, or ...

"If the ultimate result of this story is that the public is more circumspect about future claims of life detection, that's ...

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