Pluto, once considered the ninth planet of our solar system, has been a topic of intrigue since its reclassification as a dwarf planet. Recent observations suggest that its atmosphere is expanding, ...

Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. A close up of Pluto's ...

When 10-year-old Kaela Polkinghorn asked NASA to make Pluto a planet again, she never expected the agency's top official to ...

NASA explains Pluto's newly discovered "blue sky" and whether or not potential astronauts could ever witness an Earth-like sunrise. The New Horizons space probe sent back its first color images of ...

The New Horizons mission to Pluto isn’t rewriting the textbooks, says NASA spokesman Dwayne Brown. “It is writing the textbooks,” he said, as he closed a Friday press briefing with mission scientists.