The head of NASA says maybe Pluto is a planet after all. He is wrong because Pluto is part of the rest of the solar system ...

Add Yahoo as a preferred source to see more of our stories on Google. Guests visting the Lowell Observatory in Flagstaff, Arizona during the I Heart Pluto Festival gaze at celestial objects from the ...

Two decades ago, the International Astronomical Union—which defines and names celestial bodies—redefined the criteria for being a planet, putting Pluto into the new category of dwarf planet ...

Pluto was downgraded from a planet to a dwarf planet in 2006 by the International Astronomical Union. The main reason for Pluto's demotion is that it's not able to "clear its orbit of debris." Other ...

NASA Administrator Jared Isaacman wants to put an end to a decades-long debate among scientists. Is Pluto a planet or not? Isaacman says it should be — but it hasn’t been one for 20 years. That’s ...

Cara dreams of becoming a NASA astronaut and "visit all the main planets including Pluto." But in the meantime, she told NASA, "you need to fix this problem for me." Though not likely to result in a ...

Should Pluto be a bona fide planet again? NASA is working to "revisit the discussion" on Pluto's planethood status, according to agency chief Jared Isaacman.

President Donald Trump may be one step closer to making Pluto great again. NASA Administrator Jared Isaacman endorsed the idea of Trump making Pluto a planet again in an exclusive interview with the ...

In 2006, a vote by the International Astronomical Union determined that Pluto was no longer a planet. The decision sparked a heated public debate, and many planetary scientists disagreed with kicking ...