Caltech Researchers Find Evidence of So-Called ‘Planet Nine’

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

Astronomers say they’ve found evidence that our solar system may hold another giant planet, hidden in the dark, distant badlands far beyond Neptune’s orbit.

So-called Planet Nine is pictured in the center, between Earth (left) and Neptune (right). Neptune is about 17 times Earth’s mass, and Planet Nine is believed to be 10 times Earth’s mass, according to Caltech researchers. (Credit: Caltech)

So-called Planet Nine is pictured in the center, between Earth (left) and Neptune (right). Neptune is about 17 times Earth’s mass, and Planet Nine is believed to be 10 times Earth’s mass, according to Caltech researchers. (Credit: Caltech)

This so-called Planet Nine, described in the Astronomical Journal, would likely have roughly 10 times the mass of Earth and circle the sun in 10,000 to 20,000 Earth years. Neptune, the farthest known planet today, makes its round trip in 165 years.

If it is found to exist by powerful telescopes on Earth, Planet Nine would rewrite our definition of the solar system and help solve some mysteries about its violent past.

Scientists have been wondering whether a "Planet X" exists in the dim regions far beyond the known planets, but it has remained largely speculative. Scientists and layfolk alike have had to content themselves with just eight planets, cut down from nine after Pluto was demoted to dwarf in 2006.

Click here to read the full story on LATimes.com.

Notice: you are using an outdated browser. Microsoft does not recommend using IE as your default browser. Some features on this website, like video and images, might not work properly. For the best experience, please upgrade your browser.