9th Planet Bigger Than Earth Could Exist In Far Solar System, Scientists Say

Two planetary scientists said Wednesday that a ninth planet could be orbiting the Sun in the outer reaches of our solar system.

The research, published Wednesday in The Astronomical Journal, said that strong evidence exists for a planet about 10 times as massive as Earth orbiting the Sun 700 times as far away.

The discovery of such a planet would upend our understanding of the solar system yet again.

After Pluto was discovered in 1930, it became the solar system’s ninth planet and held that designation for 76 years before its demotion.

Scientists now recognize eight official “planets,” with several dwarf planets orbiting in both the asteroid belt between Mars and Jupiter and the Kuiper Belt beyond Neptune.

The size of the planet suggested in Wednesday’s study would be more than enough to qualify it as the new ninth planet.

One of the co-authors of the paper is Michael E. Brown, the scientist largely responsible for Pluto’s drop from planet status almost 10 years ago after discovering other similarly sized objects orbiting nearby.

Brown studies the distant solar system, and while he and co-author Konstantin Batygin did not directly observe this ninth planet, they strongly suggested its existence by looking at the orbits of nearby bodies.

The Kuiper Belt is a region of the Solar System beyond Neptune, where rocks, asteroids and dwarf planets (including Pluto) orbit. But the motion of distant objects in the Kuiper Belt don’t exactly follow the paths you would expect them to on their own.

That’s the basis for Brown’s study, which said that “the existence of such a planet naturally explains” the discrepancies.

• Read the full study suggesting a ninth planet in the solar system here.

Image via European Southern Observatory