Emily Chan
For a while, Pluto was considered the ninth planet in our solar system, but in 2006, it was reclassified as a dwarf planet because it did not meet all the criteria that are used by the International Astronomical Union to define a full-sized planet.
Now, astronomers may be on the verge of discovering a ninth planet—not Pluto. The possible ninth world has been nicknamed “Planet Nine.”
The hunt for Planet Nine has persisted for nearly a decade. It’s been so hard to detect because of how far away it is from the sun.
But with the opening of the Vera C. Rubin Observatory in Chile next year, scientists may just be able to spot the potential ninth planet or dismiss the idea of it for good.
Aside from the now-downgraded Pluto, no other planets beyond Neptune or the Kuiper Belt have been found.
The Kuiper Belt is a massive ring of asteroids, comets, and dwarf planets that orbit the sun beyond Neptune. As time went on, it was looking more and more unlikely that a ninth planet existed.
However, in 2004, scientists discovered that a dwarf planet called Sedna, which was located past the Kuiper Belt, had an unusual orbit around the sun.
This indicated that another large mass out there in the solar system was gravitationally pulling it. In 2014, an object in the Kuiper Belt with a similar orbit was found. Afterward, four others were detected as well.
The findings have led scientists to the conclusion that an unknown planet was the cause of these strange orbits.
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