Caltech astronomers announced Wednesday they have found evidence of a giant ninth planet that they’ve nicknamed Planet Nine.
Although they haven’t actually seen it, researchers Konstantin Batygin and Mike Brown said they discovered the planet’s existence through mathematical modeling and computer simulations.
“This would be a real ninth planet,” according to Brown, a planetary astronomy professor at the university in Pasadena. “There have only been two true planets discovered since ancient times, and this would be a third. It’s a pretty substantial chunk of our solar system that’s still out there to be found, which is pretty exciting.”
According to Caltech, the planet has a mass about 10 times that of Earth and orbits about 20 times farther from the sun on average than Neptune. Researchers said it would take the planet between 10,000 and 20,000 years to make one full orbit around the sun.
Brown noted that there should not be any doubt whether the object is a planet, unlike Pluto, which lost its planetary status and was instead deemed a dwarf planet.
The reclassification of Pluto lowered our solar system from nine planets to eight, meaning the newly discovered object would raise our planetary neighborhood back to nine.
Brown said Planet Nine has a mass 5,000 times that of Pluto.
“Although we were initially quite skeptical that this planet could exist, as we continued to investigate its orbit and what it would mean for the outer solar system, we become increasingly convinced that it is out there,” said Batygin, an assistant professor of planetary science. “For the first time in over 150 years, there is solid evidence that the solar system’s planetary census is incomplete.”
Brown and his colleagues say they have begun searching the skies for Planet Nine, although only the planet’s rough orbit is known — not the precise location of the planet on that elliptical path.
If the planet happens to be close to the sun during its orbit, Brown says, astronomers should be able to spot it in images captured by previous surveys.
If it is more distant, the world’s largest telescopes — such as the twin 10-meter telescopes at the W. M. Keck Observatory and the Subaru Telescope, all on Mauna Kea in Hawaii — will be required to see it, the professor said.
If, however, Planet Nine is now located anywhere in between, many telescopes have a shot at finding it.
“I would love to find it,” Brown said. “But I’d also be perfectly happy if someone else found it. That is why we’re publishing this paper. We hope that other people are going to get inspired and start searching.”
Brown, known for the role he played in the “demotion” of Pluto from a planet to a dwarf planet added, “All those people who are mad that Pluto is no longer a planet can be thrilled to know that there is a real planet out there still to be found.”
“Now we can go and find this planet and make the solar system have nine planets once again,” he said.
— City News Service