[NTD Times, Beijing, July 27, 2023]You may have learned that there are 9 planets around the sun, or that there are 8 more planets in the solar system after the infamous Pluto demotion. But what if another world lurks in the far outer reaches of our solar system?
A new paper published June 19 in MNRAS Letters suggests that comets may not be the only ones at the outermost edge of the solar system. In fact, astronomers have calculated that there is a 7 percent chance that a planet near Earth is hidden in the “Oort cloud,” the spherical shape of ice and rock that usually resides in comets. Region, so unimaginably large, its edge is tens of thousands of times farther from the sun than the earth is from the sun. About one in every 200 to 3,000 stars may also host such a distant planet, according to the researchers’ computer simulations.
“It’s entirely possible that the solar system could capture such an Oort cloud planet,” said Nathan Kaib, an astronomer at the Planetary Science Institute and a co-author of the new study. These hidden objects are “a class of planets that absolutely should exist, but have received relatively little attention so far,” he added.
If there is a planet in the Oort Cloud, it must be an ice giant. When large planets like Jupiter, Saturn, Uranus or Neptune form, they are born as twins. The problem is that these massive worlds have considerable gravitational pull and, like quarreling siblings, often collide with each other. These pushes can destabilize a young solar system, sometimes causing one of the planets to be kicked out of the system, or exiled to the outer reaches of the solar system, in rather strange orbits.
“The surviving planets have weird orbits, like their scars from violent (collisions),” said lead author Sean Raymond, a researcher at the Astrophysics Laboratory at the University of Bordeaux. This means that not only are exiled Oort cloud planets very far away from their stars, but their orbits would also be elongated, more like the ellipse of a comet than the near-perfect circle that Earth orbits the sun. The great distance makes it hard to see it, and if it does exist, it’s so faint it’s almost invisible, so it’s hard to spot it,” Raymond added.
“If there’s a Neptune-sized planet in our own Oort cloud, chances are we haven’t found it yet,” said MIT astronomer Malena Rice, who was not involved in the work. Agree. “Surprisingly, it is sometimes easier to find planets hundreds of light-years away than backyard planets!”
Against all odds, astronomers have been hunting for decades in the Oort Cloud and, more recently, the Kuiper Belt in hopes of finding the elusive “hypothetical Planet X.” Planet X, also known as Planet Nine, is a Neptune-sized planet thought to orbit 60 billion miles from the sun. Caltech astronomers Mike Brown and Konstantin Batygin deduced from observations of multiple objects in the Kuiper belt that there must be a massive object like Planet X that would separate these The observed objects are guided into the alignments we see, but this theory has not been proven.
Unfortunately, the Oort cloud planet that Raymond and his team found is not the same Planet X that Brown and Batygin have been looking for.
Although the so-called Oort cloud planet is far away and has an extended, bizarre orbit, the similarities end there. “The Oort Cloud planets in our simulations would be much, at least 10 times farther than the predicted orbits of Planet Nine,” Cabe explained.
“Our simulations were unable to place planets in orbits similar to Planet Nine.
So, in the outer reaches of our solar system, there may be not one but two planets waiting to be discovered, along with countless others orbiting different stars. “These results highlight how much remains to be discovered not only in exoplanet systems, but even in our own solar system,” Rice said.
(Reposted from The Epoch Times/Editor in charge: Ye Ping)
