The edge of the solar system is a dark and distant region that we cannot escape from. Even relatively large planets may be easily invisible to us if they are far from the sun’s light.
of Transsolar system object The TNOs we discovered beyond Neptune’s orbit exhibit some unusual clustering behavior that may indicate the existence of hidden worlds. This led scientists to propose the idea of Planet Nine, a large terrestrial planet lurking far beyond the visible range.
Now, two scientists have come up with an alternative explanation. It’s a more modest, Earth-like world located much closer and in a tilted orbit than the disputed planet Nine, which could explain strange behavior caused by the presence of something larger. Thing.
Planetary scientists Patrick Sofia Rikauka of Japan’s Kindai University and Takashi Ito of the National Astronomical Observatory of Japan say that this world, far from the sun and in the icy darkness, has a mass less than three times the mass of Earth, or even more. It’s not about the size. 500 or more astronomical unit From the sun.
“We predict.” those people write“Earth-like planets and several trans-Neptunian objects exist in unusual orbits in the outer solar system, and these may serve as signatures that allow observational verification of putative planetary perturbations.” be.”
The most distant single object we could find in our solar system was 132 astronomical units from the sun when it was discovered. For comparison, Pluto is on average about 40 AU from the Sun.
But beyond Neptune (30 astronomical units from the Sun), there are plenty of icy rocks and dwarf planets stretching as far as the eye can see. This is the Kuiper Belt, and the objects it contains are TNOs.
In recent years, more sensitive telescopes and surveys have allowed us to find far more TNOs than previously identified, allowing scientists to begin to notice patterns.
One of those patterns is clustering. Several groups of TNOs travel en masse on tilted orbits, suggesting that they are being gravitated by something much larger than the small objects detected so far. I am.
In 2016, Caltech astronomers Mike Brown and Konstantin Batygin pointed to a hypothetical Planet Nine as the culprit.This planet is It is believed that It has approximately 6.3 times the mass of Earth and orbits at a distance of over 460 astronomical units.
But they weren’t the first to explain it. Lykawka and his colleague Tadashi Mukai, then at Kobe University, focused on TNO clustering. 2008 Hidden Kuiper Belt Planet Hypothesis.
Now, with more data on what’s out there, Lykawka and Ito have rethought and refined this idea. They discovered properties of a hypothetical planet that could explain some of the peculiarities of the Kuiper belt. Further observations may determine whether they are correct.
“We determined that an Earth-like planet in a remote, inclined orbit could explain three fundamental properties of the distant Kuiper belt: the presence of a significant population of TNOs with exceeding orbits, a significant population of high-inclination objects, and some extreme objects with unusual orbits; those people write.
These Earth-like planets have 1.5 to 3 times the mass of Earth, orbits of 250 to 500 AU at their furthest point from the Sun, and each have an inclination of 30 degrees to the plane of the solar system. .
Its existence could explain the orbits of celestial bodies with inclinations greater than 45 degrees and dwarf planets. sedona, has a very strange and elongated orbit. It may also explain the properties of her group of TNOs, which appear to be associated with Neptune and are often excluded from such studies.
Their discoveries provide verifiable signs of their hypothetical planet. The planet’s gravity will push TNO into cluster populations larger than her 150 AU, but as our techniques and instruments improve, we may be able to find it.
“Learning more about the orbital structure of the distant Kuiper belt could reveal or rule out the existence of hypothetical planets in the outer solar system.” those people write. “The existence of Kuiper belt planets may also impose new constraints on planet formation and dynamical evolution in the trans-Jupiter region.”
This study astronomical journal.