As the only intelligent beings in the Solar System, humans have existed on Earth for 5 million years. </strong Just like their inherent characteristics, despite the passage of generations, humans have always maintained an insatiable curiosity and a relentless desire to explore everything in the universe.
From the geocentric theory to the Big Bang theory, we continuously refresh our understanding of the world around us. However, despite our unprecedented knowledge of the Solar System, there remain many unanswered mysteries.
For instance, when discussing the scope of the Solar System, we consider the size of the Oort Cloud. Yet, even decades later, scientists are still uncertain about the existence of the Oort Cloud. Another example is the unusual movements observed while studying Neptune, which raises the question: Is there a ninth planet in the Solar System beyond Pluto?
In a recent study, some scientists even claimed that the Solar System once had two suns. So, what is happening?
The ninth planet has yet to be found. (Illustrative image).
As children, many of us may have heard the legend of Hou Yi shooting down the suns, where ten suns appeared simultaneously in the sky, causing the earth to nearly wither. Hou Yi shot down nine suns, leaving only one to illuminate the sky.
Legends are legends; if there were truly ten suns, Earth would have collapsed instantly. However, in the real universe, having two or even three suns is quite common. More than 50% of stars in the Milky Way belong to binary or multiple star systems, where some stars orbit each other or a common center of mass. For example, the Alpha Centauri galaxy, the closest to us, belongs to a three-star system.
Current observational results suggest that most star systems typically have more than one parent star. Therefore, theoretically, the Sun could very well have a sibling star. This hypothesis may date back to the 1980s. After a lengthy study, an astronomy enthusiast named Muller first proposed the idea of two suns, inferring that the Sun does indeed have its own companion star.
Subsequently, many scientists began researching this concept. Researchers from Harvard University believe that the early formation of the Solar System should also have been a binary star system, but the other star was much smaller than the Sun and was a red dwarf. However, as the Solar System evolved, that star departed without a clear reason.
Alternatively, it may not have left the Solar System at all, but rather orbits very far from the Sun… The reason we cannot observe it is that its surface temperature is too low and it emits almost no light.
Scientists believe the Sun has a companion star with a meeting cycle of 27 million years. (Illustrative image).
Despite being difficult to observe, scientists are attempting to prove the existence of this companion star through two phenomena.
First, in 1984 and 2010, two teams of paleontologists conducted studies and analyses of extinction cycles and found that over the past 500 million years, the extinction cycle of living organisms is approximately 27 million years. Therefore, they believe that the Sun has a companion star with a meeting cycle of 27 million years.
This companion star would wander through the Oort Cloud every 27 million years, bringing destruction to Earth. Hence, it has been named Nemesis, the ruthless goddess of vengeance in Greek mythology.
After calculations, researchers believe that Nemesis’s perihelion is about 1 light year and its aphelion is 3 light years. When it is at perihelion, it causes gravitational disturbances in the Oort Cloud and the Kuiper Belt. Both locations are reservoirs of comets in the Solar System, and a large number of comets would be ejected from their original orbits and move toward the inner Solar System. This significantly increases the likelihood of Earth being struck by comets, causing periodic mass extinctions on Earth.
There may be a heavier celestial body in the Oort Cloud. (Illustrative image).
The second phenomenon is the unusual orbit of Neptune. Shortly after the discovery of Uranus in the 1820s, astronomer William Herschel observed the orbit of Uranus and found discrepancies between its theoretical position and the position calculated from the total observed positions. Therefore, scientists at the time suspected that another planet with a larger mass was exerting gravitational influence on Uranus, affecting its orbit.
Using Newtonian mechanics, Oban Le Verrier manually calculated the orbit of the eighth planet. After submitting it to the Berlin Observatory for observation, the eighth planet was discovered there: Neptune.
After resolving the issue of Uranus’s orbit, anomalies began to appear in Neptune as well. Additionally, the Kuiper Belt exhibits some unusual clustering phenomena. Celestial bodies are concentrated in certain areas that should be randomly distributed, indicating that there may be a heavier celestial body attracting them.
Pluto has a very small mass and is clearly not the mysterious ninth planet. (Illustrative image).
Thus, scientists want to apply a similar process to calculate the position of the ninth planet. But this time, something went wrong; after discovering Neptune, it took more than 80 years to locate Pluto using telescopes. However, Pluto has a very small mass and is clearly not the mysterious ninth planet.
Consequently, scientists speculate that there may be a heavier celestial body in the Oort Cloud, possibly the Sun’s companion star or the ninth planet. To confirm this, we must reach or observe the Oort Cloud.
However, the Oort Cloud lies in interstellar space at the edge of the Solar System, approximately 1 light year from the Sun, with a maximum radius of 1 light year. This means that reaching the edge of the Oort Cloud requires traversing a distance of two light years, nearly half the distance from the Sun to Proxima Centauri.
Even the farthest Voyager 1 probe would take 300 years to approach the Oort Cloud and 30,000 years to traverse it. Therefore, we can only wait until a faster probe is invented in the future before we can thoroughly search for the mysterious ninth planet in the Oort Cloud.
