A new analysis reveals that the Sun has the potential to “capture” interstellar objects much larger than what we have observed so far.
In an article published in the scientific journal Celestial Mechanics and Dynamical Astronomy, two American astrophysicists outlined how the Sun could become a formidable kidnapper.
Over the past few years, humanity has detected two interstellar objects: Oumuamua and the comet 2I/Borisov.
While many theories suggest they could have been sent by extraterrestrials, most scientists believe these are wandering objects temporarily captured by our Solar System.
Establishing a new model, researcher Edward Belbruno from Yeshiva University and former NASA Chief Scientist James Green investigated the extent of the Sun’s formidable capture capabilities.
A wandering planet, a potential candidate for being captured by the Sun into the system – (Graphic: NASA/JPL-CALTECH).
The authors analyzed the phase space of the Solar System—a mathematical model that describes the state of a dynamical system like our star system.
The phase space of the Solar System contains capture points where interstellar objects can find themselves gravitationally bound to the Sun. There are two types of capture: weak and permanent.
Objects like Oumuamua and 2I/Borisov may only be captured in a “weak” manner, meaning they enter a region where an object can temporarily be pulled into a semi-stable orbit. These points are usually where the outer edges of the gravitational boundaries of objects intersect.
On the other hand, permanent capture points are regions where a kidnapped object can be pulled in forever or for an extremely long time, with angular momentum and energy allowing it to maintain a stable orbit.
The study also indicates that not only small objects, but our Sun has the ability to capture an entire planet.
Within a radius of 6 parsecs around the Sun, there are 131 stars and brown dwarfs, not to mention several wandering planets that have been ejected from their star systems due to unfortunate collisions.
According to new estimates, 6 of those stars will pass close to us within 50,000 light-years.
They will cause encounters in the Oort Cloud surrounding the Solar System, potentially pushing several objects in this area into the heliosphere, or even those wandering planets unfortunate enough to linger there.
The researchers also calculated that the phase space of the Solar System might contain “holes,” facilitating the aforementioned incursions. These holes are located 3.81 light-years from the Sun in the direction of the galactic center or opposite to it.
In the worst-case scenario, if an entire planet enters the Solar System, it could disrupt the other planets and potentially alter the course of life on Earth.
However, this risk is likely to occur only in an extremely distant future.
Nonetheless, the discovery of the Sun’s potential for “kidnapping” provides a foundation for observatories to search for interstellar objects approaching us in the near future, representing a great opportunity for humanity to examine a specimen from another star system.
