Study suggests rogue interstellar visitor may have shaped our solar system

The research team's simulations indicate a 1 in 100 chance that an interstellar visitor could produce the orbits we see today.

 Oumuamua. An illustration. (photo credit: DLR_next is licensed under CC BY-NC-SA 2.0. Via Flickr)
Oumuamua. An illustration.
(photo credit: DLR_next is licensed under CC BY-NC-SA 2.0. Via Flickr)

New research suggests that the Solar System may have captured a rogue planet, leading to changes in the existing orbits of the planets. The study, conducted by Edward Belbruno from Yeshiva University and former NASA employee James Green, was published in the journal Celestial Mechanics and Dynamical Astronomy.

Traditional models predict that Jupiter, Saturn, Uranus, and Neptune should have nearly circular and flat orbits. However, Universe Today reports that their moderate tilts and slightly elongated paths could be the result of a one-time cosmic flyby by a massive object estimated to be between 2 and 50 times the mass of Jupiter. This new theoretical perspective proposes that such an object passing through the Solar System could be responsible for changes in planetary orbits.

The research, which is still to be peer-reviewed, argues that current theories do not clearly explain the nature of the orbits of gas giant planets like Saturn, Neptune, and Jupiter, particularly regarding their eccentricity, as reported by Science Alert. The researchers developed a metric to compare how closely simulated orbits align with the actual orbits of the giant planets. Their findings suggest that a close encounter with a substellar object provides a plausible explanation for the Solar System’s current configuration, according to The Independent.

According to Universe Today, the research team's simulations indicate a one in a hundred chance that an interstellar visitor could produce the orbits we see today, which is far better than those provided by other theories. "We demonstrate a single encounter with a 2-50 Jupiter-mass object, passing through the solar system at a perihelion distance less than 20 AU and a hyperbolic excess velocity less than 6 km per second, can excite the giant planets' eccentricities and mutual inclinations to values comparable to those observed," the researchers noted, as reported by The Independent.

Over time, as planets grew, interactions within the protoplanetary disk caused orbital migrations, with planets moving both inward and outward, influenced by interactions with neighboring planets and forces from the Sun, according to Science Alert. However, these interactions may not fully explain the current orbital properties of the planets. The evolution of planetary orbits is a complex process, influenced by interactions within the protoplanetary disk and the potential impact of rogue planets, as reported by Scienze Notizie.

The visits of interstellar comets 'Oumuamua' in 2017 and '2I/Borisov' in 2019 proved the existence of such interstellar celestial bodies, according to The Independent. 'Oumuamua was the first confirmed interstellar visitor to the Solar System and has generated great interest in the scientific community, as reported by Universe Today.

Scientists suggest that the number of rogue planets in the galaxy may exceed the number of stars. Occasional encounters with such rogue planets could have played a significant role in shaping not just our Solar System but planetary systems across the galaxy, as reported by India Today.

The study also suggests exploring the effects that an interstellar object flyby could have had on rocky terrestrial planets like Earth and Mars, according to The Independent.

In the area within a 6 parsec radius of the Solar System, there are 131 stars and brown dwarfs. Within the next 50,000 years, six of these stars are expected to make close passes to Earth. During these close passes, objects breaking away from the Oort Cloud may head towards the inner Solar System, further reinforcing the effects of rogue planets.

This article was written in collaboration with generative AI company Alchemiq