An international team of scientists led by Jian Li of Nanjing University in China may have discovered the reason behind the numerical asymmetry of Jupiter’s Trojan asteroid groups. Each of them is made up of more than 10,000 asteroids, which accompany the planet throughout its orbit around the Sun.
- What is a Trojan asteroid?
- Why is discovering yet another Trojan asteroid near Earth important?
These asteroids lie at Lagrange points 4 and 5, which divides them into two groups: those that go ahead of Jupiter in its orbit belong to L4, and those that stay behind, to L5. For decades, scientists have observed that there are many more asteroids in L4 than in L5, but they didn’t understand why.
To investigate the difference, the scientists worked with a model that simulates the orbital evolution of Jupiter, coming from the orbital instabilities of the planets in the “infancy” of the Solar System. The instabilities caused the gas giant to quickly migrate away from the Sun – and, for the authors, this may have caused changes in the stability of the asteroids.
So, in the new study, the authors propose a mechanism that might explain the numerical difference. “We propose that outward migration (relative to distance from the Sun) from Jupiter may distort the configuration of Trojan groups, resulting in more stable orbits of L4 than L5,” said Li.
According to him, this mechanism temporarily induced different paths for the two groups of asteroids, which is perhaps a new — and natural — explanation for the difference between the groups. In the future, new models may expand the work to include other aspects of the evolution of the Solar System, bringing greater precision to the results.
The article with the results of the study was published in the journal Astronomy & Astrophysics.
Source: Astronomy & Astrophysics; Via: New York University