An interesting study found that Uranus’s extreme tilt is the result of satellites such as Saturn’s rings.
An international research group that includes the Sorbonne University in France and the University of Pisa in Italy published an article on the 14th and argued that Uranus’s axis of rotation, which was almost on its side, was caused by a satellite giant.
The rotation axis of the solar system planet Uranus is 97.77 degrees. Given that the tilt of the rotation axis of the other planets in the solar system is about 30 degrees, this is quite unusual.
The hypothesis that has been constantly advanced as to why Uranus’ axis of rotation is so inclined is the “giant impact theory”. As evidence that it has been found on other planets, the giant impact theory is a factor in the tilt of the planet’s rotation axis.
But the biggest weakness of this hypothesis is the lack of clear evidence and it cannot be verified due to the disappearance of the colliding satellite. For Neptune, which has an internal structure and atmospheric composition similar to Uranus, this hypothesis has already been rejected and it is difficult to vaguely apply the giant impact theory to Uranus because its axis of rotation is about 28 degrees.
Recently, theories have emerged that the axes of rotation of Jupiter and Saturn, which are not very inclined, moved several times a billion years ago and reached the present. Scientists say this depends on the tidal power of the giant moons of Jupiter and Saturn.
The research team believes this hypothesis is worth testing on Uranus. The research team, which prepared a simulation of the satellite’s tilt axis, analyzed the interaction between the mother and the moon over a period of over 4 billion years, assuming the presence of Uranus satellites at different distances and masses. .
Consequently, if there were a satellite with a mass of 0.044% of Uranus (0.64% of the Earth, 52% of the Moon), the axis of rotation of Uranus would simply tilt more than 80 degrees in millions of years. However, the mass has been calculated to be up to four times the mass of the 27 moons currently orbiting Uranus, including Titania.
A research team official said: “When the tilt of the rotation axis reaches this level, the change in the tilt of the Moon’s orbit and Uranus axis becomes unstable.
In other words, the research team concluded that the tilt of Uranus’s rotation axis was almost permanently constant in case it fell to one side when the giant satellite that was interacting with its mother collided and disappeared. . The absence of satellites is also explained in this case. Assuming that the giant satellite has the mass derived from the simulation and that the radius of the orbit varies in a range greater than 10 times the radius of Uranus, this scenario has a probability of more than 80%.
The research team recognized that the hypothesis that a giant moon collided with Uranus cannot be directly verified, as well as the theory of a giant impact. However, we plan to see if Uranus’ current satellites can serve as evidence in future simulations.
Journalist Jeong Ian Angle @ sputnik.kr
