Why is Uranus Spinning on its Side?

It is known about Uranus that it is spinning on its side, instead of being upright to its axis. But how come that?

Although we have limited information about Uranus, it is regarded as the most mysterious planet of our solar system. The most obvious mystery of Uranus is the fact that it is spinning on its side. The spin axes of all the other planets are approximately at right angles to their orbits around the Sun. On the other hand, the spinning axis of Uranus is tilted by almost 90 degrees. Consequently, the north pole of the planet points directly towards the Sun in its summer. Similarly, it has vertical rings and moons whereas Jupiter, Saturn, and Neptune have horizontal sets of rings around them.

Why is Uranus Spinning on its Side?

Scientists are pretty determined to understand the reason for this odd behavior of Uranus and recent research might have offered a clue to solve this riddle. It is common knowledge that our solar system was an extremely violent part of space in its early days. Massive impacts between protoplanets eventually led to the worlds that we see today. A lot of scientists believe that Uranus is spinning on its side due to a cataclysmic collision. The basic purpose of the study was to discover the possible events that could have made Uranus spin on its side.

The researching team used computer simulations and a powerful supercomputer to model the colliding planets. Millions of lumps of planetary material were fed to the system alongside the equations that describe various related concepts of Physics, including material pressure work and gravity. It enabled the simulation to calculate the evolution of particles as they smashed into one another. The program was good enough to even comprehend the results of a humungous impact. The fact that the researchers were in complete control of the simulations offered them the opportunity to test different scenarios.

Strange Spin of Uranus

The simulations showed that a body twice as big as the Earth could make a young Uranus spin on its side by merging with the planet. In addition to that, the material of that body spread out in a thin, hot shell underneath the atmosphere of Uranus. As a result, the mixing of material inside Uranus was inhibited due to which the heat from its formation was trapped deep inside the planet. What makes this model even more fitting is the cold exterior of the ice giant. Despite the fact that thermal evolution is much more complex than that, the simulations prove that a massive collision can reshape a planet inside out.

Bigger Picture

The significance of this finding increases many times when we consider the universal benefits of this research. Recent discoveries have revealed that the most common type of exoplanets is quite similar to the two ice giants (Uranus and Neptune) of our solar system. Therefore, all the data that we have about the evolution of these planets adds to our understanding of their distant cousins. The factor of extraterrestrial life makes this study even more critical for future research.

The fate of an atmosphere after a massive impact is a vital factor for harboring extraterrestrial life. The simulations showed that most of the atmosphere was removed by the initial clash while the subsequent violent bulging of the planet eliminated what remained behind. Although such a place is unlikely to host any kind of life, the presence of rocky material (from the core of the colliding body) in the atmosphere of an exoplanet can give us some useful insights about similar impacts.

Future Mission

Uranus still has a lot of secrets and we need to keep digging in to explore more and more about this mysterious planet of our solar system. Similarly, our knowledge of planetary impacts is far from complete. Numerous people have already demanded a new mission to Uranus and Neptune in order to study their moons, rings, strange magnetic fields, and the basic composition of these ice giants. Jacob Kegerreis, a Ph.D. student at Durham University who was also a part of the researching team, mentioned that a combination of theoretical models and computer simulations will allow us to understand the myriad planets that fill our universe.