Uranus’ Tilt Caused By ‘Cataclysmic’ Collision From 4 Billion Years Ago

Igor FilonenkoiStock

While “The Big Bang” might conjure up images of the creation of our universe (or worse, images from a tired and stale CBS sitcom), it seems an entirely different ‘big bang’ might account for the evolution of Uranus, the most awkwardly named of planets.

As reported by Phys.org, it seems like Uranus collided with a massive celestial object, one that was roughly twice the size of Earth. This collision would have occurred during the initial formation of our solar system, approximately four billion years ago. The object in question would have most likely been a protoplanet made up of ice and rock.

This discovery came as a result of an investigation into how Uranus ended up with a sideways axial tilt. A team comprised of experts from around the world was led by astronomers from Durham University. To get an idea of how the planet was shaped and evolved, the team ran extensive computer simulations of various collisions, to see how they would have impacted Uranus. These simulations confirmed a previous study, which suggested that Uranus’ tilt was originally caused by a collision.

Research also indicated that the debris from the colliding proto-planet could have formed a thin shell along the edge Uranus’ ice layer, in turn trapping any thermal energy from the planet’s inner core. This could help explain the cold temperatures along the planet’s outer atmosphere, which hover at around -357 degrees Fahrenheit (-216 degrees Celsius).

The findings from this research have been published in The Astrophysical Journal. Jacob Kegerreis, lead author of the paper and researcher at Durham University’s Institute for Computational Cosmology, explains how the collision impacted the evolution of Uranus:

“Uranus spins on its side, with its axis pointing almost at right angles to those of all the other planets in the solar system. This was almost certainly caused by a giant impact, but we know very little about how this actually happened and how else such a violent event affected the planet.”

“Our findings confirm that the most likely outcome was that the young Uranus was involved in a cataclysmic collision with an object twice the mass of Earth, if not larger, knocking it on to its side and setting in process the events that helped create the planet we see today.”

The research could also help to provide an explanation for how Uranus’ planetary rings were formed. The particles that make up said rings vary in size, from mere micrometers to fractions of a meter.