Scientists have made an unexpected discovery concerning the Earth and other planets. According to this, planets may have once been flat.
Research led by astrophysicists Adam Fenton and Dimitris Stamatellos has revealed an unexpected discovery in the formation process of planets. New simulations suggest that large planets begin their lives not as a sphere like Earth, but more like a saucer or a flat disk.
Not Earth, but Jupiter
Simulation experiments suggest that large planets that form far from their host stars begin their lives not as a sphere, but as an oblate spheroid. As these protoplanets rotate, they gradually draw in material and eventually, as with Jupiter, they first take on a round shape, like a saucer.
Stamatellos: “We’ve been studying planet formation for a long time, but we’ve never thought of controlling the shape of planets in simulations before. We always assumed they were spherical,” says Stamatellos. Although many planets have been found in the Milky Way, more than 5,500 have been confirmed so far. How they formed is not entirely clear.
When a star is born, it is formed from a cluster in a huge, dense cloud of gas and dust in space, which collapses under gravity and begins to spin. The material around it forms a disk that rolls into the baby star and feeds its growth.
So how does the material in the disk come together?
For smaller terrestrial planets such as Earth, Venus, Mars and Mercury, scientists think they are built gradually by piling up chunks of rock that stick together and accumulate until you get a planet.
For larger gas giants, scientists believe that something called disk instability can occur. This is when the rapidly cooling disk around the star breaks into fragments that condense under gravity and turn into planets.
Fenton wanted to better understand the process of disk instability planet formation, so he designed and ran complex simulations, varying different aspects of the process, such as gas density, temperature and the speed of the disk.
“It was an extremely challenging computational project requiring half a million CPU hours at the UK’s DiRAC [Distributed Research Using Advanced Computing] High Performance Computing Facility, but the results were incredible and well worth the effort!” says Fenton.
The simulation says it’s “flat”
These results revealed that gas giant protoplanets first form a flat shape as they spin, which makes sense given the centrifugal force and the fact that the protoplanet is still a relatively loose collection of matter at that stage.
Even the well-formed and much more compact planets of the Solar System have centrifugal bulges around their equator. The simulation also shows that material is deposited on the growing protoplanet predominantly at the poles rather than at the equator.
Research shows that the properties of a protoplanet embedded in a stellar disk can change depending on the viewing angle. From the side, its flat shape is more obvious, but from above it is easy to mistake the round shape for a sphere.
Researchers say we’re getting better and better at detecting these emerging planets, so it’s important to grasp how to interpret what we’re looking at.
So what do you think about this issue? You can write in the comments section below.
