The Solar System may have had an extra planet once, an ice object kicked out of its orbit, but whose existence contributed to today's planetary orbits.

The planets were born out of a dust and gas cloud circling the young planet, with galaxies developing out of the aggregation of clumps of matter.

The giant planets' orbits were once believed to be close-packed and circular, but gravitational forces changed them to today's configurations.

This structure is known to be 'particularly peculiar,' and scholars have long tried to understand its origins.

Thousands of simulations of how the orbit of the solar system's planets may have developed over time were run by US researchers to find the one that better describes their current condition.

Through this, the team indicates that 'eccentric' or oval-shaped orbits and varying orbital durations started with Jupiter and Saturn than commonly assumed.

Ice Giant Between The Planets

The researchers also believe that the gravitational pull of a mysterious lost object, an ice giant that once lay between Saturn and Uranus, impacted the 'ice giant' planets, Uranus and Neptune.

'We now know that there are thousands of planetary systems in our Milky Way galaxy alone,' said paper author and planetary scientist Matt Clement of the Carnegie Institution for Science in Washington DC.

'But it turns out that the arrangement of planets in our Solar System is highly unusual, so we are using models to reverse engineer and replicate its formative processes,' he added.

'This is a bit like trying to figure out what happened in a car crash after the fact - how fast were the cars going, in what directions, and so on.' 

Dr. Clement and his collaborators performed 6,000 separate models of the Solar System's development in their research, emphasizing Jupiter and Saturn's interaction.

It was assumed that Jupiter completed three maximum revolutions around the Sun in its infancy, with every two carried out by Saturn. Still, research has shown that this beginning structure cannot account for the design of the gas giants today.

Rather, the team's best-fitting model indicates that, instead, with both of those created by Saturn, Jupiter most definitely performed two trips around the universe, contributing to something similar to the solar system design we have today.

Various External Variables

The researchers have concluded that several external variables determined the orbits of Uranus and Neptune.

This includes the Kuiper belt's gravitational effects, the doughnut-shaped ring of frozen artifacts, including Pluto and other dwarf planets and planetoids, as well as the consequence of another universe of ice that was knocked out of its orbit.

'This illustrates that while our planetary system is a bit of an oddball, it has not always been the case,' Dr. Clement explained.

'What's more, now that we have developed this model 's usefulness, we will use it to help us look at the development of our planetary worlds, like ours.'

He also said the method could also be used to 'inform our capacity to search elsewhere for related structures that could have the ability to host life.'

The full research results have been published in the journal Icarus.

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