Migration Mystery Revealed: Scientists' Observation Gave Answers To A Question Asked Centuries Ago

A distant star called Kepler-223 has four gas giant planets that orbit close in to their sun. It's not that different from our own Solar System today, where planets are far away from each other. This made experts wonder if Kepler-223 was how the Solar System was a long time ago.

A new study that observed the Kepler space telescope implies that indeed Kepler-223 was like our Solar System once upon a time. Perhaps Jupiter, Saturn, Uranus and Neptune were created close in to the sun. As time passed, each planet's gravity worked together and helped them pull away from the disc of gas and dust surrounding the Sun. As soon as the giant planets cleared, this gave room for the smaller planets to live near the sun today: Mercury, Venus, Earth and Mars.

"Exactly how and where planets form is an outstanding question in planetary science," said lead author Sean Mills, a graduate student in astronomy and astrophysics at the University of Chicago, in a statement. "Our work essentially tests a model for planet formation for a type of planet we don't have in our solar system." Discovery News reported that the new study came from a combination of data from Kepler which showed how the four planets affect each other's movements and block light from the star, and simulations of how planets migrate.

However, there were some differences from our own Solar System. Kepler-223 is older (4.6 billion years) meaning that its planets have stayed in place much longer than planets in our Solar System, if they did migrate. However, there were also some interesting facts that were found about this system.

News Yac said that the four planets are in resonance with each other, which means that they orbit in a simple ratio to each other. This is the first time for experts to see four planets in resonance. "These resonances are extremely fragile," said study co-author Daniel Fabrycky, an assistant professor of astronomy and astrophysics at the University of Chicago, in the same statement. "If bodies were flying around and hitting each other, then they would have dislodged the planets from the resonance."

With that said, scientist can conclude that maybe in our own solar system, the four gas giants were in resonance but then were thrown into new orbits over time after hitting asteroids, planets in formation and other debris in the inner part of the Solar System.

One interesting mystery, if that is indeed that case, is how is it possible that there was so much debris in our Solar System coming in between, but Kepler-223 stayed stable for much longer.