People are still extremely curious about the evolution of the universe and we still know so little. By researching creation of other planets we may find out more about ours. An international team of researchers used a telescope in the Canary Islands and an instrument called a spectrograph to estimate masses of four planets in a distant star system. This helped them make a discovery about a massive planet collision that led to the formation of an iron-rich planet.
Although you may think that in the vast space of the universe there are thousands of observable planet collisions, this is actually the first evidence found of an impact taking place between planets outside our Solar System. And the iron-rich planet, which formed after collision between two distant worlds, is actually nearly ten times as heavy as Earth. Scientists used a spectrograph to measure precise shifts in wavelengths of light, which enabled them to estimate masses of these planets in the distant star system. They found that while the size of two planets is the same, one is much heavier – it must have a much larger iron core.
The heavier planet, known as Kepler-107c, must have been larger some time ago, but the collision with another planet probably stripped its outside layers. The hypothesis that Kepler-107c used to be much larger can be confirmed by looking at its core, which constitutes around 70 % of the mass of the planet. Meanwhile a very similar Kepler-107b has a core, which accounts only for 30 % of its mass. Scientists estimate that the collision might have happened when the Solar system was still in its early stages. And our planet had its own collisions as well – previous studies suggest that the Moon may have formed following a collision between Earth and a Mars-sized planet around 4.5 billion years ago.
Collisions between different worlds might not have been as rare as previously believed. In fact, they may occur in planetary systems across the Galaxy. However, this is the first time evidences of such event were found outside of the Solar system. Professor Ken Rice, one of the authors of the study, said: “The diversity of planets found outside our Solar System is fascinating. We can use this diversity to better understand how planets form and evolve”.
We still don’t exactly understand formation of different planets. Hopefully, methods tested and improved during studies like this will lead to new discoveries. Understanding how different planets form will eventually provide a better idea how our own planet came to be.
Source: University of Edinburgh