A survey involving 909 planets orbiting 355 stars has revealed that most exoplanets within a system tend to have similar sizes and orbit their stars in an orderly fashion. Most of the planets were between 1 thousand and 4 thousand light-years from Earth.
This data obtained by the Kepler Space Telescope may suggest that many planetary systems have a different formation history than our solar system, scientists said. The team managed to measure each planet’s size by tracking them when they passed in front of their host stars. Bodies passing in front of a star dim its light, which allows researchers to estimate the distance between the planet and its star.
Once they used a statistical analysis of these celestial bodies, researchers realized that the exoplanets tended to have the same sizes. If a planet was big then next planet was also about the same size and this applied to smaller planets as well.
“The planets in a system tend to be the same size and regularly spaced, like peas in a pod, said Lauren Weiss, an astrophysicist at the Université de Montréal and lead author of the study @ These patterns would not occur if the planet sizes were drawn at random”.
This would mean that knowing the size of one planet or establishing its orbital distance from its star would allow astronomers to accurately predict most of the sizes and other properties of their neighbors.
More so, the researchers discovered that planetary systems with some size variation have smaller planets closer to the star. This was especially true if the planet had a short orbital period, said the researchers.
According to the study, even orbital spacing and similar planet sizes could have implications to how most planetary system form. The most accepted theory states that young stars form a protoplanetary disk composed mainly of debris that coalesces and accretes into planets.
The study was published in The Astronomical Journal.
Image Source: WikipediaCommons