Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

Planet Nine is a hypothesized massive planet, first proposed in 2014, that is speculated to orbit far out in the solar system. It has not been detected formally. Instead, astronomers have inferred its presence from perceived perturbations of the orbits of some Trans-Neptunian Objects (TNOs). The planet is estimated to be 2 to 4 times the radius, and about ten times the mass of the Earth. The best candidate yet for the elusive Planet Nine has been spotted in two deep infrared surveys taken 23 years apart. If this mystery object really is Planet Nine, it would have a mass greater than Neptune, and currently be about 700 times farther from the sun than Earth is. The possibility of additional planets in our solar system has been proposed many times, going under names such as "Planet X," because experts thought the concept of an extra planet in our vicinity of the cosmos could explain a perceived regularity in mass extinctions on Earth. Perhaps, they said, the periodic influx of comets th ... Read full article.