What is a planet? What causes a world to be a planet, a dwarf planet or an exoplanet? Since the late 1980s, researchers have discovered nearly 5,000 planetary bodies orbiting stars other than the sun. Now, scientists have defined what should be called a planet and what shouldn't be.
The current official definition of a planet applies only to bodies in our solar system. However, this has created a "definition limbo" for the newly discovered bodies outside our solar system. Now, researchers propose to extend the planet definition to all planetary systems.
The new approach would actually only require estimates of the star's mass and the planet's mass and orbital period. All of these things can easily be obtained with Earth- or space-based telescopes. According to the criteria, all eight planets in our solar system and all classifiable exoplanets would be confirmed as planets.To read more, click here.