There Might Be An “Earth-Sized Planet” Hiding In The Solar System
There may be an undiscovered Earth-like planet lurking within the solar system, according to a team of astronomers looking at the movement of objects in the Kuiper Belt.
Finding planets is no simple task, now that we’ve found the ones like Jupiter which were helpful enough to be fairly visible from Earth. When looking for exoplanets (planets outside of our solar system), we are able to look for dips in light as they pass in front of their parent star. It’s not quite a doddle, but we have discovered 5,502. Not bad, considering we only found our first in 1992.
Discovering objects in our own solar system is a little more complicated, and involves finding where to look by observing the movement of other objects. Neptune was discovered after astronomer and mathematician Urbain Le Verrier noticed a difference between the observed orbit of Uranus and the way Newtonian physics predicted its orbit to be. He calculated that the orbit could be explained by the gravitational influence of a planet beyond Uranus. Sure enough, when German astronomer Johann Gottfried Galle checked where Le Verrier said the planet should be, he found Neptune.
More at https://www.iflscience.com/there-might-be-an-earth-sized-planet-hiding-in-the-solar-system-70527
