Did you know there might be a hidden planet in our solar system? We usually count eight planets, starting from the closest to the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. But some scientists believe there could be a ninth planet, sometimes called Planet Nine.
This mystery planet might be orbiting the Sun far beyond Neptune, in a place called the Kuiper Belt. The Kuiper Belt is a zone filled with icy objects.
Astronomers in Japan, along with the country’s National Astronomical Observatory, have been studying how things in the Kuiper Belt move. They noticed something interesting. The behaviour of some objects there suggests there might be a big planet hiding in the Kuiper Belt.
This new planet could be about three times bigger than Earth, but it’s incredibly cold, so it wouldn’t support life as we know it.
The discovery of a possible planet near the Kuiper Belt is exciting because it could mean there are more planets yet to be found in our solar system.
A long time ago, Pluto used to be considered the ninth planet, but in 2006, scientists decided to call it a dwarf planet because it’s much smaller than the other eight.