How many planets do we have?
There are 9 planets in the space known as
mercury,venus,earth,mars,jupiter,saturn,uranum,neptune,pluto. There
used to be 9 planets. But the International Astronomical Union
discovered Eris, beyond Pluto which was a few hundred kilometers
larger than Pluto. Then there could have been 10 planets. So the
IAU came up with three 'conditions' to be a planet: - they need to
orbit the Sun - they need to have enough gravity to pull themselves
into a ball - they need to have cleared out all other objects from
their orbit. Although Pluto orbits the Sun, and has pulled itself
into a sphere, Pluto cannot clear other celestial debris from its
orbit. Earth is more than 1 million times more bigger than all the
other material in its orbit combined, while Pluto is just a tiny
fraction of the rest of the icy material around it. The IAU decided
to name Pluto and Eris as dwarf planets. Asteroid Ceres meets those
requirements, so it is also classified as a dwrf planet. Summing
up; there are currently 8 planets and 3 dwarf planets in our Solar
system