What's the Difference Between a Planet and a Dwarf Planet?

Imagine you're playing with toy cars on a big track. A planet is like the car that goes all the way around the track and keeps to its own path. But a dwarf planet is more like a toy car that also goes around the track, but it doesn’t clear out all the other toys in its lane.

Why Does It Matter?

Scientists use this rule, called the IAU definition, to decide if something is a planet or a dwarf planet. That’s why Pluto went from being a planet to a dwarf planet.

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Examples

A planet is like a car that clears its lane on the track. A dwarf planet is like a car still sharing space with other cars.
Pluto used to be a planet, but it didn’t clear out all the other icy rocks in its orbit, so now it’s a dwarf planet.
Earth is a planet because it has cleared most of the space around it, while Ceres is a dwarf planet because it shares its orbital neighborhood with many asteroids.

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Categories: Space · Planets,Dwarf Planets,Solar System