Question

Why is Pluto so small?

Answer 1

Pluto is not very small it is also big it is far away from earth that's why it looks so small

Answer 2

Pluto is smaller compared to other planets.

When the Big Bang took place,maybe the small amount of hot matter and debris of explosion shattered .Eventually after several years it cooled down and hence formed Pluto.

Earth is also formed like that. But maybe Pluto had a small mass from its beginning.That was its destiny.

Thanks.