Accretion (astrophysics)

Alright kiddo, imagine a giant round thing floating in space called a star. Now imagine there are smaller things floating around it, like rocks and dust.

Over a really long time, some of these rocks and dust start to clump together. As more and more of these clumps stick together, they become bigger and bigger until they turn into big chunks of rock, called planetesimals.

Now, these planetesimals are still floating around the star, and if they get close enough to each other, they can stick together too. This is called accretion.

It's like if you had a bunch of little Legos and you stacked them on top of each other, eventually you'd have a big tall tower.

So, as these planetesimals keep sticking together, they eventually form planets! This is how our own solar system formed.

Accretion is a really important process in astrophysics because it helps us understand how planets, moons, and other objects in space are formed.