Astrooceanography is a big and difficult word that means studying the oceans on other planets and moons in outer space. It's similar to regular oceanography, which studies the oceans on our own planet Earth, but astrooceanography is all about outer space.
Imagine that instead of living on Earth, you lived on a different planet or moon, like Mars or Europa. Instead of having land and trees and things like that, you might have a big ocean covering the entire surface of your planet or moon. That's why it's important to study the oceans on those other places, so we can learn more about the oceans on different planets and moons.
Astrooceanographers use special tools and telescopes to study the oceans from far away, since they can't just jump into a spaceship and visit those places in person. They look at pictures and data gathered by spacecraft and satellites to figure out things like how deep the ocean is, what kinds of things are in the water, and whether there might be life swimming around in there.
So, just like regular oceanography helps us learn more about the oceans here on Earth, astrooceanography helps us learn more about the oceans on other planets and moons in outer space. It's a big and exciting field of science that helps us understand our universe a little bit better.