Fretted terrain

Fretted terrain is a fancy word used by scientists to describe an area on a planet where there are lots of hills and valleys, or bumps and grooves. Imagine you're playing with playdough and you make a big flat pancake. If you take a fork and press it into the pancake, you'll make little lines on the surface. Fretted terrain is like those little lines, but on a much bigger scale, and on a planet instead of a piece of playdough.

Scientists have found fretted terrain on different planets and moons in our solar system, like Mars and Europa. They think that these strange landscapes were created by different things, like the shifting of tectonic plates (big puzzle pieces that make up the surface of planets), or ice melting and flowing, or even rocks and soil being blown around by wind.

Basically, fretted terrain is just a fancy way to talk about places where the ground looks interesting and bumpy, and scientists are still trying to figure out how it all happened.