Tharsis

Okay kiddo, Tharsis is the name of a big rocky planet that is much smaller than Earth. It's named after a big volcanic plateau on the planet's surface that looks like a big scar. When we say rocky planet, that means it's made up of all sorts of rocks and it doesn't have a lot of water or air like Earth does.

Tharsis is special because it has the biggest volcano in our solar system called Olympus Mons. It's so big that if it were put on Earth, it would be almost as tall as Mount Everest or five times higher than the tallest building in the world! But you don't have to worry about it erupting because it hasn't been active for a very long time.

Even though Tharsis doesn't have a lot of water or air, there might have been some long time ago. Scientists think that there might have been rivers and lakes on the planet's surface, but something happened and the water disappeared.

Right now, Tharsis doesn't have any people living on it because it's too far away and it's really hard to survive there without air or water. But scientists are still learning a lot about it from tools like telescopes and robots that go there to explore.