This happens many years ago. There is a lake on Mars. It is very big. It is 31 miles long and 3 miles wide. It is a freshwater lake. Small organisms live in the water. Other parts of Mars are dry.
There is no lake now. NASA’s robot is on Mars. It explores Mars. The robot finds a special type of material. The material tells scientists about the lake. We know more about the lake now.
Difficult words: freshwater (water with no salt), organism (something alive), dry (there’s no water), explore (look and study).
