Because it's a) a planet and b) orange to red in color.
Some things about Mars could be categorized as rocket science, but this is not one of them.
Planet Mars is known as the red planet.
Mars is the planet known as the red planet
Mars is known as a red planet.
Mars is known as the red planet. This is because the iron in the soil gives it a red color. Mars is thought to have once had lakes and oceans.
It is Mars that is known as the red planet.
Mars is also known as the "Red Planet" due to its reddish appearance caused by iron oxide (rust) on its surface.
The planet Mars is known as the red planet. It is the fourth planet from the Sun an the second smallest planet in our Solar System.
Mars is known for the deep red color it has. It's even called the Red Planet sometimes!
its red thts y
Mars
Mars is known as the red planet, so my guess is Red ☼
Mars.