Mars has a very thin atmosphere which mostly contains carbon dioxide.
It's possible life existed on Mars in the past. Many astronomers and scientists believe Mars was once warmer with a much thicker atmosphere. There could have been a time when Mars was green and flush with water, just like Earth!
The tallest mountain in our solar system is on Mars, it’s called Olympus Mon. It’s a shield volcano that is 13 miles high and has a diameter of about 372 miles.
If you were standing on the surface of Mars, our Sun would appear to be half the size as seen from the surface of Earth.