Are Earth and Mars a similar size?
Earth is bigger. Earth is about twice the diameter of Mars and more than 6 times the volume.
The size of Mars is similar to Earth's size, and its gravitational pull is about the same force of that of Earth. Mars has a layer of frozen liquid beneath its dusty orange surface. This liquid is believed to be the same liquid as Earth's water. Mars is also believed to possibly support living microbes like those on planet Earth.