Terrestrial planets

Mars is the Red Planet: thin CO2 air, giant volcanoes, deep canyons, polar ice, two moons, and strong evidence of ancient water.

Earth is the third planet and only known living world: oceans, oxygen-rich air, magnetic field, plate tectonics, and one large Moon.

Venus is Earth’s size twin and the hottest planet: thick CO2 air, acid clouds, crushing pressure, and a slow backward spin.

Mercury is the closest planet to the Sun: extreme heat and cold, a huge iron core, polar ice, and a day longer than its year.