claim: Mars is in the Solar System, closer to the sun than Earth.
evidence: Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System , after Mercury .. Sun. Sun. planet. planet. Solar System. Solar System. Mercury. Mercury ( planet ). Named after the Roman god of war , it is often referred to as the `` Red Planet '' because the iron oxide prevalent on its surface gives it a reddish appearance .. Roman god of war. Mars ( mythology ). iron oxide. iron( III ) oxide. reddish appearance. Mars surface color. Mars is a terrestrial planet with a thin atmosphere , having surface features reminiscent both of the impact craters of the Moon and the valleys , deserts , and polar ice caps of Earth .. planet. planet. terrestrial planet. terrestrial planet. atmosphere. atmosphere. Moon. Moon. polar ice caps. polar ice caps. Earth. Earth. The rotational period and seasonal cycles of Mars are likewise similar to those of Earth , as is the tilt that produces the seasons .. Earth. Earth. rotational period. rotational period. Mars is the site of Olympus Mons , the largest volcano and second-highest known mountain in the Solar System , and of Valles Marineris , one of the largest canyons in the Solar System .. Solar System. Solar System. Olympus Mons. Olympus Mons. volcano. volcano. second-highest known mountain in the Solar System. List of tallest mountains in the Solar System. Valles Marineris. Valles Marineris. The smooth Borealis basin in the northern hemisphere covers 40 % of the planet and may be a giant impact feature .. planet. planet. Borealis basin. Borealis basin. Mars has two moons , Phobos and Deimos , which are small and irregularly shaped .. moons. Moons of Mars. Phobos. Phobos ( moon ). Deimos. Deimos ( moon ). These may be captured asteroids , similar to 5261 Eureka , a Mars trojan .. 5261 Eureka. 5261 Eureka. Mars trojan. Mars trojan. There are ongoing investigations assessing the past habitability potential of Mars , as well as the possibility of extant life .. habitability. planetary habitability. the possibility of extant life. Life on Mars. Future astrobiology missions are planned , including the Mars 2020 and ExoMars rovers .. Mars 2020. Mars 2020. ExoMars. ExoMars rover. Liquid water can not exist on the surface of Mars due to low atmospheric pressure , which is about that of the Earth 's , except at the lowest elevations for short periods .. Earth. Earth. water. Water on Mars. The two polar ice caps appear to be made largely of water .. polar ice caps. polar ice caps. water. Water on Mars. The volume of water ice in the south polar ice cap , if melted , would be sufficient to cover the entire planetary surface to a depth of 11 m .. water. Water on Mars. In November 2016 , NASA reported finding a large amount of underground ice in the Utopia Planitia region of Mars .. underground ice. Water on Mars. Utopia Planitia. Utopia Planitia. The volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior .. water. Water on Mars. Lake Superior. Lake Superior. Mars can easily be seen from Earth with the naked eye , as can its reddish coloring .. Earth. Earth. Its apparent magnitude reaches − 2.91 , which is surpassed only by Jupiter , Venus , the Moon , and the Sun .. Sun. Sun. Moons of Mars. Moon. Moon. apparent magnitude. apparent magnitude. Jupiter. Jupiter. Venus. Venus. Optical ground-based telescopes are typically limited to resolving features about 300 km across when Earth and Mars are closest because of Earth 's atmosphere .. atmosphere. atmosphere. Earth. Earth