WIP

Mars is the fourth planet in order from the Sun and the second smallest planet in the Solar System, after Mercury. 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. Mars is a terrestrial planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the valleys.The average surface temperature on Mars is a frigid -63°C or -81°F compared with Earth's average of 14°C or 57°F. The length of a Martian day is 24 hours and 39 minutes and 35 seconds. The length of a Martian year is significantly longer than Earth's at 687 days. The gravity on Mars' surface is 62% lower than it is on Earth. At just 0.38 of the Earth standard (3.7 vs 9.8 m/s^2), a person who has a mass of 100 kg (220 lbs.) on Earth would have the same 100-kg mass on Mars but the weight on earth of 980 N would only be 373 N on Mars. The diameter of Mars is 53% of Earth's, making it the second smallest planet in the solar system. The surface gravity of Mars is 38% that of Earth, so if you weigh 100 pounds on Earth, you would weigh only 38 pounds on Mars. A year on Mars is 687 days but a day on Mars is only 40 minutes longer than ad day on Earth. Mars has the largest mountain/volcano in the Solar System. Olympus Mons is a shield volcano, three times the height of Everest standing at nearly 22km with a 600 km diameter. Olympus Mons is almost the size of France and some scientists believe that it's still active. A day on mars is referred to as a 'sol'.

Many places on Mars show rocks arranged in layers. Rock can form layers in a variety of ways. Volcanoes, wind, or water can produce layers. Layers may be formed by groundwater rising up depositing minerals and cementing sediments. The hardened layers are consequently more protected from erosion. This process may occur instead of layers forming under lakes.

Schiaparelli is an impact crater on Mars named after Giovanni Schiaparelli located near Mars's equator. It is 461 kilometers (286 miles) in diameter and located at latitude 3° south and longitude 344°. A crater within Schiaparelli shows many layers that may have formed by the wind, volcanoes, or deposition under water. Layers can be a few meters thick or tens of meters thick. Recent research on these layers suggests that ancient climate change on Mars, caused by regular variation in the planet's tilt, may have caused the patterns in layers. On Earth, similar changes (astronomical forcing) of climate results in ice-age cycles. The regular appearance of rock layers suggests that regular changes in climate may be the root cause. Regular changes in climate may be due to variations of a planet's tilt (called obliquity). The tilt of the Earth's axis changes by only a little more than 2 degrees since our moon is relatively large. In contrast Mars's tilt varies by tens of degrees. When the tilt is low (current situation on Mars), the poles are the coldest places on the planet, while the equator is the warmest (as on Earth). This could cause gases in the atmosphere, like water and carbon dioxide, to migrate poleward, where they would freeze. When the obliquity is higher, the poles receive more sunlight, causing those materials to migrate away. When carbon dioxide moves from the Martian poles, the atmospheric pressure increases, possibly causing a difference in the ability of winds to transport and deposit sand. Also, with more water in the atmosphere sand grains may stick and cement together to form layers.

Arabia Terra is a large upland region in the north of Mars in that lies mostly in the Arabia quadrangle, but a small part is in the Mare Acidalium quadrangle. It is densely cratered and heavily eroded. This battered topography indicates great age, and Arabia Terra is presumed to be one of the oldest terrains on the planet. It covers as much as 4,500 km (2,800 mi) at its longest extent, centred roughly at 19.79°N 30°E[1]Coordinates: 19.79°N 30°E with its eastern and southern regions rising 4 km (13,000 ft) above the north-west. Alongside its many craters, canyons wind through the Arabia Terra, many emptying into the large northern lowlands of the planet, which borders Arabia Terra to the north. Arabia contains many interesting features. There are some good examples of pedestal craters in the area. A pedestal crater has its ejecta above the surrounding terrain, often forming a steep cliff. The ejecta forms a resistant layer that protects the underlying material from erosion. Mounds and buttes on the floor of some craters display many layers. The layers may have formed by volcanic processes, by wind, or by underwater deposition. Dark slope streaks have been observed in Tikhonravov Basin, a large eroded crater. The streaks appear on steep slopes and change over time. At first they are dark, then turn a lighter colour, probably by the deposition of fine, light coloured dust from the atmosphere. These streaks are thought to form by dust moving downslope in a way similar to snow avalanches on Earth. Arabia Terra was named in 1879 after a corresponding albedo feature on a map by Giovanni Schiaparelli, who named it in turn after the Arabian peninsula. Research on the region was undertaken in 1997 and the individuality of the province better defined. An equatorial belt was noted with a crater age distinctly younger than the northern part of the province and of Noachis Terra to the south. This was interpreted as an "incipient back-arc system" provoked by the subduction of Mars lowlands under Arabia Terra during Noachian times. Regional fracture patterns were also explained in this manner, and the rotational instability of the planet as a cause was not supported. It contains extension tectonic features. A 2013 study proposed that a number of craters within Arabia Terra, including Eden Patera, Euphrates Patera, Siloe Patera, and possibly Semeykin crater, Ismenia Patera, Oxus Patera and Oxus Cavus, represent calderas formed by massive explosive volcanic eruptions (supervolcanoes) of Late Noachian to Early Hesperian age. Termed "plains-style caldera complexes", these very low relief volcanic features appear to be older than the large Hesperian-age shield volcanoes of Tharsis or Elysium. Eden Patera, for example, is an irregular, 55 by 85 km depression up to 1.8 km deep, surrounded by ridged basaltic plains. It contains three linked interior depressions, demarcated by arcuate scarps, that have terraces suggestive of lava lake drainage and faults suggestive of collapse. The features indicative of impact origin that would be expected in an impact crater of comparable diameter and depth are absent. The authors regard crustal thinning due to regional extension to be a more likely explanation for the origin of the volcanic activity than putative subduction. Rapid ascent of magma through the thin crust and a consequent relative absence of degassing may explain the more explosive eruption style associated with these paterae relative to that of the shield volcanoes. The eruptions would have contributed to the layered deposits of Arabia Terra, which are among the fine-grained deposits widespread in the equatorial regions of Mars. Total eruptive volumes of at least 4,600–7,200 km3 per caldera complex (over its history) were inferred. A meteorite impacted in Arabia Terra some time between 30 June 2002 and 5 October 2003. A single small crater of about 22.6 meters (about 74 feet) in diameter is surrounded by light and dark-toned ejecta - indicating that this impact excavated to a depth where light coloured strata exists. The crater occurs near 20.6 degrees north latitude, 356.8 degrees west longitude, in Arabia Terra. Images of the area show how the impact site appeared to the Mars Odyssey Thermal Emission Imaging System infrared instrument before and after the impact.