Mars and seasonal cycles of Mars are likewise similar to those of Earth, as is the tilt that produces the seasons. 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. The smooth Borealis basin in the northern hemisphere covers 40% of the planet and may be a giant impact feature. Mars has two moons, Phobos and Deimos, which are small and irregularly shaped. These may be captured asteroids, similar to 5261 Eureka, a Mars trojan. There are ongoing investigations
Mount Olympus (Washington) Congress designated 95% of the park as the Olympic Wilderness. Mount Olympus (Washington) Mount Olympus, at 7,980 feet, is the tallest and most prominent mountain in the Olympic Mountains of western Washington state. Located on the Olympic Peninsula, it is also the central feature of Olympic National Park. Mount Olympus is the highest summit of the Olympic Mountains; however, peaks such as Mount Constance, on the eastern margin of the range, are better known, being visible from the Seattle metropolitan area. With notable local relief, Mount Olympus ascends over from the elevation confluence of the Hoh River with Glacier Creek