| 词条 | Virrat (crater) |
| 释义 |
| titlecolor = #FA8072 | title = Virrat | image = Dinorwic crater area.png | caption = The crater Virrat and its surroundings, in a screenshot in NASA World Wind | coordinate_title = Coordinates | globe = Mars | coordinates = {{coord|31.1|S|103|W|globe:mars_type:landmark|display=inline,title}} | diameter = 54 km | depth = 1.3 km | eponym = Virrat, Finland }}Virrat is an impact crater on Mars, approximately 54 kilometres in diameter. It is located at 31.1°S, 103°W, southwest of the crater Dinorwic and northeast of Clantas Fossae. Several Virrat crater radii to the north are the craters Koga and Nhill. It is named after Virrat, a town in Finland.[1][2] According to a surface age map of Mars based on US Geological Survey data, the area around Virrat is from the Noachian epoch, which places the area's age at 3.8 to 3.5 billion years ago.[3] At the highest point on its rim, it is about 6,400 metres above zero altitude, and it is about 5,100 metres at the crater bottom, giving it a depth of 1.3 kilometres.[2] References1. ^{{gpn|6405|Virrat}} {{Geography of Mars}}{{portal bar|Mars}}{{Mars-stub}}2. ^1 NASA World Wind 1.4. NASA Ames Research Center, 2007. 3. ^{{cite web | title=INTEGRATING GLOBAL-SCALE MISSION DATASETS – UNDERSTANDING THE MARTIAN CRUST | work=lpi.usra.edu | url=http://www.lpi.usra.edu/meetings/lpsc2005/pdf/1853.pdf | accessdate=October 22, 2007 }} 1 : Impact craters on Mars |
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