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A method of measuring a crater is to find the length of the shadow cast by the crater's rim and the angle at which the light source enters. In this measurement, use the geometry of triangles to calculate d (shadow depth) using L (shadow length) and Ø (shadow angle).
The EID lists fewer than ten such craters, and the largest in the last 100,000 years (100 ka) is the 4.5 km (2.8 mi) Rio Cuarto crater in Argentina. [2] However, there is some uncertainty regarding its origins [ 3 ] and age, with some sources giving it as < 10 ka [ 2 ] [ 4 ] while the EID gives a broader < 100 ka.
An impact crater is a depression in the surface of a solid astronomical body formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, [2] impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. [3]
The Burckle crater is an undersea topographic feature about 29 kilometres (18 mi; 16 nmi) in diameter [1] in the southwestern Indian Ocean. A team of Earth scientists called the Holocene Impact Working Group proposes the feature to be an impact crater ; these claims are disputed by other geologists .
If the impact velocity is greater than the speed of sound within the target or impactor material, impact shock causes the material to fracture, and at higher velocities to behave like a gas, causing rapid ejection of target and impactor material and the formation of a crater.
Following are the largest impact craters on various worlds of the Solar System.For a full list of named craters, see List of craters in the Solar System.The ratio column compares the crater diameter with the diameter of the impacted celestial body.
A volcanic crater is a bowl-shaped depression in the ground caused by volcanic activity, usually located above the volcano's vent. [11] During volcanic eruptions, molten magma and volcanic gases rise from an underground magma chamber, through a conduit, until they reach the crater's vent, from where the gases escape into the atmosphere and the magma is erupted as lava.
Shield volcano in Tharsis region on Mars with marked borders, circles represent impact craters counted by crater counting method. Crater counting is a method for estimating the age of a planet's surface based upon the assumptions that when a piece of planetary surface is new, then it has no impact craters; impact craters accumulate after that at a rate that is assumed known.