ИСТИНА

The morphological description of craters was developed at the SAI MSU and was used to compile catalogs of craters on the Moon, Mars and Mercury. Morphological features include: degradation of the rim, terrace or slope collapse, faults, central uplifts (hills, peaks or ridges), crater chains at the bottom, cracks, bottom character, presence of lava at the bottom of the crater, presence of a ray system, underlying terrain: highlands, plains, transition zone. We used MLA altimetry profiles to assess the morphometric parameters of craters. The depths, bottom dimensions, and wall slopes were estimated for craters with a diameter of ≥ 20 km. The distribution of craters by depth depending on the diameter: for diameters from 20 to 100 km and for diameters from 100 km and more. The maximum depth of the craters of Mercury exceeds 6.5 km. It can be seen that large basins in D> 300-400 km have h/D from 0.004 to 0.01. Earlier it was suggested that such a ratio is typical for basins that were formed as a result of collisions with the planet's surface of low-density projectiles, for example, large comets.