Isaev is a
lunar impact crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...
on the
far side of the
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width ...
. It is entirely contained within the much larger walled plain
Gagarin, and lies in the northwestern part of Gagarin's interior floor. The northwestern outer rim of Isaev is attached to the inner rim of Gagarin.
Although younger than Gagarin, in which it lies, this is still an eroded crater formation. The southern rim is broken through by the smaller satellite crater Isaev N. Tiny craterlets lie along the rim and inner walls of Isaev. A short chain of craterlets forms a gouge along the western inner wall. Within the interior floor is a large, triple-lobed area of lower
albedo
Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refl ...
material. Such darker surfaces on the Moon are typically formed by flows of
basalt
Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90% of a ...
ic
lava
Lava is molten or partially molten rock ( magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or ...
.
Satellite craters
By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Isaev.
References
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External links
LTO-102B2 Lunar Topographic Orthophotomap, Isaev
Impact craters on the Moon