Planetary geology

circular depression in a solid astronomical body formed by the impact of a smaller object

A bolide is normally taken to mean an exceptionally bright meteor, but the term is subject to more than one definition, according to context. It may refer to any large crater-forming body, or to one that explodes in the atmosphere. It can be a synonym for a fireball, sometimes specific to those with an apparent magnitude of −4 or brighter.

unit of mass equal to that of Earth

A chondrite (, ) is a stony (non-metallic) meteorite that has not been modified by either melting or differentiation of the parent body. They are formed when various types of dust and small grains in the early Solar System accreted to form primitive asteroids. Some such bodies that are captured in the planet's gravity well become the most common type of meteorite by arriving on a trajectory toward the planet's surface. Estimates for their contribution to the total meteorite population vary between 85.7% and 86.2%.

alt=An image of two large cryovolcanoes|thumb|upright=1.5|Leviathan Patera (center) and [[Ruach Planitia (upper left), two large cryovolcanic features on Neptune's moon Triton]]

innermost layer(s) of a planet

mean distance from the Earth's center to its surface

geology of astronomical objects

layer inside a planetary body

system of uniquely identifying features on the surface of a planet or natural satellite

chemical elements or compounds with low boiling points associated with planet’s or moon’s crust or atmosphere

large structure of unknown origin on Venus

[[File:Rupes Recta (LROC287 - recta thumb2).png|thumb|Rupes Recta is a well-known linear rille that extends over 100 km in length. Portion of LROC WAC monochrome mosaic, illumination is from the left, and asterisk notes location of LROC NAC (below) [NASA/GSFC/Arizona State University].]] In planetary geology, rupes (, plural: ) are escarpments on planets other than Earth.

area which shows a contrast in albedo with adjacent areas

chain of craters

type of crater whose relief has disappeared

In planetary nomenclature, a chasma (plural: chasmata ) is a deep, elongated, steep-sided depression. As of 2020, the IAU has named 122 such features in the Solar System, on Venus (63), Mars (25), Saturn's satellites Mimas (6), Tethys (2), Dione (8) and Rhea (5), Uranus's satellites Ariel (7), Titania (2) and Oberon (1) and Pluto's satellite Charon (3). An example is Eos Chasma on Mars.

left|thumb|Rima Hyginus, an eminent rille, in selenochromatic format thumb|Rimae on the floor of the lunar crater Gassendi (crater)|Gassendi, from [[Apollo 16.]] thumb|Mamers Valles rille on Mars. thumb|Rima Ariadaeus is categorized as a straight rille (graben) and is over 300 km in length. thumb|Hadley Rille at center is a sinuous rille visited by the Apollo 15 mission. thumb|Detail of part of Hadley Rille

oval feature on Venus or Miranda

distinctive area of broken or jumbled terrain

Scientific study of the surface, crust, and interior of the dwarf planet Pluto

unusually dark area on the surface of a planet or moon

irregular crater

valley in Mars, Moon, etc

thumb|right|Low resolution view of lineae on Europa taken by NASAs Galileo (spacecraft)|Galileo spacecraft.

mons on Venus

impact crater formed by the ejecta that was thrown out of a larger crater

landscape features that have reversed their elevation relative to other features

model representing the average Earth properties as a function of planetary radius

small hill or knob on a celestial body

thumb|right|360 px|False color oblique view of Nilokeras Scopulus on Mars. Mars Orbital Laser Altimeter (MOLA) colorized elevation overlying [[Thermal Emission Imaging System (THEMIS) Infrared (IR) daytime mosaic from Mars Odyssey spacecraft. Yellow and light green represent high elevations; dark green and blue are lower elevations. Image is approximately 175 km across. Vertical exaggeration is 3X.]] In planetary geology, a scopulus (pl. scopuli , from Greek σκόπελος "peak") is a lobate or irregular escarpment. In the early 1970s, the International Astronomical Union (IAU) adopted scopulus as

large area of molten rock on the surface of a planet

where the solid (or liquid) material of the outer crust on certain types of astronomical objects contacts the atmosphere or outer space

flat-topped prominence with cliff-like edges

geologic structure and composition of Ceres

type of impact crater

mountain on a celestial body

volcanic dome on Venus that has experienced collapse and mass wasting such as landslides on its perimeter

award given by the Planetary Geology Division of the Geological Society of America for outstanding contributions to the solution of fundamental problems in planetary geology (1983–)

level representing a mechanical difference between layers in Earth’s inner structure