A meteorite is a rock that originated in outer space and has fallen to the surface of a planet or moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a fireball, also known as a shooting star; astronomers call the brightest examples "bolides". Once it settles on the larger body's surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater.
Mare Smythii is a lunar mare located along the equator on the easternmost edge of the Moon's near side, named for the 19th-century British astronomer William Henry Smyth. It is one of only two lunar maria that are named after people, the other being Mare Humboldtianum.
A lunar meteorite is a meteorite that is known to have originated on the Moon. A meteorite hitting the Moon is normally classified as a transient lunar phenomenon.
Amundsen is a large lunar impact crater located near the south pole of the Moon, named after the Norwegian explorer Roald Amundsen. It lies along the southern lunar limb, and so is viewed from the side by an observer on the Earth. To the northwest is the crater Scott, a formation of similar dimensions that is named for another Antarctic explorer. Nobile is attached to the western rim.
Ina is a peculiar small depression on the Moon, in Lacus Felicitatis. It is D-shaped, 2.9 km × 1.9 km wide and 64 m deep.
Paul D. Spudis (1952–2018) was an American geologist and lunar scientist. His specialty was the study of volcanism and impact processes on the planets, including Mercury and Mars.
Space weathering is the type of weathering that occurs to any object exposed to the harsh environment of outer space. Bodies without atmospheres take on many weathering processes:
An ejecta blanket is a generally symmetrical apron of ejecta that surrounds an impact crater; it is layered thickly at the crater's rim and thin to discontinuous at the blanket's outer edge. The impact cratering is one of the basic surface formation mechanisms of the solar system bodies and the formation and emplacement of ejecta blankets are the fundamental characteristics associated with impact cratering event. The ejecta materials are considered as the transported materials beyond the transient cavity formed during impact cratering regardless of the state of the target materials.
The Paul Pellas-Graham Ryder Award is jointly sponsored by the Meteoritical Society and the Planetary Geology Division of the Geological Society of America. It recognizes the best planetary science paper, published during the previous year in a peer-reviewed scientific journal, and written by an undergraduate or graduate student. The topics covered by the award are listed on the cover of Meteoritics and Planetary Science. It has been given since 2002, and honors the memories of the incomparable meteoriticist Paul Pellas and lunar scientist Graham Ryder.
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. Consequently, counting how many craters of various sizes there are in a given area allows determining how long they have accumulated and, consequently, how long ago the surface has formed. The method has been calibrated using the ages obtained by radiometric dating of samples returned from the Moon by the Luna and Apollo missions. It has been used to estimate the age of areas on Mars and other planets that were covered by lava flows, on the Moon of areas covered by giant mares, and how long ago areas on the icy moons of Jupiter and Saturn flooded with new ice.
Secondary craters are impact craters formed by the ejecta that was thrown out of a larger crater. They sometimes form radial crater chains. In addition, secondary craters are often seen as clusters or rays surrounding primary craters. The study of secondary craters exploded around the mid-twentieth century when researchers studying surface craters to predict the age of planetary bodies realized that secondary craters contaminated the crater statistics of a body's crater count.
The Solar System Exploration Research Virtual Institute (SSERVI), originally the NASA Lunar Science Institute, is an organization, established by NASA in 2008, that supplemented and extended existing NASA lunar science programs. Supported by the NASA Science Mission Directorate (SMD) and the Exploration Systems Mission Directorate (ESMD), SSERVI is a NASA program office located at the NASA Ames Research Center and was modeled on the NASA Astrobiology Institute (NAI) with dispersed teams across the nation working together to help lead the agency's research activities related to NASA's human exploration goals. Competitively selected team investigations focused on one or more aspects of lunar science investigations of the Moon, from the Moon, and on the Moon.
Peter H. Schultz is Professor of Geological Sciences at Brown University specializing in the study of planetary geology, impact cratering on the Earth and other objects in the Solar System, and volcanic modifications of planetary surfaces. He was co-investigator to the NASA Science Mission Directorate spacecraft Deep Impact and the Lunar Crater Observation and Sensing Satellite (LCROSS). He was awarded the Barringer Medal of the Meteoritical Society in 2004 for his theoretical and experimental studies of impact craters.
Complex craters are a type of large impact crater morphology. Complex craters are classified into two groups: central-peak craters and peak-ring craters. Peak-ring craters have diameters that are larger in than central-peak craters and have a ring of raised massifs which are roughly half the rim-to-rim diameter, instead of a central peak.
Lunar seismology is the study of ground motions of the Moon and the events, typically impacts or moonquakes, that excite them.
Planetary science is the scientific study of planets, celestial bodies and planetary systems and the processes of their formation. It studies objects ranging in size from micrometeoroids to gas giants, with the aim of determining their composition, dynamics, formation, interrelations and history. It is a strongly interdisciplinary field, which originally grew from astronomy and Earth science, and now incorporates many disciplines, including planetary geology, cosmochemistry, atmospheric science, physics, oceanography, hydrology, theoretical planetary science, glaciology, and exoplanetology. Allied disciplines include space physics, when concerned with the effects of the Sun on the bodies of the Solar System, and astrobiology.
Ursula Bailey Marvin was an American planetary geologist and author who worked for the Smithsonian Astrophysical Observatory.
Inter-crater plains on Mercury are a land-form consisting of plains between craters on Mercury.
Space dust measurement refers to the study of small particles of extraterrestrial material, known as micrometeoroids or interplanetary dust particles (IDPs), that are present in the Solar System. These particles are typically of micrometer to sub-millimeter size and are composed of a variety of materials including silicates, metals, and carbon compounds. The study of space dust is important as it provides insight into the composition and evolution of the Solar System, as well as the potential hazards posed by these particles to spacecraft and other space-borne assets. The measurement of space dust requires the use of advanced scientific techniques such as secondary ion mass spectrometry (SIMS), optical and atomic force microscopy (AFM), and laser-induced breakdown spectroscopy (LIBS) to accurately characterize the physical and chemical properties of these particles.
