In Mesopotamian iconography, the crescent was the primary symbol of Nanna-Sîn. LDEX detected an average of one 0.3 micrometer Moon dust particle each minute. The main lunar gravity features are mascons, large positive gravitational anomalies associated with some of the giant impact basins, partly caused by the dense mare basaltic lava flows that fill those basins. [52] Other Apollo lunar samples had in 2012 the same titanium isotopes composition as Earth,[53] which conflicts with what is expected if the Moon formed far from Earth or is derived from Theia. The Moon's apparent size in the sky is almost the same as that of the Sun, since the star is about 400 times the lunar distance and diameter. The crust is on average about 50 kilometres (31 mi) thick. (1987): "Ishango revisited: new age determinations and cultural interpretations", Video (04:56) – The Moon in 4K (NASA, April 2018), Video (04:47) – The Moon in 3D (NASA, July 2018), Exploration of the Moon: Before spaceflight, Apollo 17's Lunar Surface Experiments Package, "The constitution and structure of the lunar interior", "The Population of Near-Earth Asteroids in Coorbital Motion with the Earth", "Topography of the Moon from the Clementine lidar", "Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2009", "Near-Surface Temperatures on Mercury and the Moon and the Stability of Polar Ice Deposits", "The Moon is older than scientists thought", "Naming Astronomical Objects: Spelling of Names", "Gazetteer of Planetary Nomenclature: Planetary Nomenclature FAQ", Late Proto-Indo-European Etymological Lexicon, "Oxford English Dictionary: lunar, a. and n.", "Early formation of the Moon 4.51 billion years ago", "Origin of the moon–The collision hypothesis", Annual Review of Earth and Planetary Sciences, Hawai'i Institute of Geophysics and Planetology, "Asteroids Bear Scars of Moon's Violent Formation", "Earth-Asteroid Collision Formed Moon Later Than Thought", "2008 Pellas-Ryder Award for Mathieu Touboul", "Flying Oceans of Magma Help Demystify the Moon's Creation", "Moonwalk (summary of meeting at Meteoritical Society's 72nd Annual Meeting, Nancy, France)", "Oxygen Isotopes and the Moon-Forming Giant Impact", "Titanium Paternity Test Says Earth is the Moon's Only Parent (University of Chicago)", "The tidal-rotational shape of the Moon and evidence for polar wander", "NASA Research Team Reveals Moon Has Earth-Like Core", "Thermal and magmatic evolution of the Moon", "NASA's LRO Reveals 'Incredible Shrinking Moon, "Lunar Gruithuisen and Mairan domes: Rheology and mode of emplacement", "Global Elemental Maps of the Moon: The Lunar Prospector Gamma-Ray Spectrometer", "A New Moon for the Twenty-First Century", "Ages and stratigraphy of mare basalts in Oceanus Procellarum, Mare Numbium, Mare Cognitum, and Mare Insularum", "Volcanoes Erupted 'Recently' on the Moon", "NASA Mission Finds Widespread Evidence of Young Lunar Volcanism", "Lunar mare deposits associated with the Orientale impact basin: New insights into mineralogy, history, mode of emplacement, and relation to Orientale Basin evolution from Moon Mineralogy Mapper (M3) data from Chandrayaan-1", "Early Earth may have had two moons : Nature News", "Was our two-faced moon in a small collision?
Upcoming lunar missions include Russia's Luna-Glob: an uncrewed lander with a set of seismometers, and an orbiter based on its failed Martian Fobos-Grunt mission.

The Earth revolves around the Earth-Moon barycentre once a sidereal month, with 1/81 the speed of the Moon, or about 12.5 metres (41 ft) per second. The full moon is highest in the sky during winter (for each hemisphere). [172] The periodicity and recurrence of eclipses of the Sun by the Moon, and of the Moon by Earth, is described by the saros, which has a period of approximately 18 years. Mike Wehner has reported on technology and video games for the past decade, covering breaking news and trends in VR, wearables, smartphones, and future tech. [103] In 1994, the bistatic radar experiment located on the Clementine spacecraft, indicated the existence of small, frozen pockets of water close to the surface. [142] With time, the energy of rotation of the Moon on its axis was dissipated as heat, until there was no rotation of the Moon relative to Earth. [135] From images taken by Clementine in 1994, it appears that four mountainous regions on the rim of the crater Peary at the Moon's north pole may remain illuminated for the entire lunar day, creating peaks of eternal light.

[151][152][153] At lower levels, the human perception of reduced brightness as a percentage is provided by the following formula:[154][155], When the actual reduction is 1.00 / 1.30, or about 0.770, the perceived reduction is about 0.877, or 1.00 / 1.14. [78] Moonquakes and releases of gas also indicate some continued lunar activity. The Moon is an exceptionally large natural satellite relative to Earth: Its diameter is more than a quarter and its mass is 1/81 of Earth's.
This age is calculated from isotope dating of lunar zircons.