Origin of the Moon

Last updated
The Moon's heavily cratered far-side Cara-oculta-luna.jpg
The Moon's heavily cratered far-side

The origin of the Moon is usually explained by a Mars-sized body striking the Earth, creating a debris ring that eventually collected into a single natural satellite, the Moon, but there are a number of variations on this giant-impact hypothesis, as well as alternative explanations, and research continues into how the Moon came to be formed. [1] [2] Other proposed scenarios include captured body, fission, formed together (condensation theory, synestia), planetesimal collisions (formed from asteroid-like bodies), and collision theories. [3]

Contents

The standard giant-impact hypothesis suggests that a Mars-sized body, called Theia, impacted the proto-Earth, creating a large debris ring around Earth, which then accreted to form the Moon. This collision also resulted in the 23.5° tilted axis of the Earth, thus causing the seasons. [1] [ irrelevant citation ] The Moon's oxygen isotopic ratios seem to be essentially identical to Earth's. [4] Oxygen isotopic ratios, which may be measured very precisely, yield a unique and distinct signature for each Solar System body. [5] If Theia had been a separate protoplanet, it probably would have had a different oxygen isotopic signature than proto-Earth, as would the ejected mixed material. [6] Also, the Moon's titanium isotope ratio (50Ti/47Ti) appears so close to the Earth's (within 4 parts per million) that little if any of the colliding body's mass could likely have been part of the Moon. [7]

Formation

"One of the challenges to the longstanding theory of the collision, is that a Mars-sized impacting body, whose composition likely would have differed substantially from that of Earth, likely would have left Earth and the moon with different chemical compositions, which they are not."

—NASA [1]

Lunar sample 61016, better known as "Big Muley" Lunar Sample 61016 - Big Muley.jpg
Lunar sample 61016, better known as "Big Muley"

Some theories have been stated that presume the proto-Earth had no large moons early in the formation of the Solar System, 4.425 billion years ago, Earth being basically rock and lava. Theia, an early protoplanet the size of Mars, hit Earth in such a way that it ejected a considerable amount of material away from Earth. Some proportion of these ejecta escaped into space, but the rest consolidated into a single spherical body in orbit about Earth, creating the Moon.

The hypothesis requires a collision between a proto-Earth about 90% of the diameter of present Earth, and another body the diameter of Mars (half of the terrestrial diameter and a tenth of its mass). The latter has sometimes been referred to as Theia, the name of the mother of Selene, the Moon goddess in Greek mythology. This size ratio is needed in order for the resulting system to have sufficient angular momentum to match the current orbital configuration. Such an impact would have put enough material into orbit around Earth to have eventually accumulated to form the Moon.

Computer simulations show a need for a glancing blow, which causes a portion of the collider to form a long arm of material that then shears off. The asymmetrical shape of the Earth following the collision then causes this material to settle into an orbit around the main mass. The energy involved in this collision is impressive: possibly trillions of tonnes of material would have been vaporized and melted. In parts of the Earth, the temperature would have risen to 10,000 °C (18,000 °F).

The Moon's relatively small iron core (compared to other rocky planets and moons in the Solar System) is explained by Theia's core mostly merging into that of Earth. The lack of volatiles in the lunar samples is also explained in part by the energy of the collision. The energy liberated during the reaccretion of material in orbit around Earth would have been sufficient to melt a large portion of the Moon, leading to the generation of a magma ocean.

The newly formed Moon orbited at about one-tenth the distance that it does today, and spiraled outward because of tidal friction transferring angular momentum from the rotations of both bodies to the Moon's orbital motion. Along the way, the Moon's rotation became tidally locked to Earth, so that one side of the Moon continually faces toward Earth. Also, the Moon would have collided with and incorporated any small preexisting satellites of Earth, which would have shared the Earth's composition, including isotopic abundances. The geology of the Moon has since been more independent of the Earth.

A 2012 study on the depletion of zinc isotopes on the Moon found evidence for volatile depletion consistent with the giant-impact origin for Earth and the Moon. [8] In 2013, a study was released that indicated that water in lunar magma is indistinguishable from that in carbonaceous chondrites and nearly the same as that of Earth in isotopic composition. [9] [10] [11]

Derivatives of the hypothesis

Although the giant-impact hypothesis explains many aspects of the Earth–Moon system, there are still a few unresolved problems, such as the Moon's volatile elements not being as depleted as expected from such an energetic impact. [12]

Another issue is lunar and Earth isotope comparisons. In 2001, the most precise measurement yet of the isotopic signatures of Moon rocks was published. [4] Surprisingly, the Apollo lunar samples carried an isotopic signature identical to Earth rocks, but different from other Solar System bodies. Because most of the material that went into orbit to form the Moon was thought to come from Theia, this observation was unexpected. In 2007, researchers from Caltech showed that the likelihood of Theia having an identical isotopic signature as the Earth is very small (less than 1 percent chance). [13] Published in 2012, an analysis of titanium isotopes in Apollo lunar samples showed that the Moon has the same composition as Earth, [14] which conflicts with the Moon forming far from Earth's orbit.

Merger of two planets

To help resolve these problems, a theory published in 2012 posits that two bodies—each five times the size of Mars—collided, then recollided, forming a large disc of mixed debris that eventually formed Earth and the Moon. [1]

Immediate origin of the Moon as a post-impact satellite

Simulation of the formation of the moon caused by a giant impact.

The Moon is traditionally thought to have coalesced from the debris ejected by a giant impact onto the early Earth. However, such models struggle to explain the similar isotopic compositions of Earth and lunar rocks at the same time as the system's angular momentum, and the details of potential impact scenarios are hotly debated. Above a high resolution threshold for simulations, a study published in 2022 finds that giant impacts can immediately place a satellite with similar mass and iron content to the Moon into orbit far outside Earth's Roche limit. Even satellites that initially pass within the Roche limit can reliably and predictably survive, by being partially stripped and then torqued onto wider, stable orbits. Furthermore, the outer layers of these directly formed satellites are molten over cooler interiors and are composed of around 60% proto-Earth material. This could alleviate the tension between the Moon's Earth-like isotopic composition and the different signature expected for the impactor. Immediate formation opens up new options for the Moon's early orbit and evolution, including the possibility of a highly tilted orbit to explain the lunar inclination, and offers a simpler, single-stage scenario for the origin of the Moon. [15]

Multiple impacts

In 2004, Russian astrophysicist Nikolai Gorkavyi proposed a novel model titled the multiple large asteroid impacts model, [16] [17] which found support from a notable group of Russian astronomers in 2013 [18] and later, in 2017, by planetary researchers at Weizmann Institute of Science in Rehovot, Israel. [19] In general terms, the main idea of the model suggests that the Moon was formed as a result of a violent rain of large asteroids (1–100 km) that repeatedly hammered the fledgling Earth over millions of years. Such a series of smaller impacts, which were likely more common in the early Solar System, could blast enough rocky Earth debris into orbit to form a protosatellite disk which later forms into a small moonlet. [17] [19] As repeated impacts created more balls of debris, the moonlets could merge over time into one large moon. [17] [19]

Synestia hypothesis

In 2018 researchers at Harvard and the UC Davis developed computer models demonstrating that one possible outcome of a planetary collision is that it creates a synestia, a mass of vaporized rock and metal which forms a biconcave disc extending beyond the lunar orbit. The synestia will eventually shrink and cool to accrete the satellite and reform the impacted planet. [20]

Moon – Oceanus Procellarum ("Ocean of Storms")
14-236-LunarGrailMission-OceanusProcellarum-Rifts-Overall-20141001.jpg
Ancient rift valleys – rectangular structure (visible – topography – GRAIL gravity gradients) (October 1, 2014).
PIA18822-LunarGrailMission-OceanusProcellarum-Rifts-Overall-20141001.jpg
Ancient rift valleys – context.
PIA18821-LunarGrailMission-OceanusProcellarum-Rifts-Closeup-20141001.jpg
Ancient rift valleys – closeup (artist's concept).

Other hypotheses

Density [21]
BodyDensity
g/cm3
Mercury5.4
Venus5.2
Earth5.5
Moon3.3

Capture

This hypothesis states that the Moon was captured by the Earth. [22] This model was popular until the 1980s, and some points in its favor are the Moon's size, orbit, and tidal locking. [22]

One problem is understanding the capture mechanism. [22] A close encounter of two planetary bodies typically results in either collision or altered trajectories. For this hypothesis to work, there might have been a large atmosphere around the primitive Earth, which would slow the movement of the Moon by aerobraking before it could escape. That hypothesis may also explain the irregular satellite orbits of Jupiter and Saturn. [23] However, this hypothesis does not adequately explain the essentially identical oxygen isotope ratios of the two bodies. [4]

Earth and Moon to scale, 500 km per pixel Earth-moon-to-scale.svg
Earth and Moon to scale, 500 km per pixel

Fission

This is the now discredited hypothesis that an ancient, rapidly spinning Earth expelled a piece of its mass. [22] [24] This was first proposed by George Darwin (son of the famous biologist Charles Darwin) in 1879 [25] and retained some popularity until Apollo. [22] The Austrian geologist Otto Ampferer in 1925 also suggested the emerging of the Moon as cause for continental drift. [26]

It was proposed that the Pacific Ocean represented the scar of this event. [22] Today it is known that the oceanic crust that makes up this ocean basin is relatively young, about 200 million years old or less, whereas the Moon is much older. The Moon does not consist of oceanic crust but of mantle material, which originated inside the proto-Earth in the Precambrian. [7]

Thorium concentrations on the Moon, as mapped by Lunar Prospector Lunar Thorium concentrations.jpg
Thorium concentrations on the Moon, as mapped by Lunar Prospector

Accretion

The hypothesis of accretion suggests that the Earth and the Moon formed together as a double system from the primordial accretion disk of the Solar System [27] or even a black hole. [28] The problem with this hypothesis is that it does not explain the angular momentum of the Earth-Moon system or why the Moon has a relatively small iron core compared to the Earth (25% of its radius compared to 50% for the Earth). [27]

Nuclear explosion

Dutch scientists Rob de Meijer and Wim van Westrenen suggested in 2010 that the Moon may have formed from a nuclear explosion caused by the centrifugal force of an earlier, spinning proto-Earth. The centrifugal force would have concentrated heavy elements such as thorium and uranium on the equatorial plane and at the boundary between the Earth's outer core and mantle. If the concentrations of these radioactive elements were high enough, this could have led to a nuclear chain reaction that became supercritical, causing a nuclear explosion ejecting the Moon into orbit. [29] [30] [31] This natural nuclear fission reactor has been observed on Earth at a much smaller scale.

Additional theories and studies

Evolution of the Moon video by NASA circa 2012. [32]

2011

In 2011, it was theorized that a second moon existed 4.5 billion years ago, and later had an impact with the Moon, as a part of the accretion process in the formation of the Moon. [33]

2013

One hypothesis, presented only as a possibility, was that the Earth captured the Moon from Venus. [34]

2017

Uranium–lead dating of Apollo 14 zircon fragments shows the age of the Moon to be about 4.51 billion years. [35] [36]

2020

A team of researchers of the Miniature Radio Frequency (Mini-RF) instrument on NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft concluded that the Moon's subsurface may be richer in metals, like iron and titanium, more than scientists had believed. [37]

In July 2020 scientists report that the Moon formed 4.425 ±0.025 bya, about 85 million years later than thought, and that it hosted an ocean of magma for substantially longer than previously thought (for ~200 million years). [38] [39] [40]

2023

On 1 November 2023, scientists reported that, according to computer simulations, remnants of a protoplanet, named Theia, could be inside the Earth, left over from a collision with the Earth in ancient times, and afterwards becoming the Moon. [41] [42]

See also

Related Research Articles

<span class="mw-page-title-main">Moon</span> Natural satellite orbiting Earth

The Moon is Earth's only natural satellite. It orbits at an average distance of 384,400 km (238,900 mi), about 30 times the diameter of Earth. Over time Earth's gravity has caused tidal locking, causing the same side of the Moon to always face Earth. Because of this, the lunar day and the lunar month are the same length, at 29.5 Earth days. The Moon's gravitational pull – and to a lesser extent, the Sun's – are the main drivers of Earth's tides.

<span class="mw-page-title-main">Giant-impact hypothesis</span> Theory of the formation of the Moon

The giant-impact hypothesis, sometimes called the Big Splash, or the Theia Impact, is an astrogeology hypothesis for the formation of the Moon first proposed in 1946 by Canadian geologist Reginald Daly. The hypothesis suggests that the Early Earth collided with a Mars-sized dwarf planet of the same orbit approximately 4.5 billion years ago in the early Hadean eon, and the ejecta of the impact event later accreted to form the Moon. The impactor planet is sometimes called Theia, named after the mythical Greek Titan who was the mother of Selene, the goddess of the Moon.

<span class="mw-page-title-main">Oceanus Procellarum</span> Vast lunar mare on the western edge of the near side of Earths Moon

Oceanus Procellarum is a vast lunar mare on the western edge of the near side of the Moon. It is the only one of the lunar maria to be called an "Oceanus" (ocean), due to its size: Oceanus Procellarum is the largest of the maria ("seas"), stretching more than 2,500 km (1,600 mi) across its north–south axis and covering roughly 4,000,000 km2 (1,500,000 sq mi), accounting for 10.5% of the total lunar surface area.

<span class="mw-page-title-main">Crust (geology)</span> Outermost solid shell of astronomical bodies

In geology, the crust is the outermost solid shell of a planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be distinguished based on its phase.

<span class="mw-page-title-main">KREEP</span> Geochemical component of some lunar rocks, potassium, lanthanides, and phosphorus

KREEP, an acronym built from the letters K, REE and P, is a geochemical component of some lunar impact breccia and basaltic rocks. Its most significant feature is somewhat enhanced concentration of a majority of so-called "incompatible" elements and the heat-producing elements, namely radioactive uranium, thorium, and potassium.

<span class="mw-page-title-main">Planetary differentiation</span> Astrogeological concept

In planetary science, planetary differentiation is the process by which the chemical elements of a planetary body accumulate in different areas of that body, due to their physical or chemical behavior. The process of planetary differentiation is mediated by partial melting with heat from radioactive isotope decay and planetary accretion. Planetary differentiation has occurred on planets, dwarf planets, the asteroid 4 Vesta, and natural satellites.

<span class="mw-page-title-main">Planetary core</span> Innermost layer(s) of a planet

A planetary core consists of the innermost layers of a planet. Cores may be entirely solid or entirely liquid, or a mixture of solid and liquid layers as is the case in the Earth. In the Solar System, core sizes range from about 20% to 85% of a planet's radius (Mercury).

<span class="mw-page-title-main">Geology of the Moon</span> Structure and composition of the Moon

The geology of the Moon is quite different from that of Earth. The Moon lacks a true atmosphere, and the absence of free oxygen and water eliminates erosion due to weather. Instead, the surface is eroded much more slowly through the bombardment of the lunar surface by micrometeorites. It does not have any known form of plate tectonics, it has a lower gravity, and because of its small size, it cooled faster. In addition to impacts, the geomorphology of the lunar surface has been shaped by volcanism, which is now thought to have ended less than 50 million years ago. The Moon is a differentiated body, with a crust, mantle, and core.

<span class="mw-page-title-main">Formation and evolution of the Solar System</span> Modelling its structure and composition

There is evidence that the formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a protoplanetary disk out of which the planets, moons, asteroids, and other small Solar System bodies formed.

<span class="mw-page-title-main">Lunar magma ocean</span> Theorized historical geological layer on the Moon

The Lunar Magma Ocean (LMO) is the layer of molten rock that is theorized to have been present on the surface of the Moon. The Lunar Magma Ocean was likely present on the Moon from the time of the Moon's formation to tens or hundreds of millions of years after that time. It is a thermodynamic consequence of the Moon's relatively rapid formation in the aftermath of a giant impact between the proto-Earth and another planetary body. As the Moon accreted from the debris from the giant impact, gravitational potential energy was converted to thermal energy. Due to the rapid accretion of the Moon, thermal energy was trapped since it did not have sufficient time to thermally radiate away energy through the lunar surface. The subsequent thermochemical evolution of the Lunar Magma Ocean explains the Moon's largely anorthositic crust, europium anomaly, and KREEP material.

<span class="mw-page-title-main">Internal structure of the Moon</span>

Having a mean density of 3,346.4 kg/m3, the Moon is a differentiated body, being composed of a geochemically distinct crust, mantle, and planetary core. This structure is believed to have resulted from the fractional crystallization of a magma ocean shortly after its formation about 4.5 billion years ago. The energy required to melt the outer portion of the Moon is commonly attributed to a giant impact event that is postulated to have formed the Earth-Moon system, and the subsequent reaccretion of material in Earth orbit. Crystallization of this magma ocean would have given rise to a mafic mantle and a plagioclase-rich crust.

Robin M. Canup is an American astrophysicist. Her main area of research concerns the origins of planets and satellites. In 2003, Canup was awarded the Harold C. Urey Prize. In April, 2022, Canup presented the findings of the Planetary Science Decadal Survey as co-chair of the Survey Steering Committee with Philip R. Christensen.

<span class="mw-page-title-main">Earth trojan</span> Asteroid with which Earth shares its orbit around the Sun

An Earth trojan is an asteroid that orbits the Sun in the vicinity of the Earth–Sun Lagrangian points L4 (leading 60°) or L5 (trailing 60°), thus having an orbit similar to Earth's. Only two Earth trojans have so far been discovered. The name "trojan" was first used in 1906 for the Jupiter trojans, the asteroids that were observed near the Lagrangian points of Jupiter's orbit.

<span class="mw-page-title-main">History of Solar System formation and evolution hypotheses</span>

The history of scientific thought about the formation and evolution of the Solar System began with the Copernican Revolution. The first recorded use of the term "Solar System" dates from 1704. Since the seventeenth century, philosophers and scientists have been forming hypotheses concerning the origins of our Solar System and the Moon and attempting to predict how the Solar System would change in the future. René Descartes was the first to hypothesize on the beginning of the Solar System; however, more scientists joined the discussion in the eighteenth century, forming the groundwork for later hypotheses on the topic. Later, particularly in the twentieth century, a variety of hypotheses began to build up, including the now-commonly accepted nebular hypothesis.

<span class="mw-page-title-main">Late Heavy Bombardment</span> Hypothesized astronomical event

The Late Heavy Bombardment (LHB), or lunar cataclysm, is a hypothesized astronomical event thought to have occurred approximately 4.1 to 3.8 billion years (Ga) ago, at a time corresponding to the Neohadean and Eoarchean eras on Earth. According to the hypothesis, during this interval, a disproportionately large number of asteroids and comets collided into the terrestrial planets and their natural satellites of the inner Solar System, including Mercury, Venus, Earth and Mars. These came from both post-accretion and planetary instability-driven populations of impactors. Although it used to be widely accepted, it remained difficult to provide an overwhelming amount of evidence for the hypothesis. However, recent re-appraisal of the cosmo-chemical constraints indicates that there was likely no late spike in the bombardment rate.

<span class="mw-page-title-main">Theia (planet)</span> Planet hypothesized to have impacted Earth and created the Moon

Theia is a hypothesized ancient planet in the early Solar System which, according to the giant-impact hypothesis, collided with the early Earth around 4.5 billion years ago, with some of the resulting ejected debris coalescing to form the Moon. Such a collision, with the two planets' cores and mantles fusing, could explain why Earth's core is larger than expected for a body its size. Collision simulations support the idea that the large low-shear-velocity provinces in the lower mantle may be remnants of Theia. Theia is hypothesized to have been about the size of Mars, and may have formed in the outer Solar System and provided much of Earth's water, though this is debated.

<span class="mw-page-title-main">Satellite system (astronomy)</span> Set of gravitationally bound objects in orbit

A satellite system is a set of gravitationally bound objects in orbit around a planetary mass object or minor planet, or its barycenter. Generally speaking, it is a set of natural satellites (moons), although such systems may also consist of bodies such as circumplanetary disks, ring systems, moonlets, minor-planet moons and artificial satellites any of which may themselves have satellite systems of their own. Some bodies also possess quasi-satellites that have orbits gravitationally influenced by their primary, but are generally not considered to be part of a satellite system. Satellite systems can have complex interactions including magnetic, tidal, atmospheric and orbital interactions such as orbital resonances and libration. Individually major satellite objects are designated in Roman numerals. Satellite systems are referred to either by the possessive adjectives of their primary, or less commonly by the name of their primary. Where only one satellite is known, or it is a binary with a common centre of gravity, it may be referred to using the hyphenated names of the primary and major satellite.

<span class="mw-page-title-main">Magma ocean</span>

Magma oceans are vast fields of surface magma that exist during periods of a planet's or some natural satellite's accretion when the celestial body is completely or partly molten.

The K/U Ratio is the ratio of a slightly volatile element, potassium (K), to a highly refractory element, uranium (U). It is a useful way to measure the presence of volatile elements on planetary surfaces. The K/U ratio helps explain the evolution of the planetary system and the origin of Earth's moon.

The Secret History of the Moon is a 2020 short speculative animated documentary film created by astronomy-themed musician and filmmaker John D. Boswell. It explores the proposed explanations on how the Moon was formed, using rocks collected by Neil Armstrong and Buzz Aldrin during the 1969 Apollo 11 mission. The film was released on Boswell's YouTube channel Melodysheep on April 30.

References

  1. 1 2 3 4 "NASA Lunar Scientists Develop New Theory on Earth and Moon Formation". NASA . Archived from the original on 2023-05-18.
  2. ↑ Staff (September 7, 2014). "Revisiting the Moon". New York Times . Retrieved September 8, 2014.
  3. ↑ Theories of Formation for the Moon
  4. 1 2 3 Wiechert, U.; Halliday, A. N.; Lee, D.-C.; Snyder, G. A.; Taylor, L. A.; Rumble, D. (October 2001). "Oxygen Isotopes and the Moon-Forming Giant Impact". Science. 294 (12): 345–348. Bibcode:2001Sci...294..345W. doi:10.1126/science.1063037. PMID   11598294. S2CID   29835446.
  5. ↑ Scott, Edward R. D. (December 3, 2001). "Oxygen Isotopes Give Clues to the Formation of Planets, Moons, and Asteroids". Planetary Science Research Discoveries Report: 55. Bibcode:2001psrd.reptE..55S . Retrieved 2010-03-19.
  6. ↑ Nield, Ted (September 2009). "Moonwalk" (PDF). Geological Society of London. p. 8. Retrieved 2010-03-01.
  7. 1 2 Zhang, Junjun; Nicolas Dauphas; Andrew M. Davis; Ingo Leya; Alexei Fedkin (25 March 2012). "The proto-Earth as a significant source of lunar material". Nature Geoscience. 5 (4): 251–255. Bibcode:2012NatGe...5..251Z. doi:10.1038/ngeo1429.
  8. ↑ Paniello, Randal C.; Day, James M. D.; Moynier, Frédéric (18 October 2012). "Zinc isotopic evidence for the origin of the Moon". Nature . 490 (7420). London, England: Springer Nature: 376–9. Bibcode:2012Natur.490..376P. doi:10.1038/nature11507. PMID   23075987. S2CID   4422136.
  9. ↑ Spudis, Paul D. (May 14, 2013). "Earth-Moon: A Watery "Double-Planet"". Air & Space/Smithsonian. Archived from the original on 2013-08-07.
  10. ↑ Saal, A. E.; et al. (14 June 2013). "Hydrogen Isotopes in Lunar Volcanic Glasses and Melt Inclusions Reveal a Carbonaceous Chondrite Heritage". Science . 340 (6138). Washington, D.C.: American Association for the Advancement of Science: 1317–20. Bibcode:2013Sci...340.1317S. doi:10.1126/science.1235142. PMID   23661641. S2CID   9092975.
  11. ↑ Erik Ian Asphaug: Impact Origin of the Moon? . In: Annual Revue of Earth and Planetary Sciences. March 2014.
  12. ↑ Jones, J. H. "TESTS OF THE GIANT IMPACT HYPOTHESIS" (PDF). Origin of the Earth and Moon Conference. Retrieved 2006-11-21.
  13. ↑ Pahlevan, Kaveh; Stevenson, David (October 2007). "Equilibration in the Aftermath of the Lunar-forming Giant Impact". Earth and Planetary Science Letters. 262 (3–4): 438–449. arXiv: 1012.5323 . Bibcode:2007E&PSL.262..438P. doi:10.1016/j.epsl.2007.07.055. S2CID   53064179.
  14. ↑ University of Chicago (2012-04-05). "Titanium Paternity Test Says Earth is the Moon's Only Parent". Astrobiology Magazine (Press release). Archived from the original on 2012-06-27.{{cite web}}: CS1 maint: unfit URL (link)
  15. ↑ Kegerreis, J.A.; et al. (4 October 2022). "Immediate Origin of the Moon as a Post-impact Satellite". The Astrophysical Journal Letters. 937 (L40): L40. arXiv: 2210.01814 . Bibcode:2022ApJ...937L..40K. doi: 10.3847/2041-8213/ac8d96 .
  16. ↑ Gorkavyi, N. N. (2004-05-01). "The New Model of the Origin of the Moon". AAS/Division of Dynamical Astronomy Meeting #35. 35: 07.11. Bibcode:2004DDA....35.0711G.
  17. 1 2 3 "Greenwich Institute for Science and Technology - The Origin of the Moon and Satellites". www.gist.us. Retrieved 2021-03-01.
  18. ↑ "Development of the theory of the origin and early evolution of the earth". ResearchGate. Retrieved 2021-03-01.
  19. 1 2 3 Rufu, Raluca; Aharonson, Oded; Perets, Hagai B. (February 2017). "A multiple-impact origin for the Moon". Nature Geoscience. 10 (2): 89–94. arXiv: 1903.02525 . Bibcode:2017NatGe..10...89R. doi:10.1038/ngeo2866. ISSN   1752-0908. S2CID   16658852.
  20. ↑ Barbuzano, Javier (March 1, 2018). "Could a Giant Impact Have Vaporized Earth to Create the Moon?". Sky and Telescope. Retrieved March 3, 2018.
  21. ↑ The Formation of the Moon
  22. 1 2 3 4 5 6 "Lunar Origin. JNot a valid reference must be a Scientifi publication". Archived from the original on 2018-03-23. Retrieved 2018-03-23.
  23. ↑ Jewitt, David; Haghighipour, Nader (2007). "Irregular Satellites of the Planets: Products of Capture in the Early Solar System". Annual Review of Astronomy and Astrophysics. 45 (1): 261–295. arXiv: astro-ph/0703059 . Bibcode:2007ARA&A..45..261J. doi:10.1146/annurev.astro.44.051905.092459. S2CID   13282788.
  24. ↑ Robin M. Canup, Kevin Righter, Nicolas Dauphas et al.: Origin of the Moon . In: Reviews in Mineralogy and Geochemistry. Vol. 89, No 1. Dec. 2023.
  25. ↑ Wise, D. U. (1966). "Origin of the Moon by Fission". In Marsden, B. G.; Cameron, A. G. W. (eds.). The Earth-Moon System. Boston, MA: Springer. pp. 213–223. doi:10.1007/978-1-4684-8401-4_14. ISBN   978-1-4684-8403-8.
  26. ↑ Ampferer, O. (July 1925). "Über Kontinentverschiebungen". Naturwissenschaften (in German). 13 (31): 669–675. Bibcode:1925NW.....13..669A. doi:10.1007/BF01558835. S2CID   40767867. Fulltext page 672.
  27. 1 2 The Formation of the Moon burro.cwru.edu
  28. ↑ "Where did the Moon come from? BBC". Archived from the original on 2019-10-26. Retrieved 2019-10-08.
  29. ↑ "The Moon may have formed in a nuclear explosion".
  30. ↑ De Meijer, R.J.; Anisichkin, V.F.; Van Westrenen, W. (2013). "Forming the Moon from terrestrial silicate-rich material". Chemical Geology. 345: 40–49. arXiv: 1001.4243 . Bibcode:2013ChGeo.345...40D. doi:10.1016/j.chemgeo.2012.12.015. S2CID   55166272.
  31. ↑ M. Reuver, R. J. de Meijer, Inge Loes ten Kate, Wim van Westrenen: Boundary conditions for the formation of the Moon . In: Netherland Journal of Geosciences, vol. 95, issue 2, 14. December 2015.
  32. ↑ "NASA | Evolution of the Moon". YouTube .
  33. ↑ Jutzi, M. (2011). "Forming the lunar farside highlands by accretion of a companion moon". Nature. 476 (7358): 69–72. Bibcode:2011Natur.476...69J. doi:10.1038/nature10289. PMID   21814278. S2CID   84558.
  34. ↑ Did We Steal Our Moon From Venus? Is our planet a dirty thief?, Popular Science, 09.27.2013 at 5:07 pm
  35. ↑ Melanie Barboni; Patrick Boehnke; Brenhin Keller; Issaku E. Kohl; Blair Schoene; Edward D. Young; Kevin D. McKeegan (January 11, 2017). "Early formation of the Moon 4.51 billion years ago". Science Advances . 3 (1): e1602365. Bibcode:2017SciA....3E2365B. doi:10.1126/sciadv.1602365. PMC   5226643 . PMID   28097222.
  36. ↑ Wolpert, Stuart (January 11, 2017). "The moon is older than scientists thought, UCLA-led research team reports". University of California, Los Angeles.
  37. ↑ Heggy, Essam; Palmer, E.M.; Thompson, T.W.; Thomson, B.J.; Patterson, G.W. (2020). "Bulk composition of regolith fines on lunar crater floors: Initial investigation by LRO/Mini-RF". Earth and Planetary Science Letters. 541 (116274): 116274. Bibcode:2020E&PSL.54116274H. doi:10.1016/j.epsl.2020.116274. S2CID   219509384.
  38. ↑ "Researchers find younger age for Earth's moon". phys.org. 13 July 2020. Retrieved 16 August 2020.
  39. ↑ Lennon, Annie (13 July 2020). "Earth's Moon Had Magma Ocean for 200 Million Years | Space". LabRoots. Retrieved 16 August 2020.
  40. ↑ Maurice, M.; Tosi, N.; Schwinger, S.; Breuer, D.; Kleine, T. (10 July 2020). "A long-lived magma ocean on a young Moon". Science Advances. 6 (28): eaba8949. Bibcode:2020SciA....6.8949M. doi: 10.1126/sciadv.aba8949 . ISSN   2375-2548. PMC   7351470 . PMID   32695879. CC-BY icon.svg Text and images are available under a Creative Commons Attribution 4.0 International License.
  41. ↑ Chang, Kenneth (1 November 2023). "A 'Big Whack' Formed the Moon and Left Traces Deep in Earth, a Study Suggests - Two enormous blobs deep inside Earth could be remnants of the birth of the moon". The New York Times . Archived from the original on 1 November 2023. Retrieved 2 November 2023.
  42. ↑ Yuan, Qian; et al. (1 November 2023). "Moon-forming impactor as a source of Earth's basal mantle anomalies". Nature . 623: 95–99. doi:10.1038/s41586-023-06589-1. Archived from the original on 2 November 2023. Retrieved 2 November 2023.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.