If the giant-impact hypothesis is correct, these ratios must be due to some other cause. 1,00-4,00 × 109/l. [6], In 2014, a team in Germany reported that the Apollo samples had a slightly different isotopic signature from Earth rocks. This model, published in 2012 by Robin M. Canup, suggests that the Moon and the Earth formed from a massive collision of two planetary bodies, each larger than Mars, which then re-collided to form what we now call Earth. [8] However, there is no self-consistent model that starts with the giant-impact event and follows the evolution of the debris into a single moon. [24], This empirical data showing close similarity of composition can only be explained by the standard giant-impact hypothesis as an extremely unlikely coincidence, where the two bodies prior to collision somehow had a similar composition. Nonetheless, Darwin's calculations could not resolve the mechanics required to trace the Moon backward to the surface of the Earth. Previously, the age of the Moon had been thought to be 4.527 ± 0.010 billion years. The Moon's oxygen isotopic ratios are essentially identical to those of Earth. Explorateur de tendance. The presence of volatiles such as water trapped in lunar. Geochemistry and Dynamics", Planetary Science Institute: Giant Impact Hypothesis, Klemperer Rosette simulations using Java applets, Origin of the Moon – computer model of accretion, Planet Smash-Up Sends Vaporized Rock, Hot Lava Flying. For example, some orbits may cause the moon to spiral back into the planet. monocyten. [2][13] According to modern theories of planet formation, Theia was part of a population of Mars-sized bodies that existed in the Solar System 4.5 billion years ago. [50], Simulations of the chaotic period of terrestrial planet formation suggest that impacts like those hypothesised to have formed the Moon were common. [19], Not all of the ring material need have been swept up right away: the thickened crust of the Moon's far side suggests the possibility that a second moon about 1,000  km in diameter formed in a Lagrange point of the Moon. [27][28], Another model (2019) to explain the similarity of the Earth and Moon's composition posits that shortly after the Earth formed, it was covered by a sea of hot magma, while the impacting object was likely made of solid material. This way, more material from the primary body would be spun off to form the moon. 0,00-0,10 × 10 9 /l. Several lines of evidence show that if the Moon has an iron-rich core, it must be a small one. [19], Another hypothesis attributes the formation of the Moon to the impact of a large asteroid with the Earth much later than previously thought, creating the satellite primarily from debris from Earth. basofiele granulocyten. zie testbeschrijving in het Diagnostisch Kompas, zie individuele verbindingen in testbeschrijving in het Diagnostisch Kompas, zie tabel testbeschrijving in het Diagnostisch Kompas, zie ook bij testbeschrijving in het Diagnostisch Kompas, zie Diagnostisch Kompas 2003, Totaal Eiwit, zie tabel bij glucosetolerantietest in het Diagnostisch Kompas, afhankelijk van zwangerschapsduur, geboortegewicht en leeftijd, zie tabel in testbeschrijving in het Diagnostisch Kompas, aanbeveling volgens consensus, zie ook tekst in het Diagnostisch Kompas, afkapwaarde (zie test in het Diagnostisch Kompas), zie tabellen bij testbeschrijving in het Diagnostisch Kompas, zie testbeschrijving in het Diagnostisch Kompas, INR (zie ook testbeschrijving in het Diagnostisch Kompas), Xyloseresorptietest, belasting 5 g, urine, Nederlandse Vereniging voor Klinische Chemie en Laboratoriumgeneeskunde. lymfocyten. [4] Supporting evidence includes: However, there remain several questions concerning the best current models of the giant-impact hypothesis. [22], In 2001, a team at the Carnegie Institution of Washington reported that the rocks from the Apollo program carried an isotopic signature that was identical with rocks from Earth, and were different from almost all other bodies in the Solar System. [36], Warm silica-rich dust and abundant SiO gas, products of high velocity (> 10  km/s) impacts between rocky bodies, have been detected by the Spitzer Space Telescope around the nearby (29 pc distant) young (~12 My old) star HD172555 in the Beta Pictoris moving group. For example, the giant-impact hypothesis implies that a surface magma ocean would have formed following the impact. 0,15-0,90 × 10 9 /l. neutrofiele granulocyten. Their models suggested that, at the end of the planet formation period, several satellite-sized bodies had formed that could collide with the planets or be captured. Material in stable Kepler orbits was thus likely to hit the earth-moon system sometime later (because the Earth-Moon system's Kepler orbit around the sun also remains stable). en person uten den faktor eller sykdom som man leter etter, men som i følge testen er positiv. First Name All Authors Title Topic Organization Country Wolfgang Hering W. Hering, A. Onea, A. Jianu, R. Stieglitz, J. Reiser, S. Ulrich Liquid Metals, Materials and Safety Measures to Progress to CSP 2.0 Heat Transfer Fluids Karlsruhe Institute of Technology Germany Xiaoze Du X. For this scenario to be viable, however, the proto-lunar disc would have to endure for about 100 years. konsentrasjonsforskjeller. [55], It has been suggested that other significant objects may have been created by the impact, which could have remained in orbit between the Earth and Moon, stuck in Lagrangian points. 3,884 Followers, 668 Following, 1,055 Posts - See Instagram photos and videos from Tipsbladet (@tipsbladetdk) diffusjon. [59], Other mechanisms that have been suggested at various times for the Moon's origin are that the Moon was spun off from the Earth's molten surface by centrifugal force;[9] that it was formed elsewhere and was subsequently captured by the Earth's gravitational field;[60] or that the Earth and the Moon formed at the same time and place from the same accretion disk. This drifting was later confirmed by American and Soviet experiments, using laser ranging targets placed on the Moon. It is hypothesised that most of the outer silicates of the colliding body would be vaporised, whereas a metallic core would not. The collision speed may have been higher than originally assumed, and this higher velocity may have totally destroyed Theia. [38] A similar belt of warm dust was detected around the star BD+20°307 (HIP 8920, SAO 75016). For other uses, see, American Association for the Advancement of Science, "Origin of the Moon in a giant impact near the end of the Earth's formation", "How Old Is The Moon? How common are Earth-Moon planetary systems? ... De er feilaktig klassifisert som normale. [62][63], Yet another hypothesis proposes that the Moon and the Earth have formed together instead of separately like the giant-impact hypothesis suggests. [9] Using Newtonian mechanics, he calculated that the Moon had orbited much more closely in the past and was drifting away from the Earth. The iron oxide (FeO) content (13%) of the Moon, intermediate between that of Mars (18%) and the terrestrial mantle (8%), rules out most of the source of the proto-lunar material from the Earth's mantle. vag. Du kan se programmer fra både DR1, DR2, DR3, DR K, DR Ultra og DR Ramasjang. Appropriate impact conditions satisfying the angular momentum constraints of the Earth-Moon system yield a Moon formed mostly from the mantles of the Earth and the impactor, while the core of the impactor accretes to the Earth. Le logiciel MediaWiki est utilisé par des dizaines de milliers de sites web et des milliers de sociétés et d’organisations.C’est sur lui que reposent Wikipédia et ce site web. One of the attractive features of the giant-impact hypothesis is that the formation of the Moon and Earth align; during the course of its formation, the Earth is thought to have experienced dozens of collisions with planet-sized bodies. to determine whether or not this is possible. Many prior models had suggested 80% of the Moon coming from the impactor.[29][30]. [23] The difference was slight, but statistically significant. According to research (2012) to explain similar compositions of Earth and the Moon based on simulations at the University of Bern by physicist Andreas Reufer and his colleagues, Theia collided directly with Earth instead of barely swiping it. Likewise, the proximity of the planet to the star will also affect the orbital evolution. [citation needed]. < 30 mg/24 uur As the two moons migrated outward from the Earth, solar tidal effects would have made the Lagrange orbit unstable, resulting in a slow-velocity collision that "pancaked" the smaller moon onto what is now the far side of the Moon, adding material to its crust. [64][65] After the re-collision, Earth was surrounded by a disk of material, which accreted to form the Moon. telling av de ulike typene hvite blodlegemer i et blodutstryk. [32] Zinc is strongly fractionated when volatilised in planetary rocks,[33][34] but not during normal igneous processes,[35] so zinc abundance and isotopic composition can distinguish the two geological processes. [58] The resulting mass irregularities would subsequently produce a gravity gradient that resulted in tidal locking of the Moon so that today, only the near side remains visible from Earth. ", "Traces of another world found on the Moon", "Retuschen an der Entstehungsgeschichte des Erdtrabanten", "Huge impact could have smashed early Earth into a doughnut shape", "Ocean of magma blasted into space may explain how the moon formed", "Isotopic fractionation of zinc in tektites", "Dating the Moon-forming impact event with asteroidal meteorites", "KAGUYA observation of global emissions of indigenous carbon ions from the Moon", "Oxygen Isotopes Give Clues to the Formation of Planets, Moons, and Asteroids", "Titanium paternity test fingers Earth as moon's sole parent", Philosophical Transactions of the Royal Society A, "Earth Had Two Moons That Crashed to Form One, Study Suggests", "Earth-Asteroid Collision Formed Moon Later Than Thought", "Forming a Moon with an Earth-like Composition via a Giant Impact", "NASA Lunar Scientists Develop New Theory on Earth and Moon Formation", "Origin of the Moon. The more volatile materials that were emitted during the collision probably would escape the Solar System, whereas silicates would tend to coalesce.[12]. Other remaining questions include when the Moon lost its share of volatile elements and why Venus – which experienced giant impacts during its formation – does not host a similar moon. New Concept. [51], In 2004, Princeton University mathematician Edward Belbruno and astrophysicist J. Richard Gott III proposed that Theia coalesced at the L4 or L5 Lagrangian point relative to Earth (in about the same orbit and about 60° ahead or behind),[52][53] similar to a trojan asteroid. Kom gerust langs en praat mee! [52] In this scenario, gravitational perturbations by planetesimals caused Theia to depart from its stable Lagrangian location, and subsequent interactions with proto-Earth led to a collision between the two bodies. The Earth would have gained significant amounts of angular momentum and mass from such a collision. This designation was proposed initially by the English geochemist Alex N. Halliday in 2000 and has become accepted in the scientific community. [3][17] Theia's iron core would have sunk into the young Earth's core, and most of Theia's mantle accreted onto the Earth's mantle. However, a significant portion of the mantle material from both Theia and the Earth would have been ejected into orbit around the Earth (if ejected with velocities between orbital velocity and escape velocity) or into individual orbits around the Sun (if ejected at higher velocities). In 2007, researchers from the California Institute of Technology showed that the likelihood of Theia having an identical isotopic signature as the Earth was very small (less than 1 percent). eosinofiele granulocyten. In 1898, George Darwin made the suggestion that the Earth and Moon were once a single body. Lunar magma cannot pierce through the thick crust of the far side, causing fewer lunar maria, while the near side has a thin crust displaying the large maria visible from Earth. This is an unstable state that could have been generated by yet another collision to get the rotation spinning fast enough. Se eller gense DR's TV-programmer. The name of the hypothesised protoplanet is derived from the mythical Greek titan Theia /ˈθiːə/, who gave birth to the Moon goddess Selene. We would like to show you a description here but the site won’t allow us. The stable-isotope ratios of lunar and terrestrial rock are identical, implying a common origin. If such a moon-forming event had occurred there, a possible explanation of why the planet does not have such a moon might be that a second collision occurred that countered the angular momentum from the first impact. Yet there is no evidence that the Earth ever had such a magma ocean and it is likely there exists material that has never been processed in a magma ocean.[40]. The Late Heavy Bombardment by much smaller asteroids occurred later – approximately 3.9 billion years ago. According to this modification, the composition of Theia is not so restricted, making a composition of up to 50% water ice possible. A number of compositional inconsistencies need to be addressed. Laboratoriumonderzoek speelt bij 70% van de diagnoses een sleutelrol,  Let op: deze waarden geven alleen een indicatie! Regardless of the speed and tilt of the Earth's rotation before the impact, it would have experienced a day some five hours long after the impact, and the Earth's equator and the Moon's orbit would have become coplanar. Mit unserem Immobilienmarktplatz immo.inFranken.de, das Immobilienportal von inFranken.de, dem reichweitenstärkstem Nachrichten- und Informationsportal in der fränkischen Region, steht Ihnen für Ihre Suche nach einer Immobilie in Franken ein starker Partner zur Seite. The smaller moon may have remained in orbit for tens of millions of years. [37] A belt of warm dust in a zone between 0.25AU and 2AU from the young star HD 23514 in the Pleiades cluster appears similar to the predicted results of Theia's collision with the embryonic Earth, and has been interpreted as the result of planet-sized objects colliding with each other. One possible explanation is that Theia formed near the Earth. After several tens of years, the disk spread beyond the Roche limit, and started producing new objects that continued the growth of the Moon, until the inner disk was depleted in mass after several hundreds of years. [61] The impact in this scenario would have created a magma ocean on Earth and the proto-Moon with both bodies sharing a common plasma metal vapor atmosphere. However, mapping by the GRAIL mission has ruled out this scenario. They proposed that one of these objects may have collided with the Earth, ejecting refractory, volatile-poor dust that could coalesce to form the Moon. The inner disk slowly and viscously spread back out to the Earth's Roche limit, pushing along outer bodies via resonant interactions. Groupe PSA, afgekort PSA, is een Franse autoconcern die de automerken Peugeot, Citroën, Opel, Vauxhall en DS Automobiles omvat. In 2019 produceerde PSA zo'n 3,5 miljoen voertuigen en behaalde het een omzet van 75 miljard euro. Modelling suggests that this would lead to the impact heating the magma much more than solids from the impacting object, leading to more material being ejected from the proto-Earth, so that about 80% of the Moon-forming debris originated from the proto-Earth. This hypothesis could explain evidence that others do not. Elk met hun eigen stijl, voorkeur en soms zelfs met wat exclusieve, interactieve content. We would like to show you a description here but the site won’t allow us. [57] This collision, simulations have supported, would have been at a low enough velocity so as not to form a crater; instead, the material from the smaller body would have spread out across the Moon (in what would become its far side), adding a thick layer of highlands crust. Earth's spin and the Moon's orbit have similar orientations. Work is ongoing[when?] The shared metal vapor bridge would have allowed material from the Earth and proto-Moon to exchange and equilibrate into a more common composition. The Moon-forming collision would have been only one such "giant impact" but certainly the last significant impactor event. [32], Collisions between ejecta escaping Earth's gravity and asteroids would have left impact heating signatures in stony meteorites; analysis based on assuming the existence of this effect has been used to date the impact event to 4.47 billion years ago, in agreement with the date obtained by other means. This collision could potentially explain the unique geological and geochemical properties of the Moon. [26], One effort (2018) to homogenise the products of the collision was to energise the primary body by way of a greater pre-collision rotational speed. If the Moon was formed by such an impact, it is possible that other inner planets also may have been subjected to comparable impacts. The giant-impact hypothesis is currently the favored scientific hypothesis for the formation of the Moon. [10] Little attention was paid to Professor Daly's challenge until a conference on satellites in 1974, during which the idea was reintroduced and later published and discussed in Icarus in 1975 by Drs. The net effect is that it is more likely for impact-generated moons to survive when they orbit more distant terrestrial planets and are aligned with the planetary orbit. [54] A 2014 comparison of computer simulations with elemental abundance measurements in the Earth's mantle indicated that the collision occurred approximately 95 My after the formation of the Solar System. William K. Hartmann and Donald R. Davis. Google permet désormais aux hôtels et aux plateformes de réservation d’être référencés gratuitement sur sa section dédiée aux voyages.