Planeten. • Zwergplaneten. • Natürliche Satelliten. (Monde). • Kleinkörper Verlust des neunten Planeten ☹ american-cabin-rentals.com Und zwar die vier inneren Gesteinsplaneten, die recht klein sind: Merkur, Venus, Erde und Mars. Dann – immer von der Sonne nach außen gesehen – die vier. IMP-Schülerinnen erstellen Planeten-Wiki. Da die Lernplattform „Moodle“ am St.-Dominikus-Gymnasium schon seit zehn Jahren eingesetzt wird, konnte sie sehr.
SonnensystemDer jüdische Geschäftsmann Max Emden aus Hamburg machte in den er Jahren mit Kaufhäusern wie dem KaDeWe in Berlin oder dem Oberpollinger in. Unser Sonnensystem hat 8 Planeten. Die und einem Planeten besteht darin, dass der Stern ein heißer american-cabin-rentals.com%28Planet% Ein Planet ist ein großer Himmelskörper, der sich um eine Sonne bewegt. Das Klexikon ist wie eine Wikipedia für Kinder und Schüler.
Wiki Planeten Navigationsmenü VideoStar Size Comparison 2 The Planets Orchestral suite by Gustav Holst First UK edition Opus32 Based onPlanets in astrology Composed –16 Movementsseven ScoringOrchestra Premiere Date29 September LocationQueen's Hall, London ConductorAdrian Boult The Planets, Op. 32, is a seven-movement orchestral suite by the English composer Gustav Holst, written between and Each movement of the suite is named after a planet of the solar system and its corresponding astrological character as defined by Holst. 1 "Here to kill!" - PLANET//SHAPER Information: Appearance: How to Obtain: Fun Fact: This stand was named after the Pose Music,  which was an Album and song made by Camellia. Planet Shaper has deep purple accessories on such as a belt, a hat with cat ears, and wristbands. The stand itself is a solid, smooth, lighter red color. The stand has large, neon yellow claws and a neon. The first civilization known to have a functional theory of the planets were the Babylonians, who lived in Mesopotamia in the first and second millennia BC. The oldest surviving planetary astronomical text is the Babylonian Venus tablet of Ammisaduqa, a 7th-century BC copy of a list of observations of the motions of the planet Venus, that probably dates as early as the second millennium BC. Planet Nine, sometimes incorrectly referred to as Planet X, is a hypothetical planet in the outer region of the Solar System. Its gravitational effects could explain the unusual clustering of orbits for a group of extreme trans-Neptunian objects (eTNOs), bodies beyond Neptune that orbit the Sun at distances averaging more than times that of the Earth. Planeten hebben genoeg massa om een ronde vorm te benaderen, maar te weinig massa om in hun binnenste tot kernfusie te leiden, zodat ze zelf geen licht geven. In het zonnestelsel bewegen acht planeten om de Zon. De Aarde is daarvan zeer waarschijnlijk de enige waarop leven voorkomt. The solar wind interacts with these regions, elongating the magnetosphere on Jupiter's lee side and extending it outward until it nearly reaches the orbit of Saturn. Carpo Themisto Valetudo. Retrieved March 30, The ground shows evidence of extensive volcanismand the sulfur in the Wiki Planeten may indicate that there have been recent eruptions. Anfang waren über extrasolare Planeten bekannt. Retrieved 22 February Als wel aan de eerste twee voorwaarden wordt voldaan, maar niet aan de derde, wordt het betreffende hemellichaam een dwergplaneet genoemd. Brown ovals are warmer and located within the "normal cloud layer". Visite Leggi Modifica Modifica wikitesto Cronologia. The last three features were named before the current system was adopted by the International Volkswagen Anleihe Unionthe body which oversees planetary Mustersuche Kostenlos Spielen. Main article: Geophysical definition of 'planet'. Galileo Messenger 6. Portale Musica classica : accedi alle voci di Wikipedia che trattano di musica classica. He particularly disliked having to finish with Jupiter, to make a 'happy ending', for, WildgewГјrze he himself said, 'in the real Sakura Lady Slot the end is not happy at Ziehung Deutsche Sportlotterie.
Wiki Planeten andere wenden. - InhaltsverzeichnisWie war Heinrich Böll als Kind?
Wanneer de massa van de maan groot genoeg is om het massamiddelpunt buiten het oppervlakte van de planeet te plaatsen, spreekt men van een dubbelplaneet.
Bij de dwergplaneet Pluto en diens maan Charon ligt dit punt buiten Pluto, zodat er sprake is van een dubbeldwergplaneet.
Omdat Charon kleiner is dan Pluto, wordt Charon desondanks vaak als maan beschouwd. Enkele relatief dicht bij de Aarde staande planeten zijn in de oudheid al beschreven doordat zij met het blote oog zichtbaar zijn.
Mercurius was rond v. De eerste gedetailleerde beschrijvingen van Venus dateren uit de 17e eeuw v. Ook Jupiter en Saturnus waren in de oudheid bekend, doordat deze planeten vaak als zeer heldere sterren aan de hemel stonden.
Andere planeten zijn vanaf de Aarde niet met het blote oog zichtbaar. In ontdekte Galileo Galilei met een telescoop de vier grootste manen van Jupiter, de eerste manen rond een andere planeet.
Uranus en Neptunus werden voor het eerst waargenomen met behulp van telescopen. In werd Pluto voor het eerst waargenomen tijdens het vergelijken van fotografische platen.
Vanaf halverwege de jaren negentig van de 20e eeuw zijn de eerste planeten buiten het zonnestelsel ontdekt. The suite has seven movements, each named after a planet and its corresponding astrological character see Planets in astrology :.
Holst's original title, as seen on the handwritten full score, was "Seven Pieces for Large Orchestra". A typical performance of all seven movements is about fifty minutes long, though Holst's own electric recording from is just over forty-two and a half minutes.
One explanation for the suite's structure, presented by Holst scholar Raymond Head, is the ruling of astrological signs of the zodiac by the planets:  if the signs are listed along with their ruling planets in the traditional order starting with Aries , ignoring duplication and the luminaries the Sun and Moon , the order of the movements corresponds.
Critic David Hurwitz offers an alternative explanation for the piece's structure: that Jupiter is the centrepoint of the suite and that the movements on either side are in mirror images.
Thus Mars involves motion and Neptune is static; Venus is sublime while Uranus is vulgar, and Mercury is light and scherzando while Saturn is heavy and plodding.
This hypothesis is lent credence by the fact that the two outer movements, Mars and Neptune, are both written in rather unusual quintuple meter.
Holst suffered neuritis in his right arm, which caused him to seek help from Vally Lasker and Nora Day, two amanuenses , in scoring The Planets.
Neptune was one of the first pieces of orchestral music to have a fade-out ending,  although several composers including Joseph Haydn in the finale of his Farewell Symphony had achieved a similar effect by different means.
Holst stipulates that the women's choruses are "to be placed in an adjoining room, the door of which is to be left open until the last bar of the piece, when it is to be slowly and silently closed", and that the final bar scored for choruses alone is "to be repeated until the sound is lost in the distance".
Several attempts have been made, for a variety of reasons, to append further music to Holst's suite, though by far the most common presentation of the music in the concert hall and on record remains Holst's original seven-movement version.
Pluto was discovered in , four years before Holst's death, and was hailed by astronomers as the ninth planet. Holst, however, expressed no interest in writing a movement for the new planet.
He had become disillusioned by the popularity of the suite, believing that it took too much attention away from his other works.
In the final broadcast of his Young People's Concerts series in March , the conductor Leonard Bernstein led the New York Philharmonic through a fairly straight interpretation of the suite, though he discarded the Saturn movement because he thought the theme of old age was irrelevant to a concert for children.
The broadcast concluded with an improvised performance he called "Pluto, the Unpredictable". Matthews also changed the ending of Neptune slightly so that movement would lead directly into Pluto.
The suite was arranged for concert band and premiered in The work contains original themes, themes from The Planets, and other popular Holst melodies.
Holst adapted the melody of the central section of Jupiter in to fit the metre of a poem beginning " I Vow to Thee, My Country ".
Da Wikipedia, l'enciclopedia libera. URL consultato il 9 settembre Herold, September einen Nur noch die Planeten, die seit der Antike bekannt waren, plus Uranus und Neptun galten weiterhin als Planeten.
Damit sank die Zahl der vollwertigen Planeten auf acht. März entdeckte Clyde W. Viele Astronomen rechneten ihn schon früh dem Kuipergürtel zu, einem Reservoir von Kometen und Asteroiden , das im Inneren bis an die Neptunbahn heranreicht.
Damit wurde Pluto in die gleichzeitig geschaffene Klasse der Zwergplaneten eingestuft, deren Form durch ihre Gravitation und die durch ihre Rotation verursachten Zentrifugalkräfte bestimmt ist, ohne dass sie Planeten sind.
Alle weiteren kleineren Körper wurden zu den so genannten Kleinkörpern zusammengefasst. Bis dahin hatte es kein klar definiertes Unterscheidungsmerkmal zwischen Planeten und Asteroiden gegeben.
Auf der Generalversammlung der IAU in Prag wurden am August offizielle Definitionen für verschiedene Klassen der die Sonne umlaufenden Himmelskörper verabschiedet — und damit hauptsächlich die erste wissenschaftliche Definition eines Planeten.
Bereinigt im Sinne der Definition hat ein Planet auch Körper, die er in Bahnresonanzen gezwungen hat. Dies trifft u. Für Planeten und Zwergplaneten jenseits der Neptunbahn war ursprünglich die Bezeichnung Plutonen vorgeschlagen worden, deren Prototyp Pluto gewesen wäre.
Weil aber bereits in der Geologie der gleichlautende Fachbegriff Pluton verwendet wird, kam es hinsichtlich dieser Namensgebung zu keiner Einigung.
Gegen die in Prag beschlossene Planetendefinition regt sich Kritik von Astronomen. Eine Expertenkommission hatte im Vorfeld der Konferenz eine Definition erarbeitet, die eine Erhöhung der Planetenanzahl auf 12 vorsah.
Hauptkritikpunkte an der verabschiedeten Definition sind:. Eine Gruppe von Astronomen hat deswegen eine Petition verfasst, in der sie die Aufhebung dieser Definition und eine neue Abstimmung fordern.
August fand dieser Antrag Unterschriften. The magnetic fields of Uranus and Neptune are strongly tilted relative the rotational axis and displaced from the centre of the planet.
In , a team of astronomers in Hawaii observed an extrasolar planet around the star HD , which appeared to be creating a sunspot on the surface of its parent star.
Several planets or dwarf planets in the Solar System such as Neptune and Pluto have orbital periods that are in resonance with each other or with smaller bodies this is also common in satellite systems.
All except Mercury and Venus have natural satellites , often called "moons". Earth has one, Mars has two, and the giant planets have numerous moons in complex planetary-type systems.
Many moons of the giant planets have features similar to those on the terrestrial planets and dwarf planets, and some have been studied as possible abodes of life especially Europa.
The four giant planets are also orbited by planetary rings of varying size and complexity. The rings are composed primarily of dust or particulate matter, but can host tiny ' moonlets ' whose gravity shapes and maintains their structure.
Although the origins of planetary rings is not precisely known, they are believed to be the result of natural satellites that fell below their parent planet's Roche limit and were torn apart by tidal forces.
No secondary characteristics have been observed around extrasolar planets. The sub-brown dwarf Cha , which has been described as a rogue planet , is believed to be orbited by a tiny protoplanetary disc  and the sub-brown dwarf OTS 44 was shown to be surrounded by a substantial protoplanetary disk of at least 10 Earth masses.
From Wikipedia, the free encyclopedia. This article is about the astronomical object. For planets in astrology, see Planets in astrology.
For other uses, see Planet disambiguation. Class of astronomical body directly orbiting a star or stellar remnant. Further information: History of astronomy , Definition of planet , and Timeline of Solar System astronomy.
Main article: Babylonian astronomy. See also: Greek astronomy. Main articles: Indian astronomy and Hindu cosmology.
Main articles: Astronomy in the medieval Islamic world and Cosmology in medieval Islam. See also: Heliocentrism.
Main article: IAU definition of planet. See also: List of former planets. See also: Weekday names and Naked-eye planet.
Main article: Nebular hypothesis. Supernova remnant ejecta producing planet-forming material. Solar System — sizes but not distances are to scale.
The Sun and the eight planets of the Solar System. The inner planets , Mercury , Venus , Earth , and Mars.
Main article: Solar System. See also: List of gravitationally rounded objects of the Solar System. Main article: Exoplanet.
Main article: Geophysical definition of 'planet'. Main article: Dwarf planet. Main article: Rogue planet.
See also: Five-planet Nice model. Main article: Sub-brown dwarf. Main article: Satellite planet. Main articles: Orbit and Orbital elements.
Main article: Axial tilt. Main article: Clearing the neighbourhood. Main article: Planetary mass. Main article: Planetary differentiation.
Main articles: Atmosphere and Extraterrestrial atmospheres. See also: Extraterrestrial skies. Main article: Magnetosphere.
Main articles: Natural satellite and Planetary ring. Astronomy portal Solar System portal Space portal. The official definition applies only to the Solar System, whereas the definition applies to planets around other stars.
The extrasolar planet issue was deemed too complex to resolve at the IAU conference. This statistic is an extrapolation from data on K-type stars.
The term "satellite" had already begun to be used to distinguish such bodies from those around which they orbited "primary planets".
International Astronomical Union. Retrieved Archived from the original on Retrieved 10 May The Extrasolar Planets Encyclopaedia.
New York Times. Kubas; J. Beaulieu; M. Dominik; et al. Bibcode : Natur. Archived from the original on 7 November Retrieved 7 November Proceedings of the National Academy of Sciences.
Bibcode : PNAS.. The Library of Congress. Merriam-Webster OnLine. Retrieved 29 June Oxford English Dictionary. Journal of Near Eastern Studies.
Astronomy in China, Korea and Japan Walker ed. The Copernican Revolution. Harvard University Press.
The outermost layer of the atmosphere contains crystals of frozen ammonia. Through infrared and ultraviolet measurements, trace amounts of benzene and other hydrocarbons have also been found.
The atmospheric proportions of hydrogen and helium are close to the theoretical composition of the primordial solar nebula.
Neon in the upper atmosphere only consists of 20 parts per million by mass, which is about a tenth as abundant as in the Sun. This depletion is a result of precipitation of these elements into the interior of the planet.
Based on spectroscopy , Saturn is thought to be similar in composition to Jupiter, but the other giant planets Uranus and Neptune have relatively less hydrogen and helium and relatively more ices and are thus now termed ice giants.
Jupiter's mass is 2. So, for example, the extrasolar planet HD b has a mass of 0. Theoretical models indicate that if Jupiter had much more mass than it does at present, it would shrink.
As a result, Jupiter is thought to have about as large a diameter as a planet of its composition and evolutionary history can achieve.
Although Jupiter would need to be about 75 times as massive to fuse hydrogen and become a star , the smallest red dwarf is only about 30 percent larger in radius than Jupiter.
However, the Juno mission , which arrived in July ,  found that Jupiter has a very diffuse core, mixed into the mantle. Above the layer of metallic hydrogen lies a transparent interior atmosphere of hydrogen.
At this depth, the pressure and temperature are above hydrogen's critical pressure of 1. Physically, there is no clear boundary—the gas smoothly becomes hotter and denser as one descends.
The temperature and pressure inside Jupiter increase steadily inward, due to the Kelvin—Helmholtz mechanism.
Prior models of Jupiter's interior suggested a core radius of 0. Early results from the Juno mission suggest the core may be larger and more diffuse with a radius from 0.
Jupiter is perpetually covered with clouds composed of ammonia crystals and possibly ammonium hydrosulfide.
The clouds are located in the tropopause and are arranged into bands of different latitudes, known as tropical regions.
These are sub-divided into lighter-hued zones and darker belts. The interactions of these conflicting circulation patterns cause storms and turbulence.
There may also be a thin layer of water clouds underlying the ammonia layer. Supporting the idea of water clouds are the flashes of lightning detected in the atmosphere of Jupiter.
These electrical discharges can be up to a thousand times as powerful as lightning on Earth. The orange and brown coloration in the clouds of Jupiter are caused by upwelling compounds that change color when they are exposed to ultraviolet light from the Sun.
The exact makeup remains uncertain, but the substances are thought to be phosphorus, sulfur or possibly hydrocarbons. The zones are formed when rising convection cells form crystallizing ammonia that masks out these lower clouds from view.
Jupiter's low axial tilt means that the poles constantly receive less solar radiation than at the planet's equatorial region.
Convection within the interior of the planet transports more energy to the poles, balancing out the temperatures at the cloud layer. It is known to have been in existence since at least ,  and possibly since The Great Red Spot is large enough to accommodate Earth within its boundaries.
Storms such as this are common within the turbulent atmospheres of giant planets. Jupiter also has white ovals and brown ovals, which are lesser unnamed storms.
White ovals tend to consist of relatively cool clouds within the upper atmosphere. Brown ovals are warmer and located within the "normal cloud layer".
Such storms can last as little as a few hours or stretch on for centuries. Even before Voyager proved that the feature was a storm, there was strong evidence that the spot could not be associated with any deeper feature on the planet's surface, as the Spot rotates differentially with respect to the rest of the atmosphere, sometimes faster and sometimes more slowly.
In , an atmospheric feature formed in the southern hemisphere that is similar in appearance to the Great Red Spot, but smaller. This was created when several smaller, white oval-shaped storms merged to form a single feature—these three smaller white ovals were first observed in It has since increased in intensity and changed color from white to red.
They found that, while the Spot changes size, shape and intensity over the short term, it has maintained its general position in the atmosphere across more than 15 years of available data.
Scientists believe the Spot is a giant vortex similar to the Great Red Spot and also appears to be quasi-stable like the vortices in Earth's thermosphere.
Interactions between charged particles generated from Io and the planet's strong magnetic field likely resulted in redistribution of heat flow, forming the Spot.
Jupiter's magnetic field is fourteen times as strong as that of Earth, ranging from 4. The volcanoes on the moon Io emit large amounts of sulfur dioxide , forming a gas torus along the moon's orbit.
The gas is ionized in the magnetosphere, producing sulfur and oxygen ions. They, together with hydrogen ions originating from the atmosphere of Jupiter, form a plasma sheet in Jupiter's equatorial plane.
The plasma in the sheet co-rotates with the planet, causing deformation of the dipole magnetic field into that of a magnetodisk.
Electrons within the plasma sheet generate a strong radio signature that produces bursts in the range of 0. At about 75 Jupiter radii from the planet, the interaction of the magnetosphere with the solar wind generates a bow shock.
Surrounding Jupiter's magnetosphere is a magnetopause , located at the inner edge of a magnetosheath —a region between it and the bow shock. The solar wind interacts with these regions, elongating the magnetosphere on Jupiter's lee side and extending it outward until it nearly reaches the orbit of Saturn.
The four largest moons of Jupiter all orbit within the magnetosphere, which protects them from the solar wind.
The magnetosphere of Jupiter is responsible for intense episodes of radio emission from the planet's polar regions.
Volcanic activity on Jupiter's moon Io see below injects gas into Jupiter's magnetosphere, producing a torus of particles about the planet.
As a result, radio waves are generated through a cyclotron maser mechanism , and the energy is transmitted out along a cone-shaped surface.
When Earth intersects this cone, the radio emissions from Jupiter can exceed the solar radio output. This is approximately two-fifths the orbital period of Saturn, forming a near orbital resonance between the two largest planets in the Solar System.
Because the eccentricity of its orbit is 0. The axial tilt of Jupiter is relatively small: only 3. As a result, it does not experience significant seasonal changes, in contrast to, for example, Earth and Mars.
Jupiter's rotation is the fastest of all the Solar System's planets, completing a rotation on its axis in slightly less than ten hours; this creates an equatorial bulge easily seen through an Earth-based amateur telescope.
The planet is shaped as an oblate spheroid , meaning that the diameter across its equator is longer than the diameter measured between its poles.
Because Jupiter is not a solid body, its upper atmosphere undergoes differential rotation. System II applies at all latitudes north and south of these; its period is 9h 55m System III was first defined by radio astronomers , and corresponds to the rotation of the planet's magnetosphere; its period is Jupiter's official rotation.
Jupiter is usually the fourth brightest object in the sky after the Sun, the Moon and Venus ;  at times Mars is brighter than Jupiter.
Earth overtakes Jupiter every As it does so, Jupiter appears to undergo retrograde motion with respect to the background stars.
That is, for a period Jupiter seems to move backward in the night sky, performing a looping motion. Because the orbit of Jupiter is outside that of Earth, the phase angle of Jupiter as viewed from Earth never exceeds It was only during spacecraft missions to Jupiter that crescent views of the planet were obtained.
The planet Jupiter has been known since ancient times. It is visible to the naked eye in the night sky and can occasionally be seen in the daytime when the Sun is low.
They used Jupiter's roughly year orbit along the ecliptic to define the constellations of their zodiac. The astronomical symbol for the planet, , is a stylized representation of the god's lightning bolt.
The original Greek deity Zeus supplies the root zeno- , used to form some Jupiter-related words, such as zenographic.
Jovian is the adjectival form of Jupiter. The older adjectival form jovial , employed by astrologers in the Middle Ages , has come to mean "happy" or "merry", moods ascribed to Jupiter's astrological influence.
In Vedic astrology , Hindu astrologers named the planet after Brihaspati , the religious teacher of the gods, and often called it " Guru ", which literally means the "Heavy One".
In Central Asian Turkic myths , Jupiter is called Erendiz or Erentüz , from eren of uncertain meaning and yultuz "star".
There are many theories about the meaning of eren. These peoples calculated the period of the orbit of Jupiter as 11 years and days.
They believed that some social and natural events connected to Erentüz's movements on the sky. The observation of Jupiter dates back to at least the Babylonian astronomers of the 7th or 8th century BC.
By the 4th century BC, these observations had developed into the Chinese zodiac ,  with each year associated with a Tai Sui star and god controlling the region of the heavens opposite Jupiter's position in the night sky; these beliefs survive in some Taoist religious practices and in the East Asian zodiac's twelve animals, now often popularly assumed to be related to the arrival of the animals before Buddha.
If accurate, this would predate Galileo's discovery by nearly two millennia. In , Italian polymath Galileo Galilei discovered the four largest moons of Jupiter now known as the Galilean moons using a telescope; thought to be the first telescopic observation of moons other than Earth's.
One day after Galileo, Simon Marius independently discovered moons around Jupiter, though he did not publish his discovery in a book untilFor other uses, see Planet (disambiguation). The Planets, Op. 32, is a seven- movement orchestral suite by the English composer Gustav Holst, written between and Each movement of the suite is named after a planet of the solar system and its corresponding astrological character as defined by american-cabin-rentals.com on: Planets in astrology. Een planeet is een hemellichaam dat om een ster beweegt. Planeten hebben genoeg massa om een ronde vorm te benaderen, maar te weinig massa om in hun binnenste tot kernfusie te leiden, zodat ze zelf geen licht geven. In het zonnestelsel bewegen acht planeten om de Zon. De Aarde is daarvan zeer waarschijnlijk de enige waarop leven voorkomt. In het sterrenstelsel waartoe de Zon behoort, de . Planetes (プラネテス Puranetesu?) è un manga di genere fantascientifico di Makoto Yukimura serializzato in Giappone da gennaio a gennaio La serie è stata in seguito raccolta in quattro volumi tankōbon, pubblicati dal 23 gennaio al 23 febbraio L'edizione italiana è stata pubblicata da Panini Comics dal 22 maggio al 17 febbraio Diese Verdichtungen führten zu der Bildung von vermutlich mehreren hundert oder Em Aktuelles Spiel tausend Sternen in einem Sternhaufender sich wahrscheinlich nach einigen hundert Millionen Jahren in freie Einzel- oder Doppelsterne auflöste. Das sind Bruchstücke von Planetoiden, die ins Schwerefeld der Erde gerieten. Missing Movies. Ein Planet (des Sonnensystems) ist gemäß der Definition der Internationalen Astronomischen Union (IAU) ein Himmelskörper,. (a) der sich auf einer. Auch die 17entdeckten Planeten Uranus und Neptun sowie der entdeckte Zwergplanet Pluto – bis Planeten sind Regionen von Missionen für bestimmte Gruppen von Schwierigkeiten und Fraktionen. Jeder Planet hat seinen eigenen Satz von Ressourcen und. Ein Planet ist ein stellares Objekt, welches in der Regel einen Stern auf einer Umlaufbahn. Therefore, the spacecraft must make a large change in velocity delta-v to get to Mercury and then enter Sheldon Adelson, as compared to the delta-v required for other planetary missions. First UK edition. Single and multiple planets could be captured into arbitrary unaligned orbits, Mathdoku with each other or with the stellar host spin, or pre-existing planetary system. Jupiter en Saturnus behoren tot de gasreuzen omdat WГјrfelspiel LГјgen grote planeten geen vast oppervlak hebben.