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## KEPLER 22b

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**KEPLER 22b**Kepler 22b**Kepler´s Life: A Review**Johannes Kepler was born as child of protestant parents. He had six siblings, three of which died already at an early age. His father Heinrich Kepler, a learned merchant, hired out as mercenary soldier and scarcely was at home. When being a child Johannes fell ill with pocks, as a result of which he suffered from an eye illness and scars. In 1576 the family moved to Leonberg where Johannes attended first the German School and then the Latin School. In 1583 he passed the exam in Stuttgart and in 1584 he went to seminar Adelberg, a convent school. Two years later he was accepted at a higher seminar in Maulbronn, also a convent school. Made possible through a scholarship he began in 1589 with his studies in theology at the University of Tübingen.**At this university also Michael Maestlin (1550–1631) was a**teacher. He was professor for mathematics and astronomy and fought for spreading the Copernican theory. In this theory not the earth but the sun is at the centre of the solar system (heliocentric world view). In TuebingenKepler had first contacts with the heliocentric world view because he had discovered his liking for astronomy and mathematics. Kepler became a passionate believer. In 1591 he made his master’s degree successfully and continued his theological studies. In 1594 shortly before finishing his studies, he went to Graz to work there as landscape mathematician and teacher for mathematics. In Graz the task of a landscape mathematician was to write astrological calendars. Kepler was very good in it and became quickly famous through his horoscopes. He continued to study mathematics and was busy with astronomical problems. In 1596 he published Mysteriumcosmographicum, his first work on astronomy. The deeply religious Kepler was convinced that “the world” is built harmonically by the creator god.**Assistant to Tycho Brahe**In April 1597 he married Barbara Mueller. In the course of the counter-reformation in September 1598, all protestant clerics and teachers were driven out of Styria. Kepler had to leave the country. After some interim stops, he went in 1600 to the mathematician and court astronomer Tycho Brahe (1546–1601) in Prague. Tycho Brahe was working for Emperor Rudolf II and had both the most exact empiric data and the most exact measuring instruments of his time. Kepler was assistant of Brahe and there he saw the possibility to test his astronomical theories empirically. As Brahe was more convinced of the geocentric world view and Kepler more of the heliocentric one their teamwork was disturbed. In the geocentric world view the earth, and not the sun is at the centre of the solar system. The deeply different characters of the two men added to this conflict. Thus for Kepler it was really difficult to get Brahe’s observation data, which were important for his work.**Planetary Motion**Brahe and Kepler together began the work about new, exact planet tables (Rudolfinian tables). Brahe set Kepler also the task to define the motion of the planet Mars. Astronomical observations had produced that the motion of Mars differed from a circle. This task was godsend for Kepler as he here, in the course of his thoughts, put the circular motion of planets into question and thought about elliptic ones. But this work was to keep him busy for some more years. In 1601, after the death of Tycho Brahe, Kepler became imperial mathematician. Now Brahe’s astronomical observation data and his measuring instruments were at his disposal. In 1604 he wrote a report on a supernova watched by himself and worked on the Astronomia nova in which he wrote down his results about the orbit of planet Mars. In 1609 this work was published. In it are Kepler’s first two laws of planetary motion.**Johannes Kepler, about 1620. This portrait was hung up in**the library of the University of Strasbourg in 1627.**Kepler and the Reformation**In October 1613 he married his second wife, Mrs Susanne Reuttinger. In Linz Kepler worked still on the Rudolfinian tables. In his world harmony with which he also worked in Linz, Kepler searched for a harmonic model of the universe. He worked out the theoretical basics of music. In July 1619 he published his results concerning the world harmony in a five-volume book. It was called Harmonices mundi. The fifth volume contained Kepler’s Third Law of Planetary Motion. In Linz he completed two more works: the Epitome astronomiaecopernicanaeand the TabulaeRudolphinae. In 1615 Kepler’s mother Katharina was accused of wizardry in Leonberg. Kepler himself defended her. But it took six years until she was absolved. In 1618 the Thirty Years’ War had begun.**Kepler´s First Law**1609: ASTRONOMIA NOVA Keplerwas the first to rejected the complete circular motion in his tests on planetary motion. Only with the observation of elliptic orbits did he find the long looked for accordance with Tycho Brahe’s measured data.**Kepler´s Second Law**1609: ASTRONOMIA NOVA ”A line joining a planet and the Sun sweeps out equal areas during equal intervals of time.” http://en.wikipedia.org/wiki/Kepler's_laws_of_planetary_motion#Third_law**”The square of the orbital period of a planet is directly**proportional to the cube of the semi-major axis of its orbit.” The third law, published by Kepler in 1619 [1] captures the relationship between the distance of planets from the Sun, and their orbital periods. For example, suppose planet A is 4 times as far from the Sun as planet B. Then planet A must traverse 4 times the distance of Planet B each orbit, and moreover it turns out that planet A travels at half the speed of planet B, in order to maintain equilibrium with the reduced gravitational centripetal force due to being 4 times further from the Sun. In total it takes 4×2=8 times as long for planet A to travel an orbit, in agreement with the law (82=43). This third law used to be known as the harmonic law,[8] because Kepler enunciated it in a laborious attempt to determine what he viewed as the "music of the spheres" according to precise laws, and express it in terms of musical notation.[9] This third law currently receives additional attention as it can be used to estimate the distance from an exoplanet to its central star, and help to decide if this distance is inside the habitable zone of that star.**Kepler left Linz with his family in 1626 because of the**pressure of the counter-reformation and went to Ulm. There he finished his work on the Rudolfinian tables which were printed in 1627 (TabulaeRudolphinae). To facilitate the commerce he received in Ulm also the order to determine new measuring units. In the year 1628 he went to the Silesian town Sagan to work there as mathematician for his protégé Albrecht von Wallenstein (1583–1634). On November 15, 1630 when being in Regensburg Johannes Kepler died. He was next to Galileo Galilei and Isaac Newton (1643–1727) one of the most important natural scientists of modern times. His grave in Regensburg was destroyed a few years later in the disturbances of the Thirty Years’ War.**Potential Planets**"We're getting closer and closer to discovering the so-called 'Goldilocks planet,'" said Pete Worden, director of NASA's Ames Research Center, according to Space.com, referring to a habitable planet that is "just right" in meeting all the requirements for life. Kepler-22b is pleasantly warm, with an average surface temperature of 72 degrees Fahrenheit, according to researchers. It orbits its star at the right distance for liquid water to exist.**The Kepler spacecraft has discovered 2,326 potential planets**just 16 months into its planet-hunting mission. If those discoveries are confirmed, it brings the total number of planets scientists have discovered outside of our solar system to four times the 700 or so that were known to exist prior to Kepler's mission. Kepler was launched in March 2009. The $600 million space observatory looks for small changes in a star's brightness that indicate a planet is transiting the star from the spacecraft's vantage point. The spacecraft then sends its data back to Earth, where scientists conduct follow-up observations to determine if the candidate planets Kepler has observed are the real deal. Only about two dozen Kepler-discovered planets have been confirmed so far, but researchers say about 80 percent of the spacecraft's positive hits should wind up passing muster as planets.**Of the more than 2,000 candidate planets Kepler has**discovered nearly 700 are larger than Earth, while 207 are about the same size as our home planet. The confirmation of planet status for Kepler-22b is almost certainly just the start for researchers—the Kepler spacecraft has also sent back data on nearly 50 more candidate planets that orbit within the habitable zones of their stars. Back in September, data from the Kepler mission uncovered evidence of a circumbinary planet, or a planet that orbits two stars, which is reminiscent of Tatooine, the planet on which Star Wars character Luke Skywalker grew up.