Gotthold Ephraim Lessing
Gotthold Ephraim Lessing was a German writer, dramatist and art critic, one of the most outstanding representatives of the Enlightenment era. His plays and theoretical writings influenced the development of German literature, he is considered by theatre historians to be the first dramaturg in his role at Abel Seyler's Hamburg National Theatre. Lessing was born in Kamenz, a small town in Saxony, to Johann Gottfried Lessing and Justine Salome Feller, his father wrote on theology. Young Lessing studied at the Latin School in Kamenz from 1737 to 1741. With a father who wanted his son to follow in his footsteps, Lessing next attended the Fürstenschule St. Afra in Meissen. After completing his education at St. Afra's, he enrolled at the University of Leipzig where he pursued a degree in theology, medicine and philology, it was here that his relationship with a famous German actress, began. He translated several French plays for her, his interest in theatre grew. During this time, he wrote The Young Scholar.
Neuber produced the play in 1748. From 1748 to 1760, Lessing lived in Berlin, he began to work as a editor for the Vossische Zeitung and other periodicals. Lessing formed a close connection with his cousin, Christlob Mylius, decided to follow him to Berlin. In 1750, Lessing and Mylius teamed together to begin a periodical publication named Beiträge zur Historie und Aufnahme des Theaters; the publication ran only four issues, but it caught the public's eye and revealed Lessing to be a serious critic and theorist of drama. In 1752 he took his master's degree in Wittenberg. From 1760 to 1765, he worked in Breslau as secretary to General Tauentzien during the Seven Years' War between Britain and France, which had effects in Europe, it was during this time that he wrote the Limitations of Poetry. In 1765 Lessing returned to Berlin, leaving in 1767 to work for three years at the Hamburg National Theatre. Actor-manager, Konrad Ackermann, began construction on Germany's first permanent theatre in Hamburg.
Johann Friedrich Löwen established the Hamburg National Theatre. The owners hired Lessing as the theatre's critic of plays and acting, which would be known as dramaturgy, making Lessing the first dramaturge; the theatre's main backer was Abel Seyler, a former currency speculator who since became known as "the leading patron of German theatre." There he met his future wife. His work in Hamburg formed the basis of his pioneering work on drama, titled Hamburgische Dramaturgie; because of financial losses due to pirated editions of the Hamburgische Dramaturgie, the Hamburg Theatre closed just three years later. In 1770 Lessing became librarian at the ducal library, now the Herzog August Library, in Wolfenbüttel under the commission of the Duke of Brunswick, his tenure there was energetic. In 1775, for example, he accompanied Prince Leopold to Italy. On 14 October 1771 Lessing was initiated into Freemasonry in the lodge "Zu den drei Goldenen Rosen" in Hamburg. In 1776 he married Eva König, a widow, in Jork.
She died in 1778 after giving birth to a short-lived son. On 15 February 1781, aged 52, died during a visit to the wine dealer Angott in Brunswick. Lessing was famous for his friendship with Jewish-German philosopher Moses Mendelssohn. A recent biography of Mendelssohn's grandson, describes their friendship as one of the most "illuminating metaphors the clarion call of the Enlightenment for religious tolerance", it was this relationship. He began publishing heated pamphlets on his beliefs which were banned, it was this banishment that inspired him to return to theatre to portray his views and to write Nathan the Wise. Early in his life, Lessing showed interest in the theatre. In his theoretical and critical writings on the subject—as in his own plays—he tried to contribute to the development of a new type of theatre in Germany. With this he turned against the predominant literary theory of Gottsched and his followers. Lessing's Hamburgische Dramaturgie ran critiques of plays that were performed in the Hamburg Theatre, but after dealing with dissatisfied actors and actresses, Lessing redirected his writings to more of an analysis on the proper uses of drama.
Lessing advocated the outline of drama in Aristotle's Poetics. He believed the French Academy had devalued the uses of drama through their neoclassical rules of form and separation of genres, his repeated opinions on this issue influenced theatre practitioners who began the movement of rejecting theatre rules known as Sturm und Drang. He supported serious reception of Shakespeare's works, he worked with many theatre groups. In Hamburg he tried with others to set up the German National Theatre. Today his own works appear as prototypes of the developed bourgeois German drama. Scholars see Miss Sara Sampson and Emilia Galotti as amongst the first bourgeois tragedies, Minna von Barnhelm as the model for many classic German comedies, Nathan the Wise as the first German drama of ideas, his theoretical writings Laocoön and Hamburg Dramaturgy set the standards for the discussion of aesthetic and literary theoretical principles. Lessing advocated that dramaturgs should carry their work out working directly with theatre companies
Maximilian Franz Joseph Cornelius "Max" Wolf was a German astronomer and a pioneer in the field of astrophotography. He was chairman of astronomy at the University of Heidelberg and director of the Heidelberg-Königstuhl State Observatory from 1902 until his death. Max Wolf was born in Germany on June 21, 1863, the son of medical doctor Franz Wolf, his father encouraged an interest in science and built an observatory for his son in the garden of the family home. It is from here that Wolf was credited with his first astronomical discovery, comet 14P/Wolf, in 1884. Wolf attended his local university and, in 1888, at the age of 25, was awarded a Ph. D. by the University of Heidelberg. He spent one year of post-graduate study in Stockholm, the only significant time he would spend outside of Heidelberg in his life, he returned to the University of Heidelberg and accepted the position of privat-docent in 1890. A popular lecturer in astronomy, he declined offers of positions from other institutions. In 1902 he was appointed Chair of Astronomy and Director of the new Landessternwarte Heidelberg-Königstuhl observatory, positions he would hold until his death in 1932.
While the new observatory was being built Wolf was appointed to supervise the construction and outfitting of the astrophysics half of the observatory. He proved to be not only a capable supervisor but a successful fundraiser; when sent to America to study the construction of the large new telescopes being built there he returned not only with telescope plans but with a grant of $10,000 from the American philanthropist Catherine Wolfe Bruce. Wolf designed and ordered a double refractor telescope from American astronomer and instrument builder John Brashear; this instrument, known as the Bruce double-astrograph, with parallel 16 in lenses and a fast f/5 focal ratio, became the observatory's primary research telescope. Wolf raised money for a 28 in reflector telescope, the first for the observatory, used for spectroscopy. In 1910 Wolf proposed to the Carl Zeiss optics firm the creation of a new instrument which would become known as the planetarium. World War I intervened before the invention could be developed, but the Carl Zeiss company resumed this project after peace was restored.
The first official public showing was at the Deutsches Museum in Munich, Germany on October 21, 1923. During his trip to America Wolf was interested in learning more about the new field of astrophotography, he met the American astronomer and astrophotographer E. E. Barnard, the two became lifelong correspondents, competitors and friends. Wolf wrote a long obituary for Barnard upon his death in 1923. Heidelberg University became well known for astronomy under Wolf's leadership. Wolf himself was an active researcher, contributing numerous papers in many areas of astronomy up to the end of his life, he died in Heidelberg on October 3, 1932, at the age of 69. He was survived by three sons. Wolf continued to discover them throughout his life, he co-discovered several comets, including 14P/Wolf and 43P/Wolf-Harrington. Wolf won a competition with E. E. Barnard on who would be the first to observe the return of Halley's Comet in April 1910, he discovered or co-discovered four supernovae: SN 1895A, SN 1909A, SN 1920A, with Reinmuth, SN 1926A.
One of the many significant contributions Wolf made was in the determination of the nature of dark nebulae. These areas of the sky, thought since William Herschel's time to be "holes in the sky", were a puzzle to astronomers of the time. In collaboration with E. E. Barnard, Wolf proved, by careful photographic analysis, that dark nebulae were huge clouds of fine opaque dust. Along with E. E. Barnard, Wolf applied astrophotography to the observation of stars; the Bruce double-astrograph was designed to hunt dim asteroids but it was found to be ideally suited for the study of the proper motion of low-luminosity stars using much the same technique. In 1919 Wolf published a catalog of the locations of over one thousand stars along with their measured proper motion; these stars are still identified by his name and catalog number. Among the stars he discovered is Wolf 359, a dim red dwarf, found to be one of the nearest stars to our solar system, he continued to add proper motion star discoveries to this catalog throughout his life, with the catalog totaling over 1500 stars, many more than all of his competitors combined.
These stars are significant because stars with low luminosity and high proper motion, such as Barnard's Star and Wolf 359, are relatively close to the Earth and thus the stars in Wolf's catalog remain popular subjects for astronomical research. The methods used by E. E. Barnard and Wolf were continued by Frank Elmore Ross and George Van Biesbroeck through the mid-20th century. Since that time photographic plates have been replaced with more sensitive electronic photodetectors for astronomical surveys. In 1891, Wolf discovered his first asteroid, 323 Brucia, named it after Catherine Wolfe Bruce, he pioneered the use of astrophotographic techniques to automate the discovery of asteroids, as opposed to older visual methods, as a result of which asteroid discovery rates increased. In time-exposure photographs, asteroids appear as short streaks due to their planetary motion with respect to fixed stars. Wolf discovered more than 200 asteroids in his lifetime. Among his many discoveries was 588 Achilles in 1906, as well as two other Trojans: 659 Nestor and 884 Priamus.
He discovered 887 Alinda in 1918, now recognized as an Earth-crossing Amor asteroid (or sometimes classified as
Colorado Springs, Colorado
Colorado Springs is a home rule municipality, the largest city by area in Colorado as well as the county seat and the most populous municipality of El Paso County, United States. Colorado Springs is located in the east central portion of the state, it is situated on Fountain Creek and is located 60 miles south of the Colorado State Capitol in Denver. At 6,035 feet the city stands over 1 mile above sea level, though some areas of the city are higher and lower. Colorado Springs is situated near the base of Pikes Peak, which rises 14,115 feet above sea level on the eastern edge of the Southern Rocky Mountains; the city is home to 24 national governing bodies of sport, including the United States Olympic Committee, the United States Olympic Training Center, USA Hockey. The city had an estimated population of 465,101 in 2016, a metro population of 712,000, ranking as the second most populous city in the state of Colorado, behind Denver, the 42nd most populous city in the United States; the Colorado Springs, CO Metropolitan Statistical Area had an estimated population of 712,327 in 2016.
The city is included in the Front Range Urban Corridor, an oblong region of urban population along the Front Range of the Rocky Mountains in Colorado and Wyoming following the path of Interstate 25 in both states. The city covers 194.9 square miles. In 2018, Colorado Springs received several accolades: U. S. News named Colorado Springs the number one most desirable place to live in the United States, number two on their list of the 125 Best Places to Live in the USA; the Metropolitan Policy Program at Brookings found that Colorado Springs was the fastest growing city for Millennials. Thumbtack's annual Small Business Friendliness Survey found Colorado Springs to be the number four most business friendly city in the country; the Ute and Cheyenne peoples were the first recorded inhabiting the area which would become Colorado Springs. Part of the territory included in the United States' 1803 Louisiana Purchase, the current city area was designated part of the 1854 Kansas Territory. In 1859, after the first local settlement was established, it became part of the Jefferson Territory on October 24 and of El Paso County on November 28.
Colorado City at the Front Range confluence of Fountain and Camp creeks was "formally organized on August 13, 1859" during the Pike's Peak Gold Rush. It served as the capital of the Colorado Territory from November 5, 1861, until August 14, 1862, when the capital was moved to Denver. In 1871 the Colorado Springs Company laid out the towns of La Font and Fountain Colony and downstream of Colorado City. Within a year, Fountain Colony would be renamed "Colorado Springs", was incorporated; the El Paso County seat shifted from Colorado City in 1873 to the Town of Colorado Springs. On December 1, 1880, Colorado Springs expanded northward with two annexations; the second period of annexations was during 1889–90, included Seavey's Addition, West Colorado Springs, East End, another North End addition. In 1891 the Broadmoor Land Company built the Broadmoor suburb, which included the Broadmoor Casino, by December 12, 1895, the city had "four Mining Exchanges and 275 mining brokers." By 1898, the city was designated into quadrants by the north-south Cascade Avenue and the east-west Washington/Pike's Peak avenues.
From 1899 to 1901 Tesla Experimental Station operated on Knob Hill, aircraft flights to the Broadmoor's neighboring fields began in 1919. Alexander Airport north of the city opened in 1925, in 1927 the original Colorado Springs Municipal Airport land was purchased east of the city. In World War II the United States Army Air Forces leased land adjacent to the municipal airfield, naming it "Peterson Field" in December 1942; this was only one of several military presences around Colorado Springs during the war. In November 1950, Ent Air Force Base was selected as the Cold War headquarters for Air Defense Command; the former WWII Army Air Base, Peterson Field, inactivated at the end of the war, was re-opened in 1951 as a U. S. Air Force base; the 1950s through 1970s saw a continued expansion of the military presence in the area, with the establishment of NORAD's headquarters in the city, as well as the ADCOM headquarters. Between 1965 and 1968, the University of Colorado Colorado Springs, Pikes Peak Community College and Colorado Technical University were established in or near the city.
In 1977 most of the former Ent AFB became a US Olympic training center. The Libertarian Party was founded within the city in the 1970s. On October 1, 1981, the Broadmoor Addition, Cheyenne Canon, Ivywild and Stratton Meadows were annexed after the Colorado Supreme Court "overturned a district court decision that voided the annexation". Further annexations expanding the city include the Nielson Addition and Vineyard Commerce Park Annexation in September 2008; the city lies in a high desert with the Southern Rocky Mountains to the west, the Palmer Divide to the north, high plains further east, high desert lands to the south when leaving Fountain and approaching Pueblo. According to the United States Census Bureau, the city has a total area of 194.6 square miles, of which 194.6 square miles is land and 0.35 square miles, or 0.19%, is water. Colorado Springs has many features of a modern urban area, such as parks, bike trails, urban open-area spaces. However, it is not exempt from problems that plague cities that experience tremendous growth, such as overcrowded roads and highways, crime and government budget issues.
Many of the problems are indirec
Rebekka is a minor planet orbiting the Sun, discovered on September 19, 1905, by a German astronomer Paul Götz in Heidelberg. It was named after a young lady from Heidelberg. Observations performed at the Palmer Divide Observatory in Colorado Springs, Colorado during 2007 produced a light curve with a period of 5.656 ± 0.002 hours with a brightness range of 0.40 ± 0.02 in magnitude. This agrees with the 5.65 hour period measured in 1998. Lightcurve plot of 572 Rebekka, Palmer Divide Observatory, B. D. Warner Asteroid Lightcurve Database, query form Dictionary of Minor Planet Names, Google books Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend Discovery Circumstances: Numbered Minor Planets - – Minor Planet Center 572 Rebekka at the JPL Small-Body Database Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters
A day is the period of time during which the Earth completes one rotation around its axis. A solar day is the length of time which elapses between the Sun reaching its highest point in the sky two consecutive times. In 1960, the second was redefined in terms of the orbital motion of the Earth in year 1900, was designated the SI base unit of time; the unit of measurement "day", was symbolized d. In 1967, the second and so the day were redefined by atomic electron transition. A civil day is 86,400 seconds, plus or minus a possible leap second in Coordinated Universal Time, plus or minus an hour in those locations that change from or to daylight saving time. Day can be defined as each of the twenty-four-hour periods, reckoned from one midnight to the next, into which a week, month, or year is divided, corresponding to a rotation of the earth on its axis; however its use depends on its context, for example when people say'day and night','day' will have a different meaning. It will mean the interval of light between two successive nights.
However, in order to be clear when using'day' in that sense, "daytime" should be used to distinguish it from "day" referring to a 24-hour period. The word day may refer to a day of the week or to a calendar date, as in answer to the question, "On which day?" The life patterns of humans and many other species are related to Earth's solar day and the day-night cycle. Several definitions of this universal human concept are used according to context and convenience. Besides the day of 24 hours, the word day is used for several different spans of time based on the rotation of the Earth around its axis. An important one is the solar day, defined as the time it takes for the Sun to return to its culmination point; because celestial orbits are not circular, thus objects travel at different speeds at various positions in their orbit, a solar day is not the same length of time throughout the orbital year. Because the Earth orbits the Sun elliptically as the Earth spins on an inclined axis, this period can be up to 7.9 seconds more than 24 hours.
In recent decades, the average length of a solar day on Earth has been about 86 400.002 seconds and there are about 365.2422 solar days in one mean tropical year. Ancient custom has a new day start at either the setting of the Sun on the local horizon; the exact moment of, the interval between, two sunrises or sunsets depends on the geographical position, the time of year. A more constant day can be defined by the Sun passing through the local meridian, which happens at local noon or midnight; the exact moment is dependent on the geographical longitude, to a lesser extent on the time of the year. The length of such a day is nearly constant; this is the time as indicated by modern sundials. A further improvement defines a fictitious mean Sun that moves with constant speed along the celestial equator. A day, understood as the span of time it takes for the Earth to make one entire rotation with respect to the celestial background or a distant star, is called a stellar day; this period of rotation is about 4 minutes less than 24 hours and there are about 366.2422 stellar days in one mean tropical year.
Other planets and moons have solar days of different lengths from Earth's. A day, in the sense of daytime, distinguished from night time, is defined as the period during which sunlight directly reaches the ground, assuming that there are no local obstacles; the length of daytime averages more than half of the 24-hour day. Two effects make daytime on average longer than nights; the Sun has an apparent size of about 32 minutes of arc. Additionally, the atmosphere refracts sunlight in such a way that some of it reaches the ground when the Sun is below the horizon by about 34 minutes of arc. So the first light reaches the ground when the centre of the Sun is still below the horizon by about 50 minutes of arc. Thus, daytime is on average around 7 minutes longer than 12 hours; the term comes from the Old English dæg, with its cognates such as dagur in Icelandic, Tag in German, dag in Norwegian, Danish and Dutch. All of them from the Indo-European root dyau which explains the similarity with Latin dies though the word is known to come from the Germanic branch.
As of October 17, 2015, day is the 205th most common word in US English, the 210th most common in UK English. A day, symbol d, defined as 86 400 seconds, is not an SI unit, but is accepted for use with SI; the Second is the base unit of time in SI units. In 1967–68, during the 13th CGPM, the International Bureau of Weights and Measures redefined a second as … the duration of 9 192 631 770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium 133 atom; this makes the SI-based day last 794 243 384 928 000 of those periods. Due to tidal effects, the
The kilometre, or kilometer is a unit of length in the metric system, equal to one thousand metres. It is now the measurement unit used for expressing distances between geographical places on land in most of the world. K is used in some English-speaking countries as an alternative for the word kilometre in colloquial writing and speech. A slang term for the kilometre in the US and UK military is klick. There are two common pronunciations for the word; the former follows a pattern in English whereby metric units are pronounced with the stress on the first syllable and the pronunciation of the actual base unit does not change irrespective of the prefix. It is preferred by the British Broadcasting Corporation and the Australian Broadcasting Corporation. Many scientists and other users in countries where the metric system is not used, use the pronunciation with stress on the second syllable; the latter pronunciation follows the stress pattern used for the names of measuring instruments. The problem with this reasoning, however, is that the word meter in those usages refers to a measuring device, not a unit of length.
The contrast is more obvious in countries using the British rather than American spelling of the word metre. When Australia introduced the metric system in 1975, the first pronunciation was declared official by the government's Metric Conversion Board. However, the Australian prime minister at the time, Gough Whitlam, insisted that the second pronunciation was the correct one because of the Greek origins of the two parts of the word. By the 8 May 1790 decree, the Constituent assembly ordered the French Academy of Sciences to develop a new measurement system. In August 1793, the French National Convention decreed the metre as the sole length measurement system in the French Republic; the first name of the kilometre was "Millaire". Although the metre was formally defined in 1799, the myriametre was preferred to the "kilometre" for everyday use; the term "myriamètre" appeared a number of times in the text of Develey's book Physique d'Emile: ou, Principes de la science de la nature, while the term kilometre only appeared in an appendix.
French maps published in 1835 had scales showing myriametres and "lieues de Poste". The Dutch gave it the local name of the mijl, it was only in 1867 that the term "kilometer" became the only official unit of measure in the Netherlands to represent 1000 metres. Two German textbooks dated 1842 and 1848 give a snapshot of the use of the kilometre across Europe - the kilometre was in use in the Netherlands and in Italy and the myriametre was in use in France. In 1935, the International Committee for Weights and Measures abolished the prefix "myria-" and with it the "myriametre", leaving the kilometre as the recognised unit of length for measurements of that magnitude. In the United Kingdom, road signs show distances in miles and location marker posts that are used for reference purposes by road engineers and emergency services show distance references in unspecified units which are kilometre-based; the advent of the mobile phone has been instrumental in the British Department for Transport authorising the use of driver location signs to convey the distance reference information of location marker posts to road users should they need to contact the emergency services.
In the US, the National Highway System Designation Act of 1995 prohibits the use of federal-aid highway funds to convert existing signs or purchase new signs with metric units. The Executive Director of the US Federal Highway Administration, Jeffrey Paniati, wrote in a 2008 memo: "Section 205 of the National Highway System Designation Act of 1995 prohibited us from requiring any State DOT to use the metric system during project development activities. Although the State DOT's had the option of using metric measurements or dual units, all of them abandoned metric measurements and reverted to sole use of inch-pound values." The Manual on Uniform Traffic Control Devices since 2000 is published in both metric and American Customary Units. Some sporting disciplines feature 1000 m races in major events, but in other disciplines though world records are catalogued, the one kilometre event remains a minority event; the world records for various sporting disciplines are: Conversion of units, for comparison with other units of length Cubic metre Metric prefix Mileage Odometer Orders of magnitude Square kilometre Media related to Distance indicators at Wikimedia Commons
Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a giant planet with a mass one-thousandth that of the Sun, but two-and-a-half times that of all the other planets in the Solar System combined. Jupiter and Saturn are gas giants. Jupiter has been known to astronomers since antiquity, it is named after the Roman god Jupiter. When viewed from Earth, Jupiter can reach an apparent magnitude of −2.94, bright enough for its reflected light to cast shadows, making it on average the third-brightest natural object in the night sky after the Moon and Venus. Jupiter is composed of hydrogen with a quarter of its mass being helium, though helium comprises only about a tenth of the number of molecules, it may have a rocky core of heavier elements, but like the other giant planets, Jupiter lacks a well-defined solid surface. Because of its rapid rotation, the planet's shape is that of an oblate spheroid; the outer atmosphere is visibly segregated into several bands at different latitudes, resulting in turbulence and storms along their interacting boundaries.
A prominent result is the Great Red Spot, a giant storm, known to have existed since at least the 17th century when it was first seen by telescope. Surrounding Jupiter is a powerful magnetosphere. Jupiter has 79 known moons, including the four large Galilean moons discovered by Galileo Galilei in 1610. Ganymede, the largest of these, has a diameter greater than that of the planet Mercury. Jupiter has been explored on several occasions by robotic spacecraft, most notably during the early Pioneer and Voyager flyby missions and by the Galileo orbiter. In late February 2007, Jupiter was visited by the New Horizons probe, which used Jupiter's gravity to increase its speed and bend its trajectory en route to Pluto; the latest probe to visit the planet is Juno, which entered into orbit around Jupiter on July 4, 2016. Future targets for exploration in the Jupiter system include the probable ice-covered liquid ocean of its moon Europa. Astronomers have discovered nearly 500 planetary systems with multiple planets.
These systems include a few planets with masses several times greater than Earth's, orbiting closer to their star than Mercury is to the Sun, sometimes Jupiter-mass gas giants close to their star. Earth and its neighbor planets may have formed from fragments of planets after collisions with Jupiter destroyed those super-Earths near the Sun; as Jupiter came toward the inner Solar System, in what theorists call the grand tack hypothesis, gravitational tugs and pulls occurred causing a series of collisions between the super-Earths as their orbits began to overlap. Researchers from Lund University found that Jupiter's migration went on for around 700,000 years, in a period 2-3 million years after the celestial body started its life as an ice asteroid far from the sun; the journey inwards in the solar system followed a spiraling course in which Jupiter continued to circle around the sun, albeit in an tight path. The reason behind the actual migration relates to gravitational forces from the surrounding gases in the solar system.
Jupiter moving out of the inner Solar System would have allowed the formation of inner planets, including Earth. Jupiter is composed of gaseous and liquid matter, it is the largest of hence its largest planet. It has a diameter of 142,984 km at its equator; the average density of Jupiter, 1.326 g/cm3, is the second highest of the giant planets, but lower than those of the four terrestrial planets. Jupiter's upper atmosphere is about 88–92% hydrogen and 8–12% helium by percent volume of gas molecules. A helium atom has about four times as much mass as a hydrogen atom, so the composition changes when described as the proportion of mass contributed by different atoms. Thus, Jupiter's atmosphere is 75% hydrogen and 24% helium by mass, with the remaining one percent of the mass consisting of other elements; the atmosphere contains trace amounts of methane, water vapor and silicon-based compounds. There are traces of carbon, hydrogen sulfide, oxygen and sulfur; the outermost layer of the atmosphere contains crystals of frozen ammonia.
The interior contains denser materials—by mass it is 71% hydrogen, 24% helium, 5% other elements. Through infrared and ultraviolet measurements, trace amounts of benzene and other hydrocarbons have 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, about a tenth as abundant as in the Sun. Helium is depleted to about 80% of the Sun's helium composition; 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 less hydrogen and helium and more ices and are thus now termed ice giants. Jupiter's mass is 2.5 times that of all the other planets in the Solar System combined—this is so massive that its barycenter with the Sun lies above the Sun's surface at 1.068 solar radii from the Sun's center.
Jupiter is much larger than Earth and less dense: its volume is that of about 1,321 Earths, but it is only 318 times as massive. Jupiter's radius is about 1/10 the radius of the Sun, its mass is 0.001 times the mass of the Sun, so the densities of the two bodies are similar. A "Jupiter mass" is used as a u