Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System after Mercury. In English, Mars carries a name of the Roman god of war, is referred to as the "Red Planet" because the reddish iron oxide prevalent on its surface gives it a reddish appearance, distinctive among the astronomical bodies visible to the naked eye. Mars is a terrestrial planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the valleys and polar ice caps of Earth; the days and seasons are comparable to those of Earth, because the rotational period as well as the tilt of the rotational axis relative to the ecliptic plane are similar. Mars is the site of Olympus Mons, the largest volcano and second-highest known mountain in the Solar System, of Valles Marineris, one of the largest canyons in the Solar System; the smooth Borealis basin in the northern hemisphere covers 40% of the planet and may be a giant impact feature. Mars has two moons and Deimos, which are small and irregularly shaped.
These may be captured asteroids, similar to a Mars trojan. There are ongoing investigations assessing the past habitability potential of Mars, as well as the possibility of extant life. Future astrobiology missions are planned, including the Mars 2020 and ExoMars rovers. Liquid water cannot exist on the surface of Mars due to low atmospheric pressure, less than 1% of the Earth's, except at the lowest elevations for short periods; the two polar ice caps appear to be made of water. The volume of water ice in the south polar ice cap, if melted, would be sufficient to cover the entire planetary surface to a depth of 11 meters. In November 2016, NASA reported finding a large amount of underground ice in the Utopia Planitia region of Mars; the volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior. Mars can be seen from Earth with the naked eye, as can its reddish coloring, its apparent magnitude reaches −2.94, surpassed only by Jupiter, the Moon, the Sun.
Optical ground-based telescopes are limited to resolving features about 300 kilometers across when Earth and Mars are closest because of Earth's atmosphere. Mars is half the diameter of Earth with a surface area only less than the total area of Earth's dry land. Mars is less dense than Earth, having about 15% of Earth's volume and 11% of Earth's mass, resulting in about 38% of Earth's surface gravity; the red-orange appearance of the Martian surface is caused by rust. It can look like butterscotch. Like Earth, Mars has differentiated into a dense metallic core overlaid by less dense materials. Current models of its interior imply a core with a radius of about 1,794 ± 65 kilometers, consisting of iron and nickel with about 16–17% sulfur; this iron sulfide core is thought to be twice as rich in lighter elements as Earth's. The core is surrounded by a silicate mantle that formed many of the tectonic and volcanic features on the planet, but it appears to be dormant. Besides silicon and oxygen, the most abundant elements in the Martian crust are iron, aluminum and potassium.
The average thickness of the planet's crust is about 50 km, with a maximum thickness of 125 km. Earth's crust averages 40 km. Mars is a terrestrial planet that consists of minerals containing silicon and oxygen and other elements that make up rock; the surface of Mars is composed of tholeiitic basalt, although parts are more silica-rich than typical basalt and may be similar to andesitic rocks on Earth or silica glass. Regions of low albedo suggest concentrations of plagioclase feldspar, with northern low albedo regions displaying higher than normal concentrations of sheet silicates and high-silicon glass. Parts of the southern highlands include detectable amounts of high-calcium pyroxenes. Localized concentrations of hematite and olivine have been found. Much of the surface is covered by finely grained iron oxide dust. Although Mars has no evidence of a structured global magnetic field, observations show that parts of the planet's crust have been magnetized, suggesting that alternating polarity reversals of its dipole field have occurred in the past.
This paleomagnetism of magnetically susceptible minerals is similar to the alternating bands found on Earth's ocean floors. One theory, published in 1999 and re-examined in October 2005, is that these bands suggest plate tectonic activity on Mars four billion years ago, before the planetary dynamo ceased to function and the planet's magnetic field faded, it is thought that, during the Solar System's formation, Mars was created as the result of a stochastic process of run-away accretion of material from the protoplanetary disk that orbited the Sun. Mars has many distinctive chemical features caused by its position in the Solar System. Elements with comparatively low boiling points, such as chlorine and sulphur, are much more common on Mars than Earth. After the formation of the planets, all were subjected to the so-called "Late Heavy Bombardment". About 60% of the surface of Mars shows a record of impacts from that era, whereas much of the remaining surface is underlain by immense impact basins caused by those events.
There is evidence of an enormous impact basin in the northern hemisphere of Mars, spanning 10,600 by 8,500 km, or four times the size of the Moon's South Pole – Aitk
The Outer Limits (1963 TV series)
The Outer Limits is an American television series, broadcast on ABC from 1963 to 1965 at 7:30 PM Eastern Time on Mondays. The series is compared to The Twilight Zone, but with a greater emphasis on science fiction stories; the Outer Limits is an anthology of self-contained episodes, sometimes with a plot twist at the end. The series was revived in 1995, airing on Showtime from 1995 to 2000 on Sci-Fi Channel from 2001 until its cancellation in 2002. In 1997, the episode "The Zanti Misfits" was ranked #98 on TV Guide's 100 Greatest Episodes of All Time. A new revival is in the works at a premium cable network; each show would begin with either a cold open or a preview clip, followed by a "Control Voice" narration, run over visuals of an oscilloscope. Using an Orwellian theme of taking over your television, the earliest version of the narration ran as follows: A similar but shorter monolog caps each episode: We now return control of your television set to you; until next week at the same time, when the control voice will take you to – The Outer Limits.
Episodes used one of two shortened versions of the introduction. The first few episodes began with the title screen followed by the narration and no cold open or preview clip; the Control Voice was performed by actor Vic Perrin. The Outer Limits was broadcast on the American television network ABC. In total, 49 episodes were produced, it was one of many series influenced by The Twilight Zone and Science Fiction Theatre, though it proved influential in its own right. In the un-aired pilot, the series was called Please Stand By. Series creator Leslie Stevens retitled it The Outer Limits. With a few changes, the pilot aired as the premiere episode, "The Galaxy Being". Writers for The Outer Limits included creator Stevens and Joseph Stefano, the Season 1 producer and creative guiding force. Stefano wrote more episodes of the show than any other writer. Future Oscar-winning screenwriter Robert Towne wrote "The Chameleon", the final episode filmed for Season 1. Two notable Season 2 episodes "Demon with a Glass Hand" and "Soldier" were written by Harlan Ellison, with the former episode winning a Writers' Guild Award.
The former was for several years the only episode of The Outer Limits available on LaserDisc. Season 1 combined science-fiction and horror, while Season 2 was more focused on'hard science fiction' stories, dropping the recurring "scary monster" motif of Season 1; each show in Season 1 was to have a creature as a critical part of the story line. Season 1 writer and producer Joseph Stefano believed that this element was necessary to provide fear, suspense, or at least a center for plot development; this kind of story element became known as "the bear". This device was, however dropped in Season 2 when Stefano left; the "bear" in "The Architects of Fear", the monstrously altered Allen Leighton, was judged by some of ABC's local affiliate stations to be so frightening that they broadcast a black screen during the "Thetan's" appearances censoring most of the show's last act. In other parts of the United States, the "Thetan" footage was tape-delayed until after the 11pm/10c news. In others, it was not shown at all.
Season 1 had music by Dominic Frontiere. Like The Twilight Zone, The Outer Limits had an opening and closing narration in every episode. Both shows differed in style; the Twilight Zone stories were like parables, employing whimsy or irony, or extraordinary problem-solving situations. The Outer Limits was a straight action-and-suspense show which had the human spirit in confrontation with dark existential forces from within or without, such as in the alien abduction episode "A Feasibility Study" or the alien possession story "The Invisibles"; as well, The Outer Limits was known for its moody, textured look in many episodes whereas The Twilight Zone tended to be shot more conventionally. However, there is some common ground between certain episodes of the two shows; as Schow & Frentzen, the authors of The Outer Limits: The Official Companion, have noted, several Outer Limits episodes are misremembered by casual fans as having been Twilight Zone episodes, notably such "problem solving" episodes as "Fun and Games" or "The Premonition".
The program sometimes made use of techniques associated with film noir or German Expressionism (see for exa
Where Is Everybody?
"Where Is Everybody?" is the first episode of the American anthology television series The Twilight Zone. It was broadcast on October 2, 1959 on CBS. A man finds himself alone on a dirt road dressed in a U. S. Air Force flight suit, having no memory of how he got there, he finds a diner and walks in to find a jukebox playing loudly and a hot pot of coffee on the stove, but there are no other people besides himself. He accidentally breaks a clock, upon which the jukebox stops playing; the man walks toward a nearby town. Like the diner, the rest of the town seems deserted, but the man seems to find evidence of someone being there recently; the man grows unsettled as he wanders through the empty town, needing someone to talk to but at the same time feeling that he is being watched. In a soda shop, the man notices an entire spinning rack of paperback books titled The Last Man on Earth, Feb. 1959. As night falls, the lights in the park turn on, leading the man to a movie theater, the marquee of, illuminated.
He remembers he is an Air Force soldier from Battle Hymn. When the film begins onscreen, he runs to the projection booth and finds nobody there becomes more paranoid that he is being watched. Running through the streets in a panic, the man hits a pedestrian call button; the call button is revealed to be a panic button: the man, whose name is given as Sgt. Mike Ferris, is in an isolation booth being observed by a group of uniformed servicemen, he has been undergoing tests to determine his fitness as an astronaut and whether he can handle a prolonged trip to the Moon alone, though the town was a hallucination caused by sensory deprivation. The officiating general warns Ferris that while his basic needs will be provided for in space travel, he will not have companionship: "next time be alone". Ferris is carried from the hangar on a stretcher as he tells the Moon in the sky not to "go away up there", reminding himself of the loneliness he faces. Earl Holliman as Mike Ferris James Gregory as General Garry Walberg as Colonel Serling's original pilot for The Twilight Zone was "The Happy Place", which revolved around a society in which people were executed upon reaching the age of 60, being considered no longer useful.
CBS executive William Self rejected the story, feeling it was too dark. Unlike other episodes, which were filmed at Metro-Goldwyn-Mayer, "Where is Everybody?" was filmed at Universal. The episode featured Westbrook Van Voorhis as narrator; when Voorhis was unavailable for episodes, Serling re-recorded the narration himself for consistency. Serling notably changed the opening narration to place the Twilight Zone within the fifth dimension, among other alterations. Serling adapted "Where is Everybody?" for a novelization titled Stories From the Twilight Zone. Serling grew dissatisfied with the lack of science fiction content and changed the story to include Ferris discovering a movie ticket in his pocket while on the stretcher. A variation on this plotline was used in the episode "King Nine Will Not Return"; the New York Times praised the episode, saying that Serling proved "that science cannot foretell what may be the effect of total isolation on a human being", though " resolution... seemed trite and anticlimactic.
In the desultory field of filmed half-hour drama, however, Mr. Serling should not have much trouble in making his mark. At least his series promises to be different. Charles Beaumont praised the episode in The Magazine of Fantasy and Science-Fiction, writing that he "read Serling's first script... Old stuff? Of course. I thought so at the time... but there was one element in the story which kept me from my customary bitterness. The element was quality. Quality shone on every page, it shone in the scene set-ups. And because of this, the story seemed new and powerful. There was one compromise, but it was made for the purpose of selling the series." DeVoe, Bill.. Trivia from The Twilight Zone. Albany, GA: Bear Manor Media. ISBN 978-1-59393-136-0 Grams, Martin.. The Twilight Zone: Unlocking the Door to a Television Classic. Churchville, MD: OTR Publishing. ISBN 978-0-9703310-9-0 Full video of the episode at CBS.com "Where Is Everybody?" on IMDb "Where Is Everybody?" at TV.com
The word diorama can either refer to a 19th-century mobile theatre device, or, in modern usage, a three-dimensional full-size or miniature model, sometimes enclosed in a glass showcase for a museum. Dioramas are built by hobbyists as part of related hobbies such as military vehicle modeling, miniature figure modeling, or aircraft modeling; the word "diorama" originated in 1823 as a type of picture-viewing device, from the French in 1822. The word means "through that, seen", from the Greek di- "through" + orama "that, seen, a sight"; the diorama was invented by Louis Daguerre and Charles Marie Bouton, first exhibited in Paris in July 1822 and in London on September 29, 1823. The meaning "small-scale replica of a scene, etc." is from 1902. Daguerre's and Bouton's diorama consisted of a piece of material painted on both sides; when illuminated from the front, the scene would be shown in one state and by switching to illumination from behind another phase or aspect would be seen. Scenes in daylight changed to moonlight, a train travelling on a track would crash, or an earthquake would be shown in before and after pictures.
The current, popular understanding of the term "diorama" denotes a three-dimensional, full-size replica or scale model of a landscape showing historical events, nature scenes or cityscapes, for purposes of education or entertainment. One of the first uses of dioramas in a museum was in Stockholm, where the Biological Museum opened in 1893, it had several dioramas, over three floors. They were implemented by the National Museum Grigore Antipa from Bucharest Romania and constituted a source of inspiration for many important museums in the world. Miniature dioramas are much smaller, use scale models and landscaping to create historical or fictional scenes; such a scale model-based diorama is used, for example, in Chicago's Museum of Science and Industry to display railroading. This diorama employs a common model railroading scale of 1:87. Hobbyist dioramas use scales such as 1:35 or 1:48. An early, exceptionally large example was created between 1830 and 1838 by a British Army officer. William Siborne, represents the Battle of Waterloo at about 7.45 pm, on 18 June, 1815.
The diorama used around 70,000 model soldiers in its construction. It is now part of the collection of the National Army Museum in London. Sheperd Paine, a prominent hobbyist, popularized the modern miniature diorama beginning in the 1970s. Modern museum dioramas may be seen in most major natural-history museums; these displays use a tilted plane to represent what would otherwise be a level surface, incorporate a painted background of distant objects, employ false perspective modifying the scale of objects placed on the plane to reinforce the illusion through depth perception in which objects of identical real-world size placed farther from the observer appear smaller than those closer. The distant painted background or sky will be painted upon a continuous curved surface so that the viewer is not distracted by corners, seams, or edges. All of these techniques are means of presenting a realistic view of a large scene in a compact space. A photograph or single-eye view of such a diorama can be convincing, since in this case there is no distraction by the binocular perception of depth.
Miniature dioramas may be used to represent scenes from historic events. A typical example of this type are the dioramas to be seen at Norway's Resistance Museum in Oslo, Norway. Landscapes built around model railways can be considered dioramas though they have to compromise scale accuracy for better operating characteristics. Hobbyists build dioramas of historical or quasi-historical events using a variety of materials, including plastic models of military vehicles, ships or other equipment, along with scale figures and landscaping. In the 19th and beginning 20th century, building dioramas of sailing ships had been a popular handcraft of mariners. Building a diorama instead of a normal model had the advantage that in the diorama, the model was protected inside the framework and could be stowed below the bunk or behind the sea chest. Nowadays, such antique sailing ship dioramas are valuable collectors' items. One of the largest dioramas created was a model of the entire State of California built for the Panama-Pacific International Exposition of 1915 and that for a long time was installed in San Francisco's Ferry Building.
Dioramas are used in the American educational system in elementary and middle schools. They are made to represent historical events, ecological biomes, cultural scenes, or to visually depict literature, they are made from a shoebox and contain a trompe-l'œil in the background contrasted with two or three-dimensional models in the foreground. The Diorama was a popular entertainment that originated in Paris in 1822. An alternative to the popular "Panorama", the Diorama was a theatrical experience viewed by an audience in a specialized theatre; as many as 350 patrons would file in to view a landscape painting that would change its appearance both subtly and dramatically. Most would stand; the show lasted 10 to 15 minutes, after which time the entire audience would rotate to view a second painting. Models of the Diorama theater held a third painting; the size of the proscenium was 24 feet wide by 21 feet high. Each scene was hand-painted on linen, made transparent in selected areas. A ser
A rocket is a missile, aircraft or other vehicle that obtains thrust from a rocket engine. Rocket engine exhaust is formed from propellant carried within the rocket before use. Rocket engines work by action and reaction and push rockets forward by expelling their exhaust in the opposite direction at high speed, can therefore work in the vacuum of space. In fact, rockets work more efficiently in space than in an atmosphere. Multistage rockets are capable of attaining escape velocity from Earth and therefore can achieve unlimited maximum altitude. Compared with airbreathing engines, rockets are lightweight and powerful and capable of generating large accelerations. To control their flight, rockets rely on momentum, auxiliary reaction engines, gimballed thrust, momentum wheels, deflection of the exhaust stream, propellant flow, spin, or gravity. Rockets for military and recreational uses date back to at least 13th-century China. Significant scientific and industrial use did not occur until the 20th century, when rocketry was the enabling technology for the Space Age, including setting foot on the Earth's moon.
Rockets are now used for fireworks, ejection seats, launch vehicles for artificial satellites, human spaceflight, space exploration. Chemical rockets are the most common type of high power rocket creating a high speed exhaust by the combustion of fuel with an oxidizer; the stored propellant can be a simple pressurized gas or a single liquid fuel that disassociates in the presence of a catalyst, two liquids that spontaneously react on contact, two liquids that must be ignited to react, a solid combination of fuel with oxidizer, or solid fuel with liquid oxidizer. Chemical rockets store a large amount of energy in an released form, can be dangerous. However, careful design, testing and use minimizes risks; the first gunpowder-powered rockets evolved in medieval China under the Song dynasty by the 13th century. The Mongols adopted Chinese rocket technology and the invention spread via the Mongol invasions to the Middle East and to Europe in the mid-13th century. Rockets are recorded in use by the Song navy in a military exercise dated to 1245.
Internal-combustion rocket propulsion is mentioned in a reference to 1264, recording that the "ground-rat", a type of firework, had frightened the Empress-Mother Gongsheng at a feast held in her honor by her son the Emperor Lizong. Subsequently, rockets are included in the military treatise Huolongjing known as the Fire Drake Manual, written by the Chinese artillery officer Jiao Yu in the mid-14th century; this text mentions the first known multistage rocket, the'fire-dragon issuing from the water', thought to have been used by the Chinese navy. Medieval and early modern rockets were used militarily as incendiary weapons in sieges. Between 1270 and 1280, Hasan al-Rammah wrote al-furusiyyah wa al-manasib al-harbiyya, which included 107 gunpowder recipes, 22 of them for rockets. In Europe, Konrad Kyeser described rockets in his military treatise Bellifortis around 1405; the name "rocket" comes from the Italian rocchetta, meaning "bobbin" or "little spindle", given due to the similarity in shape to the bobbin or spool used to hold the thread to be fed to a spinning wheel.
Leonhard Fronsperger and Conrad Haas adopted the Italian term into German in the mid-16th century. Artis Magnae Artilleriae pars prima, an important early modern work on rocket artillery, by Kazimierz Siemienowicz, was first printed in Amsterdam in 1650; the Mysorean rockets were the first successful iron-cased rockets, developed in the late 18th century in the Kingdom of Mysore by Tipu Sultan. The Congreve rocket was a British weapon designed and developed by Sir William Congreve in 1804; this rocket was based directly on the Mysorean rockets, used compressed powder and was fielded in the Napoleonic Wars. It was Congreve rockets that Francis Scott Key was referring to when he wrote of the "rockets' red glare" while held captive on a British ship, laying siege to Fort McHenry in 1814. Together, the Mysorean and British innovations increased the effective range of military rockets from 100 to 2,000 yards; the first mathematical treatment of the dynamics of rocket propulsion is due to William Moore.
In 1815 Alexander Dmitrievich Zasyadko constructed rocket-launching platforms, which allowed rockets to be fired in salvos, gun-laying devices. William Hale in 1844 increased the accuracy of rocket artillery. Edward Mounier Boxer further improved the Congreve rocket in 1865. William Leitch first proposed the concept of using rockets to enable human spaceflight in 1861. Konstantin Tsiolkovsky also conceived this idea, extensively developed a body of theory that has provided the foundation for subsequent spaceflight development. Robert Goddard in 1920 published proposed improvements to rocket technology in A Method of Reaching Extreme Altitudes. In 1923, Hermann Oberth published Die Rakete zu den Planetenräumen Modern rockets originated in 1926 when Goddard attached a supersonic nozzle to the combustion chamber of a liquid-propellant rocket; these nozzles turn the hot gas from the combustion chamber into a cooler, hypersonic directed jet of gas, more than doubling the thrust and raising the engine efficiency from 2% to 64%.
Use of liquid propellants instead of gunpowder improved the effectiveness of rocket artillery in World War II, opened up the p
One for the Angels
"One for the Angels" is the second episode of the American anthology television series The Twilight Zone. It aired on October 9, 1959 on CBS. Lou Bookman is a kindly sidewalk pitchman who sells and repairs toys and trinkets, is adored by the neighborhood children. One day, Bookman is visited by Mr. Death, who tells him that he is to die at midnight of natural causes. Unable to dissuade Death, Bookman instead convinces him to wait until Bookman has made his greatest sales pitch: "one for the angels". Death agrees, Bookman announces he is retiring, smug that he has cheated Death. Death concedes Bookman has found a loophole in their agreement, but warns Bookman that someone else now has to die in his place. Death chooses Maggie, a little girl who lives in Bookman's apartment building and is a friend of his. Maggie falls into a coma. Bookman begs Death to take him instead. Bookman gets out his wares and begins to eloquently boast one item after or another, making the greatest sales pitch of his life—one so great that he entices Death himself.
Death buys item after item and does not remember his appointment with Maggie until it is past midnight, when he has missed it. When Maggie awakens, her doctor leaves the apartment and sees Bookman, assuring him that Maggie will live. Death observes that by making that great sales pitch, Bookman has met the original terms of their deal. Now content and willing to accept his fate, Bookman packs his things and leaves with Death toward Heaven, remarking that "you never know who might need something up there", he looks to Death, adding "Up there?" and Death replies, "Up there, Mr. Bookman. You made it." Ed Wynn as Lewis J. "Lou" Bookman Murray Hamilton as Mr. Death Dana Dillaway as Maggie Polanski Zicree, Marc Scott: The Twilight Zone Companion. Sillman-James Press, 1982 DeVoe, Bill.. Trivia from The Twilight Zone. Albany, GA: Bear Manor Media. ISBN 978-1-59393-136-0 Grams, Martin.. The Twilight Zone: Unlocking the Door to a Television Classic. Churchville, MD: OTR Publishing. ISBN 978-0-9703310-9-0 Sander, Gordon F. Serling: the rise and twilight of television's last angry man.
New York: Penguin Books, 1992. ISBN 0-525-93550-9 "One for the Angels" on IMDb "One for the Angels" at TV.com
Earth is the third planet from the Sun and the only astronomical object known to harbor life. According to radiometric dating and other sources of evidence, Earth formed over 4.5 billion years ago. Earth's gravity interacts with other objects in space the Sun and the Moon, Earth's only natural satellite. Earth revolves around the Sun in a period known as an Earth year. During this time, Earth rotates about its axis about 366.26 times. Earth's axis of rotation is tilted with respect to its orbital plane; the gravitational interaction between Earth and the Moon causes ocean tides, stabilizes Earth's orientation on its axis, slows its rotation. Earth is the largest of the four terrestrial planets. Earth's lithosphere is divided into several rigid tectonic plates that migrate across the surface over periods of many millions of years. About 71% of Earth's surface is covered with water by oceans; the remaining 29% is land consisting of continents and islands that together have many lakes and other sources of water that contribute to the hydrosphere.
The majority of Earth's polar regions are covered in ice, including the Antarctic ice sheet and the sea ice of the Arctic ice pack. Earth's interior remains active with a solid iron inner core, a liquid outer core that generates the Earth's magnetic field, a convecting mantle that drives plate tectonics. Within the first billion years of Earth's history, life appeared in the oceans and began to affect the Earth's atmosphere and surface, leading to the proliferation of aerobic and anaerobic organisms; some geological evidence indicates. Since the combination of Earth's distance from the Sun, physical properties, geological history have allowed life to evolve and thrive. In the history of the Earth, biodiversity has gone through long periods of expansion punctuated by mass extinction events. Over 99% of all species that lived on Earth are extinct. Estimates of the number of species on Earth today vary widely. Over 7.6 billion humans live on Earth and depend on its biosphere and natural resources for their survival.
Humans have developed diverse cultures. The modern English word Earth developed from a wide variety of Middle English forms, which derived from an Old English noun most spelled eorðe, it has cognates in every Germanic language, their proto-Germanic root has been reconstructed as *erþō. In its earliest appearances, eorðe was being used to translate the many senses of Latin terra and Greek γῆ: the ground, its soil, dry land, the human world, the surface of the world, the globe itself; as with Terra and Gaia, Earth was a personified goddess in Germanic paganism: the Angles were listed by Tacitus as among the devotees of Nerthus, Norse mythology included Jörð, a giantess given as the mother of Thor. Earth was written in lowercase, from early Middle English, its definite sense as "the globe" was expressed as the earth. By Early Modern English, many nouns were capitalized, the earth became the Earth when referenced along with other heavenly bodies. More the name is sometimes given as Earth, by analogy with the names of the other planets.
House styles now vary: Oxford spelling recognizes the lowercase form as the most common, with the capitalized form an acceptable variant. Another convention capitalizes "Earth" when appearing as a name but writes it in lowercase when preceded by the, it always appears in lowercase in colloquial expressions such as "what on earth are you doing?" The oldest material found in the Solar System is dated to 4.5672±0.0006 billion years ago. By 4.54±0.04 Bya the primordial Earth had formed. The bodies in the Solar System evolved with the Sun. In theory, a solar nebula partitions a volume out of a molecular cloud by gravitational collapse, which begins to spin and flatten into a circumstellar disk, the planets grow out of that disk with the Sun. A nebula contains gas, ice grains, dust. According to nebular theory, planetesimals formed by accretion, with the primordial Earth taking 10–20 million years to form. A subject of research is the formation of some 4.53 Bya. A leading hypothesis is that it was formed by accretion from material loosed from Earth after a Mars-sized object, named Theia, hit Earth.
In this view, the mass of Theia was 10 percent of Earth, it hit Earth with a glancing blow and some of its mass merged with Earth. Between 4.1 and 3.8 Bya, numerous asteroid impacts during the Late Heavy Bombardment caused significant changes to the greater surface environment of the Moon and, by inference, to that of Earth. Earth's atmosphere and oceans were formed by volcanic outgassing. Water vapor from these sources condensed into the oceans, augmented by water and ice from asteroids and comets. In this model, atmospheric "greenhouse gases" kept the oceans from freezing when the newly forming Sun had only 70% of its current luminosity. By 3.5 Bya, Earth's magnetic field was established, which helped prevent the atmosphere from being stripped away by the solar wind. A crust formed; the two models that explain land mass propose either a steady growth to the present-day forms or, more a rapid growth early in Earth history followed by a long-term steady continental area. Continents formed by plate tectonics