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Wonders Of The Solar System
''Wonders of the Solar System'' is a 2010 television series co-produced by the BBC and Science Channel, and hosted by physicist Brian Cox. ''Wonders of the Solar System'' was first broadcast in the United Kingdom on BBC Two on 7 March 2010. The series comprises five episodes, each of which focuses on an aspect of the Solar System and features a 'wonder' relevant to the theme. The series was described as one of the most successful to appear on BBC Two in recent years. An accompanying book with the same name was also published. On 31 March 2011, the series won the prestigious George Foster Peabody Award for excellence in documentary film-making. Episodes 1. "Empire of the Sun" The first episode illustrates how the formation and behaviour of the Sun affects each planet in the Solar System. During this episode, Cox visits India to view and explain the workings of a total solar eclipse and the partial eclipses that occur on other planets. He travels to the Iguazu Falls to relate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard-definition Television
Standard-definition television (SDTV, SD, often shortened to standard definition) is a television system which uses a resolution that is not considered to be either high or enhanced definition. "Standard" refers to it being the prevailing specification for broadcast (and later, cable) television in the mid- to late-20th century, and compatible with legacy analog broadcast systems. The two common SDTV signal types are 576i, with 576 interlaced lines of resolution, derived from the European-developed PAL and SECAM systems, and 480i based on the American NTSC system. Common SDTV refresh rates are 25, 29.97 and 30 frames per second. Both systems use a 4:3 aspect ratio. Standards that support digital SDTV broadcast include DVB, ATSC, and ISDB. The last two were originally developed for HDTV, but are also used for their ability to deliver multiple SD video and audio streams via multiplexing. In North America, digital SDTV is broadcast in the same 4:3 aspect ratio as NTSC si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Death Valley
Death Valley is a desert valley in Eastern California, in the northern Mojave Desert, bordering the Great Basin Desert. During summer, it is the Highest temperature recorded on Earth, hottest place on Earth. Death Valley's Badwater Basin is the point of lowest elevation in North America, at below sea level. It is east-southeast of Mount Whitney — the highest point in the contiguous United States, with an elevation of 14,505 feet (4,421 m). On the afternoon of July10, 1913, the National Weather Service, United States Weather Bureau recorded a high temperature of 134 °F (56.7 °C) at Furnace Creek, California, Furnace Creek in Death Valley, which stands as the Highest temperature recorded on Earth, highest ambient air temperature ever recorded on the surface of the Earth. This reading, however, and several others taken in that period are disputed by some modern experts. Lying mostly in Inyo County, California, near the border of California and Nevada, in the Great ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retrograde And Prograde Motion
Retrograde motion in astronomy is, in general, orbital or rotational motion of an object in the direction opposite the rotation of its primary, that is, the central object (right figure). It may also describe other motions such as precession or nutation of an object's rotational axis. Prograde or direct motion is more normal motion in the same direction as the primary rotates. However, "retrograde" and "prograde" can also refer to an object other than the primary if so described. The direction of rotation is determined by an inertial frame of reference, such as distant fixed stars. In the Solar System, the orbits around the Sun of all planets and most other objects, except many comets, are prograde. They orbit around the Sun in the same direction as the sun rotates about its axis, which is counterclockwise when observed from above the Sun's north pole. Except for Venus and Uranus, planetary rotations around their axes are also prograde. Most natural satellites have prograde or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlas Mountains
The Atlas Mountains are a mountain range in the Maghreb in North Africa. It separates the Sahara Desert from the Mediterranean Sea and the Atlantic Ocean; the name "Atlantic" is derived from the mountain range. It stretches around through Morocco, Algeria and Tunisia. The range's highest peak is Toubkal, which is in central Morocco, with an elevation of . The Atlas mountains are primarily inhabited by Berbers, Berber populations. The terms for 'mountain' are ''Adrar'' and ''adras'' in some Berber languages, and these terms are believed to be cognates of the Toponymy, toponym ''Atlas''. The mountains are also home to a number of animals and plants which are mostly found within Africa but some of which can be found in Europe. Many of these species are endangered and a few are already extinct. The weather is cooling but has sunny summers, and the average temperature there is 25°C.Atlas Mountains are a mountain range in the Maghreb in North Africa. It separates the Sahara Desert fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Al-Qayrawan
Kairouan (, ), also spelled El Qayrawān or Kairwan ( ar, ٱلْقَيْرَوَان, al-Qayrawān , aeb, script=Latn, Qeirwān ), is the capital of the Kairouan Governorate in Tunisia and a UNESCO World Heritage Site. The city was founded by the Umayyads around 670, in the period of Caliph Mu'awiya (reigned 661–680); this is when it became an important centre for Sunni Islamic scholarship and Quranic learning, attracting Muslims from various parts of the world, next only to Mecca, Medina and Jerusalem. The Mosque of Uqba is situated in the city.Europa Publications "General Survey: Holy Places" ''The Middle East and North Africa 2003'', p. 147. Routledge, 2003. . "The city is regarded as a holy place for Muslims." In 2014, the city had about 187,000 inhabitants. Etymology The name ( ''al-Qayrawān'') is an Arabic word meaning "military group" or "caravan", borrowed early on from the Middle Persian word ''kārawān'' (modern Persian ''kârvân''), meaning "military column" ('' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hertzsprung–Russell Diagram
The Hertzsprung–Russell diagram, abbreviated as H–R diagram, HR diagram or HRD, is a scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosity, luminosities versus their stellar classifications or effective temperatures. The diagram was created independently in 1911 by Ejnar Hertzsprung and by Henry Norris Russell in 1913, and represented a major step towards an understanding of stellar evolution. Historical background In the nineteenth century large-scale photographic spectroscopic surveys of stars were performed at Harvard College Observatory, producing spectral classifications for tens of thousands of stars, culminating ultimately in the Henry Draper Catalogue. In one segment of this work Antonia Maury included divisions of the stars by the width of their spectral lines. Hertzsprung noted that stars described with narrow lines tended to have smaller proper motions than the others of the same spectral classification. He took this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term ''Milky Way'' is a translation of the Latin ', from the Greek ('), meaning "milky circle". From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies. The Milky Way is a barred spiral galaxy with an estimated D25 isophotal diameter of , but only about 1,000 light years thick at the spiral arms (more at the bulg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paranal Observatory
Paranal Observatory is an astronomical observatory operated by the European Southern Observatory (ESO). It is located in the Atacama Desert of northern Chile on Cerro Paranal at altitude, south of Antofagasta. By total light-collecting area, it is the largest optical-infrared observatory in the Southern Hemisphere; worldwide, it is second to the Mauna Kea Observatory on Hawaii. The Very Large Telescope (VLT), the largest telescope on Paranal, is composed of four separate telescopes. In addition, the four main telescopes can be used simultaneously for extra light gathering capacity, and for interferometry. Four auxiliary telescopes of each are also part of the VLTI to make it available when the main telescopes are being used for other projects. The site also houses two survey telescopes with wide fields of view, the VISTA and the VLT Survey Telescope for surveying large areas of the sky; and two arrays of small telescopes called NGTS and SPECULOOS which are dedicated to searc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atacama Desert
The Atacama Desert ( es, Desierto de Atacama) is a desert plateau in South America covering a 1,600 km (990 mi) strip of land on the Pacific coast, west of the Andes Mountains. The Atacama Desert is the driest nonpolar desert in the world, and the second driest overall, just behind some very specific spots within the McMurdo Dry Valleys as well as the only hot true desert to receive less precipitation than the polar deserts, and the largest fog desert in the world. Both regions have been used as experimentation sites on Earth for Mars expedition simulations. The Atacama Desert occupies , or if the barren lower slopes of the Andes are included. Most of the desert is composed of stony terrain, salt lakes (''salares''), sand, and felsic lava that flows towards the Andes. The desert owes its extreme aridity to a constant temperature inversion due to the cool north-flowing Humboldt ocean current and to the presence of the strong Pacific anticyclone. The most arid re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outer Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar System" and "solar system" structures in theinaming guidelines document. The name is commonly rendered in lower case ('solar system'), as, for example, in the ''Oxford English Dictionary'' an''Merriam-Webster's 11th Collegiate Dictionary''. is the gravitationally bound system of the Sun and the objects that orbit it. It formed 4.6 billion years ago from the gravitational collapse of a giant interstellar molecular cloud. The vast majority (99.86%) of the system's mass is in the Sun, with most of the remaining mass contained in the planet Jupiter. The four inner system planets—Mercury, Venus, Earth and Mars—are terrestrial planets, being composed primarily of rock and metal. The four giant planets of the outer system are substant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aurora Borealis
An aurora (plural: auroras or aurorae), also commonly known as the polar lights, is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic). Auroras display dynamic patterns of brilliant lights that appear as curtains, rays, spirals, or dynamic flickers covering the entire sky. Auroras are the result of disturbances in the magnetosphere caused by the solar wind. Major disturbances result from enhancements in the speed of the solar wind from coronal holes and coronal mass ejections. These disturbances alter the trajectories of charged particles in the magnetospheric plasma. These particles, mainly electrons and protons, precipitate into the upper atmosphere (thermosphere/ exosphere). The resulting ionization and excitation of atmospheric constituents emit light of varying colour and complexity. The form of the aurora, occurring within bands around both polar regions, is also dependent on the amount of accelerati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Wind
The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona. This plasma mostly consists of electrons, protons and alpha particles with kinetic energy between . The composition of the solar wind plasma also includes a mixture of materials found in the solar plasma: trace amounts of heavy ions and atomic nuclei such as C, N, O, Ne, Mg, Si, S, and Fe. There are also rarer traces of some other nuclei and isotopes such as P, Ti, Cr, 54Fe and 56Fe, and 58Ni, 60Ni, and 62Ni. Superposed with the solar-wind plasma is the interplanetary magnetic field. The solar wind varies in density, temperature and speed over time and over solar latitude and longitude. Its particles can escape the Sun's gravity because of their high energy resulting from the high temperature of the corona, which in turn is a result of the coronal magnetic field. The boundary separating the corona from the solar wind is called the Alfvén surface. At a distance of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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