vania-janet/multiturn-rag-retrieval-data huggingface dataset:
United States
The United States often opposed Third World movements that it viewed as Soviet - sponsored , and occasionally pursued direct action for regime change against left - wing governments . American troops fought communist Chinese and North Korean forces in the Korean War of 1950 -- 53 . The Soviet Union 's 1957 launch of the first artificial satellite and its 1961 launch of the first manned spaceflight initiated a `` Space Race '' in which the United States became the first nation to land a man on the moon in 1969 . A proxy war in Southeast Asia eventually evolved into full American participation , as the Vietnam War .
Space Race
The N1 / L3 launch vehicle had three stages to Earth orbit , a fourth stage for Earth departure , and a fifth stage for lunar landing assist . The combined space vehicle was roughly the same height and takeoff mass as the three - stage US Apollo / Saturn V and exceeded its takeoff thrust by 28 % , but had only roughly half the translunar injection payload capability .
Great Wall of China
One of the earliest known references to the myth that the Great Wall can be seen from the moon appears in a letter written in 1754 by the English antiquary William Stukeley . Stukeley wrote that , `` This mighty wall ( Hadrian 's wall ) of four score miles ( 130 km ) in length is only exceeded by the Chinese Wall , which makes a considerable figure upon the terrestrial globe , and may be discerned at the Moon . '' The claim was also mentioned by Henry Norman in 1895 where he states `` besides its age it enjoys the reputation of being the only work of human hands on the globe visible from the Moon . '' The issue of `` canals '' on Mars was prominent in the late 19th century and may have led to the belief that long , thin objects were visible from space . The claim that the Great Wall is visible from the moon also appears in 1932 's Ripley 's Believe It or Not ! strip and in Richard Halliburton 's 1938 book Second Book of Marvels .
Moon landing
China is planning to land another rover and collect samples in the Chang'e 4 mission and return lunar soil samples by 2018 in the Chang'e 5 mission .
Great Scott
A large basalt rock collected by astronaut David Scott on the Apollo 15 mission to the moon in 1971 is informally known as Great Scott .
Chicxulub crater
The main evidence of such an impact , besides the crater itself , is contained in a thin layer of clay present in the K -- Pg boundary across the world . In the late 1970s , the Alvarezes and colleagues reported that it contained an abnormally high concentration of iridium . Iridium levels in this layer reached 6 parts per billion by weight or more compared to 0.4 for the Earth 's crust as a whole ; in comparison , meteorites can contain around 470 parts per billion of this element . It was hypothesized that the iridium was spread into the atmosphere when the impactor was vaporized and settled across the Earth 's surface amongst other material thrown up by the impact , producing the layer of iridium - enriched clay . Similarly , an iridium anomaly in core samples from the Pacific Ocean suggested the Eltanin impact of about 2.5 million years ago .
Moon landing
The U.S. robotic Surveyor program was part of an effort to locate a safe site on the Moon for a human landing and test under lunar conditions the radar and landing systems required to make a true controlled touchdown . Five of Surveyor 's seven missions made successful unmanned Moon landings . Surveyor 3 was visited two years after its Moon landing by the crew of Apollo 12 . They removed parts of it for examination back on Earth to determine the effects of long - term exposure to the lunar environment .
Mars
In 2005 , radar data revealed the presence of large quantities of water ice at the poles and at mid-latitudes . The Mars rover Spirit sampled chemical compounds containing water molecules in March 2007 . The Phoenix lander directly sampled water ice in shallow Martian soil on July 31 , 2008 . On September 28 , 2015 , NASA announced the presence of briny flowing salt water on the Martian surface .
Moon landing
The Lunar Precursor Robotic Program ( LPRP ) is a program of robotic spacecraft missions which NASA will use to prepare for future Moon landings . Three orbiters have been launched in the program , the Lunar Reconnaissance Orbiter ( LRO ) , the Lunar Crater Observation and Sensing Satellite ( LCROSS ) , and the Lunar Atmosphere and Dust Environment Explorer ( LADEE ) , launched in 2013 , but no Moon landings are scheduled yet .
Moon landing
In contrast , manned vehicles need additional fuel after a lunar landing to enable a return trip back to Earth for the crew . Leaving this massive amount of required Earth - return fuel in lunar orbit until it is used later in the mission is far more efficient than taking such fuel down to the lunar surface in a Moon landing and then hauling it all back into space yet again , working against lunar gravity both ways . Such considerations lead logically to a lunar orbit rendezvous mission profile for a manned Moon landing .
Mars
The Curiosity rover , which landed on Mars in August 2012 , is able to make measurements that distinguish between different isotopologues of methane , but even if the mission is to determine that microscopic Martian life is the source of the methane , the life forms likely reside far below the surface , outside of the rover 's reach . The first measurements with the Tunable Laser Spectrometer ( TLS ) indicated that there is less than 5 ppb of methane at the landing site at the point of the measurement . On September 19 , 2013 , NASA scientists , from further measurements by Curiosity , reported no detection of atmospheric methane with a measured value of 6999180000000000000 ♠ 0.18 ± 0.67 ppbv corresponding to an upper limit of only 1.3 ppbv ( 95 % confidence limit ) and , as a result , conclude that the probability of current methanogenic microbial activity on Mars is reduced .
Moon landing
All Apollo lunar missions had a third crew member who remained on board the Command Module . The last three missions had a rover for increased mobility .
Venus
The Venusian surface was a subject of speculation until some of its secrets were revealed by planetary science in the 20th century . Venera landers in 1975 and 1982 returned images of a surface covered in sediment and relatively angular rocks . The surface was mapped in detail by Magellan in 1990 -- 91 . The ground shows evidence of extensive volcanism , and the sulfur in the atmosphere may indicate that there have been some recent eruptions .
Mars
On March 18 , 2013 , NASA reported evidence from instruments on the Curiosity rover of mineral hydration , likely hydrated calcium sulfate , in several rock samples including the broken fragments of `` Tintina '' rock and `` Sutton Inlier '' rock as well as in veins and nodules in other rocks like `` Knorr '' rock and `` Wernicke '' rock . Analysis using the rover 's DAN instrument provided evidence of subsurface water , amounting to as much as 4 % water content , down to a depth of 60 cm ( 24 in ) , during the rover 's traverse from the Bradbury Landing site to the Yellowknife Bay area in the Glenelg terrain . In September 2015 , NASA announced that they had found conclusive evidence of hydrated brine flows on recurring slope lineae , based on spectrometer readings of the darkened areas of slopes . These observations provided confirmation of earlier hypotheses based on timing of formation and their rate of growth , that these dark streaks resulted from water flowing in the very shallow subsurface . The streaks contain hydrated salts , perchlorates , which have water molecules in their crystal structure . The streaks flow downhill in Martian summer , when the temperature is above − 23 degrees Celsius , and freeze at lower temperatures .
Exploration of Mars
In 2001 , NASA 's Mars Odyssey orbiter arrived at Mars . Its mission is to use spectrometers and imagers to hunt for evidence of past or present water and volcanic activity on Mars . In 2002 , it was announced that the probe 's gamma - ray spectrometer and neutron spectrometer had detected large amounts of hydrogen , indicating that there are vast deposits of water ice in the upper three meters of Mars ' soil within 60 ° latitude of the south pole .
Moon landing
Indian Space Research Organisation ( ISRO ) performed a controlled crash impact with its Moon Impact Probe ( MIP ) on 14 November 2008 . The MIP was an ejected probe from the Indian Chandrayaan - 1 lunar orbiter and performed remote sensing experiments during its descent to the lunar surface .
Exploration of Mars
On 24 January 2014 , NASA reported that current studies on the planet Mars by the Curiosity and Opportunity rovers will search for evidence of ancient life , including a biosphere based on autotrophic , chemotrophic and / or chemolithoautotrophic microorganisms , as well as ancient water , including fluvio - lacustrine environments ( plains related to ancient rivers or lakes ) that may have been habitable . The search for evidence of habitability , taphonomy ( related to fossils ) , and organic carbon on the planet Mars is now a primary NASA objective . Play
Moon landing
Zond 5 was the first spacecraft to carry life from Earth to the vicinity of the Moon and return , initiating the final lap of the Space Race with its payload of turtles , insects , plants and bacteria . Despite the failure suffered in its final moments , the Zond 6 mission was reported by Soviet media as being a success as well . Although hailed worldwide as remarkable achievements , both of these Zond missions flew off - nominal reentry trajectories resulting in deceleration forces that would have been fatal to human crewmembers had they been aboard .
Apollo
In spaceflight , the NASA program for landing astronauts on the Moon was named Apollo .
Mars
On December 16 , 2014 , NASA reported the Curiosity rover detected a `` tenfold spike '' , likely localized , in the amount of methane in the Martian atmosphere . Sample measurements taken `` a dozen times over 20 months '' showed increases in late 2013 and early 2014 , averaging `` 7 parts of methane per billion in the atmosphere . '' Before and after that , readings averaged around one - tenth that level .
Moon landing
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Earth
Large deposits of fossil fuels are obtained from Earth 's crust , consisting of coal , petroleum , and natural gas . These deposits are used by humans both for energy production and as feedstock for chemical production . Mineral ore bodies have also been formed within the crust through a process of ore genesis , resulting from actions of magmatism , erosion , and plate tectonics . These bodies form concentrated sources for many metals and other useful elements .
Space Race
Apollo 11 was prepared with the goal of a July landing in the Sea of Tranquility . The crew , selected in January 1969 , consisted of commander ( CDR ) Neil Armstrong , Command Module Pilot ( CMP ) Michael Collins , and Lunar Module Pilot ( LMP ) Edwin `` Buzz '' Aldrin . They trained for the mission until just before the launch day . On July 16 , 1969 , at exactly 9 : 32 am EDT , the Saturn V rocket , AS - 506 , lifted off from Kennedy Space Center Launch Complex 39 in Florida .
Mars
Further evidence that liquid water once existed on the surface of Mars comes from the detection of specific minerals such as hematite and goethite , both of which sometimes form in the presence of water . In 2004 , Opportunity detected the mineral jarosite . This forms only in the presence of acidic water , which demonstrates that water once existed on Mars . More recent evidence for liquid water comes from the finding of the mineral gypsum on the surface by NASA 's Mars rover Opportunity in December 2011 . It is believed that the amount of water in the upper mantle of Mars , represented by hydroxyl ions contained within the minerals of Mars 's geology , is equal to or greater than that of Earth at 50 -- 300 parts per million of water , which is enough to cover the entire planet to a depth of 200 -- 1,000 m ( 660 -- 3,280 ft ) .
Nickel
Stable isotope nickel - 60 is the daughter product of the extinct radionuclide Fe , which decays with a half - life of 2.6 million years . Because Fe has such a long half - life , its persistence in materials in the solar system may generate observable variations in the isotopic composition of Ni . Therefore , the abundance of Ni present in extraterrestrial material may provide insight into the origin of the solar system and its early history .
Mars
In situ investigations have been performed on Mars by the Viking landers , Spirit and Opportunity rovers , Phoenix lander , and Curiosity rover . Evidence suggests that the planet was once significantly more habitable than it is today , but whether living organisms ever existed there remains unknown . The Viking probes of the mid-1970s carried experiments designed to detect microorganisms in Martian soil at their respective landing sites and had positive results , including a temporary increase of CO production on exposure to water and nutrients . This sign of life was later disputed by scientists , resulting in a continuing debate , with NASA scientist Gilbert Levin asserting that Viking may have found life . A re-analysis of the Viking data , in light of modern knowledge of extremophile forms of life , has suggested that the Viking tests were not sophisticated enough to detect these forms of life . The tests could even have killed a ( hypothetical ) life form . Tests conducted by the Phoenix Mars lander have shown that the soil has a alkaline pH and it contains magnesium , sodium , potassium and chloride . The soil nutrients may be able to support life , but life would still have to be shielded from the intense ultraviolet light . A recent analysis of martian meteorite EETA79001 found 0.6 ppm ClO − 4 , 1.4 ppm ClO − 3 , and 16 ppm NO − 3 , most likely of Martian origin . The ClO − 3 suggests the presence of other highly oxidizing oxychlorines , such as ClO − 2 or ClO , produced both by UV oxidation of Cl and X-ray radiolysis of ClO − 4 . Thus , only highly refractory and / or well - protected ( sub-surface ) organics or life forms are likely to survive .
Moon landing
While NASA stressed peaceful and scientific uses for these rockets , their use in various lunar exploration efforts also had secondary goal of realistic , goal - oriented testing of the missiles themselves and development of associated infrastructure , just as the Soviets were doing with their R - 7 .
Chicxulub crater
A deep drilling into the inner ring of the Chicxulub crater . It found , from top down : Thick Cenozoic limestone . A graded sediment deposit from one tsunami , over 100 meters thick . Impact - melted rock and shocked quartz . This did not contain the calcium sulphate that the rocks in the area around contain , leading the program makers to conclude that all the calcium sulphate in the crater area had been evaporated into the atmosphere and had become a dense sulphur dioxide veil stopping the sunlight . In a quarry in New Jersey , a dense marine bone bed on the Cretaceous - Tertiary boundary containing a mixture of dead sea animals with little or no damage from scavengers or predators , and land animals and parts of trees washed into the sea by a tsunami . In Patagonia a dense dinosaur bone bed on the Cretaceous - Tertiary boundary .
Moon landing
Heat sterilization was discontinued for the final four Block III Ranger probes . These replaced the Block II landing capsule and its retrorocket with a heavier , more capable television system to support landing site selection for upcoming Apollo manned Moon landing missions . Six cameras were designed to take thousands of high - altitude photographs in the final twenty - minute period before crashing on the lunar surface . Camera resolution was 1,132 scan lines , far higher than the 525 lines found in a typical U.S. 1964 home television . While Ranger 6 suffered a failure of this camera system and returned no photographs despite an otherwise successful flight , the subsequent Ranger 7 mission to Mare Cognitum was a complete success .
Moon landing
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Space Race
Korolev 's lunar landing program was designated N1 / L3 , for its N1 super rocket and a more advanced Soyuz 7K - L3 spacecraft , also known as the lunar orbital module ( `` Lunniy Orbitalny Korabl '' , LOK ) , with a crew of two . A separate lunar lander ( `` Lunniy Korabl '' , LK ) , would carry a single cosmonaut to the lunar surface .
Moon landing
Accordingly , beginning in mid-1966 both the U.S. and U.S.S.R. naturally progressed into missions which featured lunar orbit operations as a necessary prerequisite to a manned Moon landing . The primary goals of these initial unmanned orbiters were extensive photographic mapping of the entire lunar surface for the selection of manned landing sites and , for the Soviets , the checkout of radio communications gear that would be used in future soft landings .
Moon landing
Achieving a manned circumlunar loop flight prior to a manned lunar landing became a primary goal of the Soviets with their Zond spacecraft program . The first three Zonds were unmanned planetary probes ; after that , the Zond name was transferred to a completely separate manned program . The initial focus of these later Zonds was extensive testing of required high - speed reentry techniques . This focus was not shared by the U.S. , who chose instead to bypass the stepping stone of a manned circumlunar loop mission and never developed a separate spacecraft for this purpose .
Elgin Marbles
The collection held in the British Museum includes the following material from the Acropolis :
Chicxulub crater
The emission of dust and particles could have covered the entire surface of the Earth for several years , possibly a decade , creating a harsh environment for living things . The shock production of carbon dioxide caused by the destruction of carbonate rocks would have led to a sudden greenhouse effect . Over a longer period , sunlight would have been blocked from reaching the surface of the Earth by the dust particles in the atmosphere , cooling the surface dramatically . Photosynthesis by plants would also have been interrupted , affecting the entire food chain . A model of the event developed by Lomax et al. ( 2001 ) suggests that net primary productivity ( NPP ) rates may have increased to higher than pre-impact levels over the long term because of the high carbon dioxide concentrations .
Hydrothermal vent
Attempts have been made in the past to exploit minerals from the seafloor . The 1960s and 70s saw a great deal of activity ( and expenditure ) in the recovery of manganese nodules from the abyssal plains , with varying degrees of success . This does demonstrate however that recovery of minerals from the seafloor is possible , and has been possible for some time . Interestingly , mining of manganese nodules served as a cover story for the elaborate attempt in 1974 by the CIA to raise the sunken Soviet submarine K - 129 , using the Glomar Explorer , a ship purpose built for the task by Howard Hughes . The operation was known as Project Azorian , and the cover story of seafloor mining of manganese nodules may have served as the impetus to propel other companies to make the attempt .
Nickel
Radioactive nickel - 56 is produced by the silicon burning process and later set free in large quantities during type Ia supernovae . The shape of the light curve of these supernovae at intermediate to late - times corresponds to the decay via electron capture of nickel - 56 to cobalt - 56 and ultimately to iron - 56 . Nickel - 59 is a long - lived cosmogenic radionuclide with a half - life of 76,000 years . Ni has found many applications in isotope geology . Ni has been used to date the terrestrial age of meteorites and to determine abundances of extraterrestrial dust in ice and sediment . Nickel - 78 's half - life was recently measured at 110 milliseconds , and is believed an important isotope in supernova nucleosynthesis of elements heavier than iron . The nuclide Ni , discovered in 1999 , is the most proton - rich heavy element isotope known . With 28 protons and 20 neutrons Ni is `` double magic '' , as is Ni with 28 protons and 50 neutrons . Both are therefore unusually stable for nuclides with so large a proton - neutron imbalance .
Moon landing
The U.S. response to these Soviet achievements was to greatly accelerate previously existing military space and missile projects and to create a civilian space agency , NASA . Military efforts were initiated to develop and produce mass quantities of intercontinental ballistic missiles ( ICBMs ) that would bridge the so - called missile gap and enable a policy of deterrence to nuclear war with the Soviets known as mutual assured destruction or MAD . These newly developed missiles were made available to civilians of NASA for various projects ( which would have the added benefit of demonstrating the payload , guidance accuracy and reliabilities of U.S. ICBMs to the Soviets ) .
Exploration of Mars
NASA 's Mars Odyssey orbiter entered Mars orbit in 2001 . Odyssey 's Gamma Ray Spectrometer detected significant amounts of hydrogen in the upper metre or so of regolith on Mars . This hydrogen is thought to be contained in large deposits of water ice .
Wetland
Nutrient retention : Wetlands cycle both sediments and nutrients balancing terrestrial and aquatic ecosystems . A natural function of wetland vegetation is the up - take and storage of nutrients found in the surrounding soil and water . These nutrients are retained in the system until the plant dies or is harvested by animals or humans . Wetland vegetation productivity is linked to the climate , wetland type , and nutrient availability . The grasses of fertile floodplains such as the Nile produce the highest yield including plants such as Arundo donax ( giant reed ) , Cyperus papyrus ( papyrus ) , Phragmites ( reed ) and Typha ( cattail , bulrush ) .
Helium
After an oil drilling operation in 1903 in Dexter , Kansas , produced a gas geyser that would not burn , Kansas state geologist Erasmus Haworth collected samples of the escaping gas and took them back to the University of Kansas at Lawrence where , with the help of chemists Hamilton Cady and David McFarland , he discovered that the gas consisted of , by volume , 72 % nitrogen , 15 % methane ( a combustible percentage only with sufficient oxygen ) , 1 % hydrogen , and 12 % an unidentifiable gas . With further analysis , Cady and McFarland discovered that 1.84 % of the gas sample was helium . This showed that despite its overall rarity on Earth , helium was concentrated in large quantities under the American Great Plains , available for extraction as a byproduct of natural gas .
Storm drain
Water running off these impervious surfaces tends to pick up gasoline , motor oil , heavy metals , trash and other pollutants from roadways and parking lots , as well as fertilizers and pesticides from lawns . Roads and parking lots are major sources of nickel , copper , zinc , cadmium , lead and polycyclic aromatic hydrocarbons ( PAHs ) , which are created as combustion byproducts of gasoline and other fossil fuels . Roof runoff contributes high levels of synthetic organic compounds and zinc ( from galvanized gutters ) . Fertilizer use on residential lawns , parks and golf courses is a significant source of nitrates and phosphorus .